Prognosis for the co-twin following single-twin death: a systematic review

Vanishing twins, spared cohorts, and the birthweight of periviable infants born to Black and white women in the United States

Pregnancies ending before 26 weeks contribute 1% of births but 40% of infant deaths in the United States. The rate of these "periviable" births to non-Hispanic (NH) Black women exceeds four times that for NH whites. Small male periviable infants remain most likely to die. NH white periviable males weigh more than their NH Black counterparts. We argue that male infants born from twin gestations, in which one fetus died in utero (i.e., the vanishing twin syndrome), contribute to the disparity. We cannot directly test our argument because "vanishing" typically occurs before clinical recognition of pregnancy. We, however, describe and find associations that would emerge in vital statistics were our argument correct. Among male periviable singleton births from 288 monthly conception cohorts (January 1995 through December 2018), we found an average NH white advantage of 30 grams (759 grams versus 729 grams). Consistent with our argument, however, cohorts signaling relatively few survivors of the vanishing twin syndrome showed no disparity.

Dichorionic triamniotic triplets after two blastocysts transfer underwent multifetal pregnancy reduction: two case reports and literature review

BACKGROUND

The increase in the rate of multiple pregnancies in clinical practice is associated with assisted reproductive technology (ART). Given the high risk of dichorionic triamniotic (DCTA) triplet pregnancies, reducing DCTA triplet pregnancies to twin or singleton pregnancies is often beneficial.

CASE PRESENTATION

This article reports on two cases of DCTA triplet pregnancies resulting from two blastocyst transfers. Given the high risk of complications such as twin-to-twin transfusion syndrome (TTTS) in monochorionic diamniotic (MCDA) twin pregnancies, patients have a strong desire to preserve the dichorionic diamniotic (DCDA) twins. Multifetal pregnancy reduction (MFPR) was performed in both cases to continue the pregnancy with DCDA twins by reducing one of the MCDA twins. Both of the pregnant women in this report eventually gave birth to healthy twins at 37 weeks.

CONCLUSIONS

For infertile couples with multiple pregnancies but with a strong desire to remain the DCDA twins, our report suggests that reducing DCTA triplets to DCDA twin pregnancies may be an option based on clinical operability and assessment of surgical difficulty.

PLEKHG1: New Potential Candidate Gene for Periventricular White Matter Abnormalities

Hypoxic-ischemic brain damage presents a significant neurological challenge, often manifesting during the perinatal period. Specifically, periventricular leukomalacia (PVL) is emerging as a notable contributor to cerebral palsy and intellectual disabilities. It compromises cerebral microcirculation, resulting in insufficient oxygen or blood flow to the periventricular region of the brain. As widely documented, these pathological conditions can be caused by several factors encompassing preterm birth (4-5% of the total cases), as well single cotwin abortion and genetic variants such as those associated with GTPase pathways. Whole exome sequencing (WES) analysis identified a de novo causative variant within the pleckstrin homology domain-containing family G member 1 (PLEKHG1) gene in a patient presenting with PVL. The PLEKHG1 gene is ubiquitously expressed, showing high expression patterns in brain tissues. PLEKHG1 is part of a family of Rho guanine nucleotide exchange factors, and the protein is essential for cell division control protein 42 (CDC42) activation in the GTPase pathway. CDC42 is a key small GTPase of the Rho-subfamily, regulating various cellular functions such as cell morphology, migration, endocytosis, and cell cycle progression. The molecular mechanism involving PLEKHG1 and CDC42 has an intriguing role in the reorientation of cells in the vascular endothelium, thus suggesting that disruption responses to mechanical stress in endothelial cells may be involved in the formation of white matter lesions. Significantly, CDC42 association with white matter abnormalities is underscored by its MIM phenotype number. In contrast, although PLEKHG1 has been recently associated with patients showing white matter hyperintensities, it currently lacks a MIM phenotype number. Additionally, in silico analyses classified the identified variant as pathogenic. Although the patient was born prematurely and subsequently to dichorionic gestation, during which its cotwin died, we suggest that the variant described can strongly contribute to PVL. The aim of the current study is to establish a plausible association between the PLEKHG1 gene and PVL.

[Fetal death: Expert consensus from the College of French Gynecologists and Obstetricians]

Fetal death is defined as the spontaneous cessation of cardiac activity after fourteen weeks of amenorrhea. In France, the prevalence of fetal death after 22 weeks is between 3.2 and 4.4/1000 births. Regarding the prevention of fetal death in the general population, it is not recommended to counsel for rest and not to prescribe vitamin A, vitamin D nor micronutrient supplementation for the sole purpose of reducing the risk of fetal death (Weak recommendations; Low quality of evidence). It is not recommended to prescribe aspirin (Weak recommendation; Very low quality of evidence). It is recommended to offer vaccination against influenza in epidemic periods and against SARS-CoV-2 (Strong recommendations; Low quality of evidence). It is not recommended to systematically look for nuchal cord encirclements during prenatal screening ultrasounds (Strong Recommendation; Low Quality of Evidence) and not to perform systematic antepartum monitoring by cardiotocography (Weak Recommendation; Very Low Quality of Evidence). It is not recommended to ask women to perform an active fetal movement count to reduce the risk of fetal death (Strong Recommendation; High Quality of Evidence). Regarding evaluation in the event of fetal death, it is suggested that an external fetal examination be systematically offered (Expert opinion). It is recommended that a fetopathological and anatomopathological examination of the placenta be carried out to participate in cause identification (Strong Recommendation. Moderate quality of evidence). It is recommended that chromosomal analysis by microarray testing be performed rather than conventional karyotype, in order to be able to identify a potentially causal anomaly more frequently (Strong Recommendation, moderate quality of evidence); to this end, it is suggested that postnatal sampling of the placental fetal surface for genetic purposes be preferred (Expert Opinion). It is suggested to test for antiphospholipid antibodies and systematically perform a Kleihauer test and a test for irregular agglutinins (Expert opinion). It is suggested to offer a summary consultation, with the aim of assessing the physical and psychological status of the parents, reporting the results, discussing the cause and providing information on monitoring for a subsequent pregnancy (Expert opinion). Regarding announcement and support, it is suggested to announce fetal death without ambiguity, using simple words and adapting to each situation, and then to support couples with empathy in the various stages of their care (Expert opinion). Regarding management, it is suggested that, in the absence of a situation at risk of disseminated intravascular coagulation or maternal vitality, the patient's wishes should be taken into account when determining the time between the diagnosis of fetal death and induction of birth. Returning home is possible if it's the patient wish (Expert opinion). In all situations excluding maternal life-threatening emergencies, the preferred mode of delivery is vaginal delivery, regardless the history of cesarean section(s) history (Expert opinion). In the event of fetal death, it is recommended that mifepristone 200mg be prescribed at least 24hours before induction, to reduce the delay between induction and delivery (Low recommendation. Low quality of evidence). There are insufficient data in the literature to make a recommendation regarding the route of administration (vaginal or oral) of misoprostol, neither the type of prostaglandin to reduce induction-delivery time or maternal morbidity. It is suggested that perimedullary analgesia be introduced at the start of induction if the patient asks, regardless of gestational age. It is suggested to prescribe cabergoline immediately in the postpartum period in order to avoid lactation, whatever the gestational age, after discussing the side effects of the treatment with the patient (Expert opinion). The risk of recurrence of fetal death after unexplained fetal death does not appear to be increased in subsequent pregnancies, and data from the literature are insufficient to make a recommendation on the prescription of aspirin. In the event of a history of fetal death due to vascular issues, low-dose aspirin is recommended to reduce perinatal morbidity, and should not be combined with heparin therapy (Low recommendation, very low quality of evidence). It is suggested not to recommend an optimal delay before initiating another pregnancy just because of the history of fetal death. It is suggested that the woman and co-parent be informed of the possibility of psychological support. Fetal heart rate monitoring is not indicated solely because of a history of fetal death. It is suggested that delivery not be systematically induced. However, induction can be considered depending on the context and parental request. The gestational age will be discussed, taking into account the benefits and risks, especially before 39 weeks. If a cause of fetal death is identified, management will be adapted on a case-by-case basis (expert opinion). In the event of fetal death occurring in a twin pregnancy, it is suggested that the surviving twin be evaluated as soon as the diagnosis of fetal death is made. In the case of dichorionic pregnancy, it is suggested to offer ultrasound monitoring on a monthly basis. It is suggested not to deliver prematurely following fetal death of a twin. If fetal death occurs in a monochorionic twin pregnancy, it is suggested to contact the referral competence center, in order to urgently look for signs of acute fetal anemia on ultrasound in the surviving twin, and to carry out weekly ultrasound monitoring for the first month. It is suggested not to induce birth immediately.

Prognosis of remaining fetus in twin pregnancy after demise of one fetus according to its location

BACKGROUND

To investigate the prognosis of the remaining fetus in twin pregnancy after experiencing one fetal demise in the first trimester according to the location of the demised fetus.

METHODS

This was a retrospective study of twin pregnancies with one fetal demise after the first trimester (14 weeks of gestation) delivered between September 2004 and September 2022. The study population was divided into two groups based on the location of the demised fetus as determined by the last recorded ultrasonography results: Group 1 included twin pregnancies where the presenting fetus was demised (n = 36) and Group 2 included twin pregnancies where the non-presenting fetus was demised (n = 44). The obstetric and neonatal outcomes were also reviewed.

RESULTS

A total of 80 pregnant women were included. The median gestational age for the diagnosis of fetal demise was 24.1 weeks. The gestational age of the demised fetus was not different between Groups 1 and 2; however, the gestational age of the remaining fetus at delivery was significantly earlier in Group 1 than it was in Group 2 (33.8 vs. 37.3 weeks, P = .004). The rate of preterm birth before 28 weeks was almost five times higher in Group 1 than in Group 2 (22.2% vs. 4.5%, P = .037). Regression analysis demonstrated significant differences between Groups 1 and 2. Respiratory distress syndrome, bronchopulmonary dysplasia, patent ductus arteriosus, retinopathy of prematurity, and jaundice were more common in Group 1 than in Group 2; however, the association was not significant after adjusting for gestational age at delivery.

CONCLUSIONS

When the presenting fetus is demised in a twin pregnancy, the remaining fetus tends to be delivered earlier than when the non-presenting fetus is demised.

Co-Twin Prognosis After Single Intrauterine Fetal Death at a Tertiary Care Hospital in India: A Retrospective Observational Study

INTRODUCTION

Twin pregnancy is associated with an increased risk of perinatal morbidity. Besides, if intrauterine death of a single twin occurs, it increases the morbidity of the surviving co-twin perinatally and postnatally.

AIM

 The objective of this study was to determine the incidence of single intrauterine fetal death (SIUFD) in a twin pregnancy and fetal outcome defined in dimensions according to the complications in the surviving co-twin.

MATERIAL AND METHODS

Data on twin pregnancies were collected retrospectively for a period of five years (from 2015 to 2019) from the labour room records of the Central Records Department (CRD) at the Postgraduate Institute of Medical Education and Research, Chandigarh, India. Cases with SIUFD were studied individually and neonatal follow-up was taken post delivery for up to three to eight years. Inclusion criteria were SIUFD in twin pregnancies after 14 weeks gestation, chorionicity pre-defined by early trimester ultrasonography. Exclusion criteria were higher-order pregnancy and monoamniotic twins.

RESULTS

A total of 1246 (4.273%) twin deliveries were conducted in the study period. Of these, 107 (8.587%) pregnancies had SIUFD with co-twin surviving in utero. Among these, 77 (72%) were dichorionic diamniotic (DCDA) twin pregnancies and 30 (28%) were monochorionic diamniotic (MCDA) twin pregnancies. The incidence of SIUFD was 8.5%. Preterm birth was the most common complication observed in our study and was found in 53.5% and 58.3% of participants in DCDA and MCDA twins, respectively. Early neonatal death (within 24 hours of life) of the surviving twin was found in 29.2% monochorionic twins with SIUFD. SIUFD at < 28 weeks gestation led to a greater number of early neonatal deaths of surviving twins. The incidence of neurodevelopmental disorders (cerebral palsy, developmental delay, epilepsy) in our population after birth was 7.5% (n=93).

CONCLUSION

Twin pregnancies with SIUFD have an increased incidence of preterm labour, increased neonatal death of the surviving twin, and neurodevelopmental disorders (cerebral palsy, developmental delay, epilepsy). Monochorionicity and SIUFD at <28 weeks gestation are associated with increased neonatal deaths in co-twin. The Incidence of neurodevelopmental disorders is not directly associated with chorionicity, but developmental delay is more profoundly seen in the monochorionic group.

The effect of chorionicity on maternal and neonatal outcomes in triplet pregnancies

OBJECTIVE

Triplet gestations are associated with increased maternal, fetal, and neonatal complications particularly early and extreme preterm delivery. Identifying and interrupting the preterm delivery cascade could prevent the fetal, neonatal, and long-term childhood complications. The shared circulation and placental vascular anastomosis are responsible for the occurrence of twin-to-twin transfusion syndrome, selective fetal growth restriction as well as the higher risk of morbidity and mortality observed in mono and dichorionic compared to trichorionic triplet gestations. Thus, the aim of this study was to determine the effect of chorionicity on maternal, fetal, and neonatal outcomes of triplet pregnancies as it has not been fully ascertained.

STUDY DESIGN

A retrospective population-based cohort study of 125 parturient with triplets' pregnancy who delivered at a single tertiary hospital.

RESULTS

98 trichorionic and 27 dichorionic gestations were included. Maternal demographic and obstetric characteristics as well as pregnancy and postpartum complications were similar in the two study groups. The median gestational age at delivery was lower among dichorionic than trichorionic triplet gestations (median 31 vs 33 weeks, p < 0.046). Early (<32 weeks) and extreme preterm delivery (<28 weeks) were more prevalent in the dichorionic than the trichorionic group (early - 56 % vs 34 %, p < 0.038; extreme - 33.3 % vs 8 %, p < 0.002). We found no difference in fetal or newborns' complications and characteristics between the groups. However, the rate of neonatal death was significantly higher in the dichorionic compared to trichorionic triplet gestations (22 % vs 7 %, p < 0.038). A multivariate logistic regression model to determine the variables that contribute to early preterm delivery in triplet gestations showed that women who experienced a past preterm delivery had an independently higher risk for early preterm delivery in the triplet gestation (adj. OR 5.91, 95 % CI 1.16-30.03). Neither maternal age nor chorionicity were found to be independent risk factors for early preterm delivery.

CONCLUSIONS

Dichorionic triplet gestations exhibit a higher rate of early (<32 weeks) and extreme (<28 weeks) preterm delivery and are more prone to neonatal death compared to trichorionic gestations. Past preterm delivery is an independent risk factor for early preterm delivery in a triplet gestation.

Pregnancy and obstetric outcomes of dichorionic triamniotic triplet pregnancies with selective foetal reduction after assisted reproductive technology

BACKGROUND

It is generally beneficial and recommended that dichorionic triamniotic (DCTA) triplet pregnancies be reduced to monochorionic (MC) twin or singleton pregnancies after assisted reproductive technology (ART). However, some infertile couples still have a firm desire to retain twins. For this reason, the best foetal reduction strategies need to be available for infertile couples and clinicians. Given that data on the elective reduction of DCTA triplet pregnancies to twin pregnancies are scarce, we investigated the outcomes of elective reduction of DCTA triplet pregnancies through the retrospective analysis of previous data.

METHOD

Patients with DCTA triplet pregnancies who underwent elective foetal reduction between January 2012 and June 2020 were recruited. A total of 67 eligible patients with DCTA triplet pregnancies were divided into two groups: a DCTA-to-dichorionic diamniotic (DCDA) twin group (n = 38) and a DCTA-to-monochorionic diamniotic (MCDA) twin group (n = 29); the basic clinical data of the two groups were collected for comparison.

RESULTS

Compared with the DCDA-to-MCDA twin group, the DCTA-to-DCDA twin group had lower rates of complete miscarriage (7.89% versus 31.03%, p = 0.014), early complete miscarriage (5.26% versus 24.14%, p = 0.034), late preterm birth (25.71% versus 65.00%, p = 0.009) and very low birth weight (0 versus 11.11%, p = 0.025). In addition, the DCTA-to-DCDA twin group had higher rates of full-term delivery (65.71% versus 25.00%, p = 0.005), survival (92.11% versus 68.97%, p = 0.023), and taking the babies home (92.11% versus 68.97%, p = 0.023) than did the DCTA-to-MCDA twin group. In terms of neonatal outcomes, a significantly greater gestational age (38.06 ± 2.39 versus 36.28 ± 2.30, p = 0.009), average birth weight (3020.77 ± 497.33 versus 2401.39 ± 570.48, p < 0.001), weight of twins (2746.47 ± 339.64 versus 2251.56 ± 391.26, p < 0.001), weight of the larger neonate (2832.94 ± 320.58 versus 2376.25 ± 349.95, p < 0.001) and weight of the smaller neonate (2660.00 ± 345.34 versus 2126.88 ± 400.93, p < 0.001) was observed in the DCTA-to-DCDA twin group compared to the DCTA-to-MCDA twin group.

CONCLUSION

The DCTA-to-DCDA twin group had better pregnancy and neonatal outcomes than the DCTA-to-MCDA twin group. This reduction approach may be beneficial for patients with dichorionic triamniotic triplet pregnancies who have a strong desire to have DCDA twins.

Clinical outcomes of fetal selective reduction in dichorionic triplet pregnancies

BACKGROUND

It is recommended to reduce triplet pregnancy containing monochorionic (MC) twins to singleton. Given that some couples with infertility are eager to retain twins, better strategy is needed to avoid obstetrical risks and satisfy their strong wish. This retrospective observational study aimed to investigate the outcomes of triplet pregnancy reduction.

METHODS

Subjects with triplet pregnancies who underwent selective reduction between 2016 and 2019 at our hospital were enrolled. A total of 66 subjects with dichorionic triplet (DCT) with MC twins and an MC singleton were divided into two groups: group A (N = 38), reduced to dichorionic diamniotic (DCDA) twins; group B (N = 28), reduced to MC diamniotic (MCDA) twins. Obstetrical and perinatal outcomes were compared between groups.

RESULTS

Group A had significantly lower rates of early miscarriage (0% vs 14.3%, p = 0.028), cesarean section (81.6% vs 100%, p = 0.041), and late premature delivery (21.1% vs 45.4%, p = 0.047) than group B. Significantly higher rates of full-term delivery (71% vs 36.4%, p = 0.009) and take-home baby (100% vs 78.6%, p = 0.004), and higher gestational age at delivery (median: 38 [36.9, 39.0] vs 35.8 [34.4, 37.0] weeks, p < 0.001), total neonatal weight (2899.7 ± 647.6 vs 2354.4 ± 651.8 g, p < 0.001), weight of twins (2550 vs 2350 g, p = 0.039), and weight of larger neonate in twins (2790 vs 2500 g, p = 0.045) were observed in group A compared to group B.

CONCLUSION

DCT reduced to DCDA twins confers better pregnancy outcomes than into MCDA twins. This might benefit for triplet pregnancy subjects who strongly want to retain fraternal twins.

Risk factors for preterm birth: an umbrella review of meta-analyses of observational studies

BACKGROUND

Preterm birth defined as delivery before 37 gestational weeks is a leading cause of neonatal and infant morbidity and mortality. The aim of this study is to summarize the evidence from meta-analyses of observational studies on risk factors associated with PTB, evaluate whether there are indications of biases in this literature, and identify which of the previously reported associations are supported by robust evidence.

METHODS

We searched PubMed and Scopus until February 2021, in order to identify meta-analyses examining associations between risk factors and PTB. For each meta-analysis, we estimated the summary effect size, the 95% confidence interval, the 95% prediction interval, the between-study heterogeneity, evidence of small-study effects, and evidence of excess-significance bias. Evidence was graded as robust, highly suggestive, suggestive, and weak.

RESULTS

Eighty-five eligible meta-analyses were identified, which included 1480 primary studies providing data on 166 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections, and vaccines. Ninety-nine (59.3%) associations were significant at P < 0.05, while 41 (24.7%) were significant at P < 10-6. Ninety-one (54.8%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 37 (22.3%) and 12 (7.2%) associations, respectively. We evaluated all associations according to prespecified criteria. Seven risk factors provided robust evidence: amphetamine exposure, isolated single umbilical artery, maternal personality disorder, sleep-disordered breathing (SDB), prior induced termination of pregnancy with vacuum aspiration (I-TOP with VA), low gestational weight gain (GWG), and interpregnancy interval (IPI) following miscarriage < 6 months.

CONCLUSIONS

The results from the synthesis of observational studies suggest that seven risk factors for PTB are supported by robust evidence. Routine screening for sleep quality and mental health is currently lacking from prenatal visits and should be introduced. This assessment can promote the development and training of prediction models using robust risk factors that could improve risk stratification and guide cost-effective preventive strategies.

TRIAL REGISTRATION

PROSPERO 2021 CRD42021227296.

Fetoscopic demonstration of feto-fetal hemorrhage before actual demise of a monochorionic twin, successful antenatal treatment, and narrative review of the literature

Feto-fetal hemorrhage (FFH) through placental vascular anastomoses is believed to be responsible for the death or damage of a "second twin" after the demise of a "first twin (co-twin)" in monochorionic twin pregnancies. However, the timing of FFH has been difficult to determine. The resulting anemia in the surviving twin can be suspected by the finding of an elevated middle cerebral artery peak-systolic velocity (MCA-PSV), but this elevation may lag for at least 4 h after the demise of the first twin. Knowledge of the timing of FFH may have important clinical implications, as it may dictate if and when attempts to prevent death or damage to the second twin by delivery or intrauterine fetal transfusion would be warranted. We present a case that supports the notion that FFH occurs before the actual demise of the first twin. A review of the literature was also conducted.

Twin Gestation With Spontaneous Reduction To Singleton

Twin gestations are at increased risk of single intrauterine fetal death. A first-trimester loss is a common complication in twin gestations. The rate of co-twin morbidity and mortality is higher when a single demise occurs in the second and third trimesters. Monochorionicity strongly influences the prognosis for the surviving co-twin. Fetal ultrasound combined with MRI may be able to help predict neurological injury to the surviving co-twin. The rate of co-twin demise decreases with advancing gestation. After single intrauterine fetal demise, monochorionic gestations should be delivered by 34 weeks and dichorionic by 36 to 37 weeks gestation.

Directive clinique no 440 : Prise en charge de la grossesse gémellaire monochoriale

OBJECTIF

Cette directive clinique passe en revue les données probantes sur la prise en charge de la grossesse gémellaire monochoriale normale et compliquée.

POPULATION CIBLE

Les femmes menant une grossesse gémellaire ou multiple de haut rang. BéNéFICES, RISQUES ET COûTS: L'application des recommandations de cette directive devrait améliorer la prise en charge des grossesses gémellaires (ou multiples de haut rang) monochoriales compliquées et non compliquées. Ces recommandations aideront les fournisseurs de soins à surveiller adéquatement les grossesses gémellaires monochoriales ainsi qu'à détecter et prendre en charge rapidement les complications associées de façon optimale afin de réduire les risques de morbidité et mortalité périnatales. Ces recommandations impliquent une surveillance échographique plus fréquente en cas de grossesse monochoriale qu'en cas de grossesse bichoriale. DONNéES PROBANTES: La littérature publiée a été colligée par des recherches dans les bases de données PubMed et Cochrane Library au moyen de termes MeSH pertinents (Twins, Monozygotic; Ultrasonography, Prenatal; Placenta; Fetofetal Transfusion; Fetal Death; Fetal Growth Retardation). Les résultats ont été restreints aux revues systématiques, aux essais cliniques randomisés et aux études observationnelles. Aucune date limite n'a été appliquée, mais les résultats ont été limités aux contenus en anglais ou en français. MéTHODES DE VALIDATION: Les auteurs principaux ont rédigé le contenu et les recommandations et ils se sont entendus sur ces derniers. Le conseil d'administration de la SOGC a approuvé la version définitive aux fins de publication. Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations Assessment, Development and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Spécialistes en médecine fœto-maternelle, obstétriciens, radiologues, échographistes, médecins de famille, infirmières, sages-femmes, résidents et autres fournisseurs de soins de santé qui s'occupent de femmes menant une grossesse gémellaire ou multiple de haut rang. RéSUMé POUR TWITTER: Directive canadienne (SOGC) pour le diagnostic, la surveillance échographique et la prise en charge des complications de la grossesse gémellaire monochoriale (p. ex., STT, TAPS, retard de croissance sélectif, cojumeau acardiaque, monoamnionicité et mort d'un jumeau). DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Guideline No. 440: Management of Monochorionic Twin Pregnancies

OBJECTIVE

This guideline reviews the evidence-based management of normal and complicated monochorionic twin pregnancies.

TARGET POPULATION

Women with monochorionic twin or higher order multiple pregnancies.

BENEFITS, HARMS, AND COSTS

Implementation of these recommendations should improve the management of both complicated and uncomplicated monochorionic (and higher order multiple) twin pregnancies. They will help users monitor monochorionic twin pregnancies appropriately and identify and manage monochorionic twin complications optimally in a timely manner, thereby reducing perinatal morbidity and mortality. These recommendations entail more frequent ultrasound monitoring of monochorionic twins compared to dichorionic twins.

EVIDENCE

Published literature was retrieved through searches of PubMed and the Cochrane Library using appropriate MeSH headings (Twins, Monozygotic; Ultrasonography, Prenatal; Placenta; Fetofetal Transfusion; Fetal Death; Fetal Growth Retardation). Results were restricted to systematic reviews, randomized controlled clinical trials, and observational studies. There were no date limits, but results were limited to English or French language materials.

VALIDATION METHODS

The content and recommendations were drafted and agreed upon by the principal authors. The Board of the SOGC approved the final draft for publication. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

Maternal-fetal medicine specialists, obstetricians, radiologists, sonographers, family physicians, nurses, midwives, residents, and other health care providers who care for women with monochorionic twin or higher order multiple pregnancies.

TWEETABLE ABSTRACT

Canadian (SOGC) guidelines for the diagnosis, ultrasound surveillance and management of monochorionic twin pregnancy complications, including TTTS, TAPS, sFGR (sIUGR), acardiac (TRAP), monoamniotic twins and intrauterine death of one MC twin.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Management of the smaller twin with impending compromise in twin pregnancies complicated by selective fetal growth restriction: a questionnaire-based study of clinical practice patterns

BACKGROUND

In twin pregnancies complicated by selective fetal growth restriction (sFGR), if the smaller twin is in the state of impending intra-uterine death (IUD), immediate delivery will reduce the risk of IUD of the smaller twin while exposing the larger twin to iatrogenic preterm birth (PTB). Therefore, the management options would either be to maintain pregnancy for the maturation of the larger twin despite the risk of IUD of the smaller twin or immediate delivery to prevent IUD of the smaller twin. However, the optimal gestational age of management transition from maintaining pregnancy to immediate delivery has not been established. The objective of this study was to evaluate the physician's perspective on the optimal timing of immediate delivery in twin pregnancies complicated by sFGR.

METHODS

An online cross-sectional survey was performed with obstetricians and gynecologists (OBGYN) in South Korea. The questionnaire asked the following: (1) whether participants would maintain or immediately deliver a twin pregnancy complicated by sFGR with signs of impending IUD of the smaller twin; (2) the optimal gestational age of management transition from maintaining pregnancy to immediate delivery in a twin pregnancy with impending IUD of the smaller twin; and (3) the limit of viability and intact survival in general preterm neonates.

RESULTS

A total of 156 OBGYN answered the questionnaires. In a clinical scenario of dichorionic (DC) twin pregnancy complicated by sFGR with signs of impending IUD of the smaller twin, 57.1% of the participants answered that they would immediately deliver the twin pregnancy. However, 90.4% answered that they would immediately deliver the pregnancy in the same scenario for monochorionic (MC) twin pregnancy. The participants designated 30 weeks for DC twin and 28 weeks for MC twin pregnancies as the optimal gestational age of management transition from maintaining pregnancy to immediate delivery. The participants regarded 24 weeks as the limit of viability and 30 weeks as the limit of intact survival in general preterm neonates. The optimal gestational age of management transition for DC twin pregnancy was correlated with the limit of intact survival in general preterm neonates (p < 0.001), but not with the limit of viability. However, the optimal gestational age of management transition for MC twin pregnancy was associated with both the limit of intact survival (p = 0.012) and viability with marginal significance (p = 0.062).

CONCLUSIONS

Participants preferred to immediately deliver twin pregnancies complicated by sFGR with impending IUD of the smaller twin at the limit of intact survival (30 weeks) for DC twin pregnancies and at the midway between the limit of intact survival and viability (28 weeks) for MC twin pregnancies. More research is needed to establish guidelines regarding the optimal delivery timing for twin pregnancies complicated by sFGR.

Risk factors for preterm labor: An Umbrella Review of meta-analyses of observational studies

Preterm birth defined as delivery before 37 gestational weeks, is a leading cause of neonatal and infant morbidity and mortality. Understanding its multifactorial nature may improve prediction, prevention and the clinical management. We performed an umbrella review to summarize the evidence from meta-analyses of observational studies on risks factors associated with PTB, evaluate whether there are indications of biases in this literature and identify which of the previously reported associations are supported by robust evidence. We included 1511 primary studies providing data on 170 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections and vaccines. Only seven risk factors provided robust evidence. The results from synthesis of observational studies suggests that sleep quality and mental health, risk factors with robust evidence should be routinely screened in clinical practice, should be tested in large randomized trial. Identification of risk factors with robust evidence will promote the development and training of prediction models that could improve public health, in a way that offers new perspectives in health professionals.

Outcome of Twin Pregnancies Complicated by a Single Intrauterine Death

Objective

Single intrauterine fetal death (sIUFD) occurs in approximately 6% of twin pregnancies. If it occurs in the second and third trimesters, it places the co-twin at substantial risk, including that of preterm delivery and associated comorbidities of prematurity or neonatal death. The aim of this present study was to determine the outcome of surviving co-twins following spontaneous single intrauterine fetal death.

Methods

This is a retrospective, observational, cohort study that included all twin pregnancies delivered between January 2015 to December 2019 with a gestational age of 24 weeks or more. Maternal data included were: age, medical illnesses, conceivable methods, chorionicity, and complications during pregnancy. Gestational age of intrauterine fetal demise, gestational age of the surviving twin delivery, mode of delivery, and medications used during pregnancy were also recorded. Neonatal data included: gestational age, gender, birth weight, Apgar score, and complications of prematurity.

Results

Twenty-two pregnancies were found to be complicated by sIUFD and included in the present study (group 1), compared to 26 twins with no sIUFD (group 2). The incidence of sIUFD in twin pregnancies after 20 weeks of pregnancy was 4.4%. The gestational age (weeks) in group 1 was 34.5 (29-39) and in group 2 was 32 (26-38). The frequency of preterm delivery 81.8% in group 1 (59% monochorionic) and 69.2% (100% dichorionic) in group 2. No significant statistical differences were found between the two groups in complications of prematurity.

Conclusions

We conclude that delaying delivery in twin pregnancies complicated by single intrauterine demise with regular follow-up may lead to delivering infants with fewer complications of prematurity.

Correlation analysis of adverse outcomes for the selective reduction of twin pregnancies

BACKGROUND

Due to the extensive development of assisted reproductive technology, the number of twin pregnancies has increased significantly over recent decades. Twin pregnancy is the most representative type of multiple pregnancies and is associated with high infant morbidity and mortality. Perinatal complications of twin pregnancy are also markedly increased compared with those of single pregnancy. Transabdominal selective reduction (SR) is a remedial intervention. This study aimed to research the adverse outcomes of transabdominal selective reduction of twin pregnancy and the correlation between the reduction week and pregnancy outcomes.

OBJECTIVE

The purpose of this study was to examine the adverse outcomes of the transabdominal selective reduction of twin pregnancy and the correlation between the reduction week and pregnancy outcomes.

METHODS

A retrospective cohort study of the transabdominal reduction of twin pregnancy was conducted in a single prenatal diagnosis medical centre from September 2012 to October 2020. According to chorionicity, women with twin pregnancies were divided into 2 groups: dichorionic (DC) twin pregnancies and monochorionic (MC) twin pregnancies. Women with DC twin pregnancies underwent potassium chloride reduction, and those with MC twin pregnancies underwent radiofrequency ablation (RFA). The reduction indications included pregnancy complications, foetal abnormalities, and maternal factors. The perinatal outcomes of different chorionic twins after reduction were analysed. Each foetus with an adverse outcome was included. The relative relationship between the reduction weeks and delivery weeks of twins was examined by correlation analysis.

RESULTS

A total of 161 women were included in this study. A total of 112 women had DC twin pregnancies, and 49 women had MC twin pregnancies. Preterm delivery rates were significantly higher in the MC twin reduction group than in the DC twin reduction group prior to 37 weeks (53.1% vs. 29.5%, P = 0.004). The mean gestational age at delivery of the foetuses in the DC twin group that underwent SR was significantly older than that of those in the MC twin group that underwent SR (36.9 ± 4.0 vs. 33.5 ± 6.6 weeks, P = 0.001). The number of DC twins that underwent SR and were delivered after 37 weeks was obviously greater than that of the MC twins that underwent SR (70.5% vs. 46.9%, P = 0.004). The foetal survival rate was 95.5% in the DC twin reduction group and 77.6% in the MC twin reduction group. If the indication of TTTS was not included, there was no significant difference in the foetal survival rate of the DC and MC twin reduction groups (95.5% vs. 86.2%, P = 0.160). Cotwin death 1 week after reduction was greater in the MC group (6.1% vs. 0%, P = 0.027). Compared to other indications, this finding indicated that a significantly lower proportion of women remained undelivered after selective reduction with the indication of TTTS. There was a significant negative correlation between the reduction weeks and delivery weeks of the two groups (P < 0.01), and the best opportunity for reduction was before 22 weeks of gestation.

CONCLUSION

These findings highlighted an obviously negative correlation between the reduction week and delivery week. The transabdominal selective reduction of twin pregnancy should be considered for a lower rate of miscarriage or premature delivery if the reduction week takes place earlier in pregnancy. The rate of preterm delivery was the lowest when transabdominal selective reduction was completed before 22 weeks of gestation. Compared with other RFA indications, a higher rate of premature delivery was shown for MC twins with a reduction indication of TTTS. TTTS with sIUGR might be one of the reasons for the adverse outcomes of reduction for MC twin pregnancy.

Selective reduction in complicated monochorionic pregnancies: a systematic review and meta-analysis of different techniques

OBJECTIVE

This systematic review and meta-analysis aimed to compare the perinatal outcomes of complicated monochorionic pregnancies after selective reduction by radiofrequency ablation, bipolar cord coagulation, and interstitial laser.

DATA SOURCES

We searched PubMed, Scopus, and Web of Science, from the inception of the database up to April 26, 2021.

STUDY ELIGIBILITY CRITERIA

Studies comparing at least 2 selective reduction techniques among complicated monochorionic pregnancies and presenting data on perinatal outcomes, including gestational age at procedure, gestational age at delivery, procedure to delivery interval, preterm premature rupture of membranes, preterm birth, survival rate, and birthweight, were eligible.

METHODS

The random-effects model was used to pool the mean differences or odds ratios and corresponding 95% confidence intervals. Heterogeneity was assessed using the I² value.

RESULTS

A total of 10 studies with 734 cases of fetal reduction met the inclusion criteria, of which 9 studies with 674 fetuses were eligible for quantitative synthesis. In 8 studies that compared radiofrequency ablation with bipolar cord coagulation, radiofrequency ablation was associated with increased procedure to delivery interval (days) (mean difference, 13.42; 95% confidence interval, 1.90-24.94; P=.02; I²=0.0%), decreased preterm birth (odds ratio, 0.50; 95% confidence interval, 0.29-0.85; P=.01; I²=3.0%), and decreased preterm premature rupture of membranes (odds ratio, 0.45; 95% confidence interval, 0.27-0.73; P=.001; I²=0.0%). Radiofrequency ablation and bipolar cord coagulation had comparable survival rates (odds ratio, 0.85; 95% confidence interval, 0.54-1.35; P=.49; I²=0.0%). In 3 studies that compared radiofrequency ablation with interstitial laser, there was no significant difference in gestational age at delivery (P=.07) or survival (P=.15). In 3 studies that compared bipolar cord coagulation with interstitial laser, bipolar cord coagulation was associated with a higher survival rate (odds ratio, 3.21; 95% confidence interval, 1.13-9.10; P=.03; I²=0.0%), but the gestational age at delivery was comparable between groups (P=.16).

CONCLUSION

This study demonstrated that radiofrequency ablation has a greater procedure to delivery interval and decreased preterm premature rupture of membranes and preterm birth than bipolar cord coagulation. Although there was no difference in gestational age at delivery for either bipolar cord coagulation, radiofrequency ablation, or interstitial laser, survival was higher with bipolar cord coagulation than with interstitial laser.

Fetoscopic Laser Ablation for the Selective Fetal Reduction in Twin-Twin Transfusion Syndrome Stage II-IV: The Experience of a New Fetal Medicine Center

Objective

To evaluate the surgery outcomes of fetoscopic laser ablation (FLA) for selective umbilical cord in treating twin-twin transfusion syndrome (TTTS) with special conditions and neonatal outcomes post-operation.

Methods

A prospective study, 21 monochorionic diamniotic (MCDA) twins diagnosed with TTTS stage II–IV according to Quintero classification from 16 to 26 weeks of gestation, among that, 12 cases of TTTS stage II with selective intrauterine growth restriction (sIUGR), 6 cases of TTTS stage II with proximate cord insertions, 3 cases of TTTS stage IV underwent fetoscopic laser ablation for the selective fetal reduction at Hanoi Obstetrics and Gynecology Hospital from September 2019 to July 2021. Complications and surgical outcomes were noted. Prenatal care was carried out every 2 weeks post operation until birth. Newborn neurologic complications were assessed at birth, three months, and six months after birth using Denver II test and magnetic resonance imaging (MRI).

Results

The mean gestational age at operation was 20.30 weeks. The average operation duration was 39.52 minutes. No complications of operation, such as bleeding or infection, were recorded. The mean gestational age at birth was 34.70 ± 4.33 weeks, with a mean duration of 12.97 ± 6.87 weeks between intervention and delivery. The survival rate of newborns after the operation was 90.48%. There were two stillbirths (9.52%) within seven days after the operation. No short-term neurological complications have been reported with follow-up of the newborn to 6 months after birth.

Conclusion

Our study showed that fetoscopic laser ablation of selected fetal reduction surgery for treatment of special conditions of TTTS had no complications of operation, high neonatal survival result (90.48%), no short-term neurological complications. This should be considered for TTTS in cases of indication.

Comprehensive Metabolomic Profiling of Cord Blood and Placental Tissue in Surviving Monochorionic Twins Complicated by Twin-Twin Transfusion Syndrome With or Without Fetoscopic Laser Coagulation Surgery: A Retrospective Cohort Study

Objectives: To investigate metabolomic perturbations caused by twin-twin transfusion syndrome, metabolic changes associated with fetoscopic laser coagulation in both placental tissue and cord plasma, and to investigate differential metabolites pertinent to varying fetal outcomes, including hemodynamic status, birth weight, and cardiac function, of live-born babies.

Methods: Placental tissue and cord plasma samples from normal term or uncomplicated preterm-born monochorionic twins and those complicated by twin-twin transfusion syndrome treated with or without fetoscopic laser coagulation were analyzed by high-performance liquid chromatography metabolomic profiling. Sixteen comparisons of different co-twin groups were performed. Partial least squares–discriminant analysis, metabolic pathway analysis, biomarker analysis, and Spearman’s correlation analysis were conducted based on differential metabolites used to determine potential biomarkers in different comparisons and metabolites that are pertinent to neonatal birth weight and left ventricular ejection fraction.

Results: These metabolomic investigations showed that the cord plasma metabolome has a better performance in discriminating fetuses among different hemodynamic groups than placental tissue. The metabolic alteration of twin-twin transfusion syndrome in these two types of samples centers on fatty acid and lipid metabolism. The fetoscopic laser coagulation procedure improves the metabolomic change brought by this syndrome, making the metabolomes of the treated group less distinguishable from those of the control and preterm birth groups. Certain compounds, especially lipids and lipid-like molecules, are noted to be potential biomarkers of this morbid disease and pertinent to neonatal birth weight and ejection fraction.

Conclusions: Fetoscopic laser coagulation can ameliorate the metabolomic alteration caused by twin-twin transfusion syndrome in placental tissue and cord plasma, which are involved mainly in fatty acid and lipid-like molecule metabolism. Certain lipids and lipid-like molecules are helpful in differentiating co-twins of different hemodynamic statuses and are significantly correlated with neonatal birth weight or ejection fraction.

Maternal, Perinatal and Neonatal Outcomes of Triplet Pregnancies According to Chorionicity: A Systematic Review of the Literature and Meta-Analysis

Triplet pregnancies are rare events that affect approximately 93 in 100,000 deliveries in the world, especially due to the increased use of assisted reproductive techniques and older maternal age. Triplet pregnancies are associated with a higher risk of fetal and maternal morbidity and mortality compared to twins and singletons. Chorionicity has been proposed as a major determinant of perinatal and maternal outcomes in triplet pregnancies, although further evidence is needed to clarify the extent and real influence of this factor. Thus, the aim of this study was to conduct a systematic review of the literature and a meta-analysis of the maternal and perinatal outcomes of triplet pregnancies, evaluating how chorionicity may influence these results. A total of 46 studies with 43,653 triplet pregnancies and 128,145 live births were included. Among the main results of our study, we found a broad spectrum of fetal and maternal complications, especially in the group of monochorionic and dichorionic pregnancies. Risk of admission to NICU, respiratory distress, sepsis, necrotizing enterocolitis, perinatal and intrauterine mortality were all found to be higher in non-TCTA pregnancies than in TCTA pregnancies. To date, our meta-analysis includes the largest population sample and number of studies conducted in this field, evaluating a wide variety of outcome measures. The heterogeneity and retrospective design of the studies included in our research represent the main limitations of this review. More evidence is needed to fully assess outcome measures that could not be studied in this review due to scarcity of publications or insufficient sample size.

Third Trimester Structural and Diffusion Brain Imaging after Single Intrauterine Fetal Death in Monochorionic Twins: MRI-Based Cohort Study

BACKGROUND AND PURPOSE

Single intrauterine fetal death increases the risk of antenatal brain lesions in the surviving twin. We evaluated the prevalence of structural brain lesions, biometry, and diffusivity on routine third trimester MR imaging performed following single intrauterine fetal death.

MATERIALS AND METHODS

In a retrospective MR imaging-based cohort study, we compared 29 monochorionic twins complicated with single intrauterine fetal death (14 following laser ablation treatment for twin-to-twin transfusion syndrome, 8 following selective fetal reduction, and 7 spontaneous) with 2 control cohorts (49 singleton fetuses and 28 uncomplicated twin fetuses). All fetuses in the single intrauterine fetal death group underwent fetal brain MR imaging as a routine third trimester evaluation. Structural brain lesions were analyzed. Cerebral biometry and diffusivity were measured and compared.

RESULTS

Brain lesions consistent with the evolution of prior ischemic injury were found in 1 of 29 fetuses, not detected by ultrasound. No acute brain infarction, hemorrhage, or cortical abnormalities were found. Supratentorial biometric measurements in the single intrauterine fetal death group were significantly smaller than those in the singleton group, but not significantly different from those in the uncomplicated twin group. There were no significant differences in ADC values of the cerebral hemispheres, basal ganglia, and pons between the single intrauterine fetal death group and either control group.

CONCLUSIONS

Although smaller brain biometry was found, normal diffusivity in surviving twins suggests normal parenchymal microstructure. The rate of cerebral structural injury was relatively low in our cohort, arguing against the routine use of fetal brain MR imaging in twin pregnancies complicated with single intrauterine fetal death. Larger prospective studies are necessary to guide appropriate surveillance protocol and parental counseling in twin pregnancies complicated by single intrauterine fetal death.

Outcomes of laser surgery for stage I twin-twin transfusion syndrome

OBJECTIVE

A recent randomized controlled trial (RCT) demonstrated no difference in 6 month survival in expectantly managed stage I twin-twin transfusion syndrome (TTTS) patients and those undergoing immediate laser surgery. We aimed to describe outcomes following immediate laser surgery at a single fetal surgery center.

METHODS

A retrospective study of monochorionic diamniotic twins diagnosed with stage I TTTS who underwent laser surgery between 16 and 26 gestational weeks from 2006 to 2019. The primary outcome was 6 month survivorship. Intact survival was also assessed. Secondarily, outcomes were compared to the RCT expectant management group.

RESULTS

Of 126 consecutive stage I TTTS patients, 114 (90.5%) met inclusion criteria. Median (range) gestational age at delivery was 34.1 (20.6-39.4) weeks. At 6 months, the proportion of patients with at-least-one survivor in the single-center-laser cohort was 97.4%, with 88.6% dual survivorship. Neurological morbidity outcomes were available in 110 pregnancies (220 fetuses). Severe neurological morbidity occurred in 2.7% (6/220), and 6 month survival without severe neurological morbidity was 90.0%. Outcomes compared favorably with the RCT expectant management group.

CONCLUSIONS

Given favorable survival and neurological outcomes, laser surgery is a reasonable treatment option for stage I TTTS at experienced fetal surgery centers. Further study is warranted to optimize treatment strategies.

Predicting Adverse Outcomes in Monochorionic-Diamniotic Twins: The Role of Intertwin Discrepancy in Middle Cerebral Artery Doppler Measurements and the Cerebroplacental Ratio

OBJECTIVE

This study was aimed to evaluate the role of intertwin discrepancy in middle cerebral artery peak systolic velocity (MCA-PSV) and cerebroplacental ratio (CPR) for the prediction of adverse outcomes in monochorionic-diamniotic (MCDA) twin pregnancies.

STUDY DESIGN

A retrospective cohort study of MCDA pregnancies that underwent ultrasound surveillance at a perinatal referral center from 2007 to 2017. Intertwin MCA-PSV discrepancy (MCA-Δ_PSV-MoM) was defined as the absolute difference of MCA-PSV multiple of the median (MoM) for gestational age between twins. Intertwin CPR discrepancy (CPR-Δ) was defined as the absolute difference of CPR between twins. The maximum MCA-Δ_PSV-MoM and CPR-Δ before and after 26 weeks of gestation were assessed as predictors of pregnancy and neonatal outcomes through simple logistic regression models and Pearson's correlation coefficients. Receiver operating characteristic (ROC) curves were generated to determine the predictive value of maximum MCA-Δ_PSV-MoM and CPR-Δ.

RESULTS

A total of 143 MCDA pregnancies met inclusion criteria. There was a significant association between MCA-Δ_PSV-MoM at <26 weeks and the development of twin anemia-polycythemia sequence (TAPS; p = 0.007), intrauterine fetal demise (IUFD; p = 0.009), and neonatal intensive care unit (NICU) admission (p < 0.05). MCA-Δ_PSV-MoM at ≥26 weeks was associated with the development of TAPS (p < 0.001). CPR-Δ at <26 weeks was associated with the development of twin-twin transfusion syndrome (TTTS; p = 0.03) and NICU admission (p = 0.02). MCA-Δ_PSV-MoM at ≥26 weeks was highly predictive of TAPS (area under curve [AUC] = 0.92). A cut-off of 0.44 would identify TAPS with 100% sensitivity and 73% specificity.

CONCLUSION

In MCDA pregnancies, intertwin MCA and CPR discrepancies are associated with adverse pregnancy and neonatal outcomes, including TAPS, TTTS, IUFD, and NICU admission. Evaluation of intertwin MCA and CPR differences demonstrated the potential for clinical predictive utility in the surveillance of MCDA twin pregnancies.

KEY POINTS

· Intertwin discrepancy of MCA-PSV and CPR is associated with adverse pregnancy outcomes.. · Intertwin differences in Doppler ultrasound may occur prior to meeting diagnostic criteria for TTTS or TAPS.. · There is potential clinical predictive utility in MCA and CPR surveillance of MCDA twin pregnancies..

Obstetric Outcomes in the Surviving Fetus after Intrauterine Fetal Death in Bichorionic Twin Gestations

Twin pregnancies are high-risk gestations that increase the odds of obstetrical complications. They can also present specific and rare complications such as single intrauterine fetal death (IUFD). This complication has been extensively studied in monochorionic but not in bichorionic gestations. Today, the repercussions of IUFD may have on the surviving fetus, mother and bichorionic pregnancy are not known. Our objective was to study materno-obstetrical, fetal, and immediate delivery neonatal complications in bichorionic twin gestations with single IUFD compared to those with both fetuses alive. A retrospective and observational case-control study was performed in bichorionic biamniotic twin pregnancies, 22 complicated with single IUFD after 14 weeks (cases; IUFD group) and 51 with both fetuses alive (controls; non-IUFD group, from Obstetrics Service of La Paz Hospital (Madrid, Spain). The data were collected from obstetrical records. No significant differences were found in the rates of gestational diabetes, gestational hypertension, preeclampsia, neonatal complications, and prematurity between IUFD and non-IUFD groups. Statistical differences were found for the incidence of intrauterine growth restriction in the surviving fetus compared to first fetus of pregnancy with both fetuses alive (22.7% versus 2.0%, respectively; p-value = 0.012). There were no differences compared to second fetus (11.8%; p-value = 0.23). There was a high C-section rate in both groups (IUFD = 63.6%, non-IUFD = 64.7%; p-value = 0.19). In conclusion, single IUFD in bichorionic biamniotic twin gestations is a rare complication that should be closely monitored. It is essential that these gestations be attended by a clinical multidisciplinary team.

Imaging diagnosis and legal implications of brain injury in survivors following single intrauterine fetal demise from monochorionic twins - a review of the literature

Brain injury of the surviving twin from monochorionic pregnancies following intrauterine fetal demise during the second and third trimesters is a rare but severe complication. Monochorionicity and gestational age at the time of stillbirth seem to be decisive factors in terms of long-term neurologic outcome prediction for the survivor. Magnetic resonance imaging (MRI), diffusion weighted imaging (DWI) in particular, seem to bring the earliest and most accurate diagnosis. Ultrasound detection of brain damage is possible in later stages of fetal brain injury. It is essential to provide early diagnosis and multidisciplinary counsel to the parents to ensure informed decision making. For couples who choose to terminate pregnancy legislation related to late abortion might lead to further distress. Our paper aims to stress the importance of MRI DWI in the evaluation of surviving twins following single intrauterine fetal demise in monochorionic pregnancies and the delicate context of the medical professionals and parents facing this clinical situation, sometimes complicated by legal constraints.

Screening, Management and Delivery in Twin Pregnancy

The following AWMF guideline (DGGG/AGG & DEGUM responsible) deals with the diagnosis, screening and management of twins as well as the timing and mode of birth.Twin pregnancies can be classified as dichorionic diamniotic (DC DA), monochorionic diamniotic (MC DA) and monochorionic monoamniotic (MC MA) which are always monochorionic.Twin pregnancies can be concordant (both twins are affected) or discordant (only one twin is affected) for chromosomal defects, malformations, growth restriction and hemodynamic disorders.Chorionicity is the prognostically most significant parameter. Monochorial twins have significantly higher risks of intrauterine morbidity and mortality compared to dichorial twins.In particular, general aspects of twin pregnancies such as dating, determination of chorionicity and amnionicity, the labeling of twin fetuses and the perinatal switch phenomenon are discussed.Routine monitoring of MC and DC twin pregnancies with ultrasound at 11-13^+ 6 weeks of gestation for chromosomal defects, invasive prenatal diagnosis, first-trimester NT or CRL discrepancies, early diagnosis of fetal anatomical defects, and management of twins with abnormalities, including selective fetocide, is described.Second trimester screening and management for preterm birth, intrauterine selective growth restriction (sFGR), classification of monochorial twins with sFGR, and management of the surviving twin after the death of the co-twin are described.Complications exclusively affecting MC twins include Twin to Twin Transfusion Syndrome (TTTS) with the important topics screening, prognosis, complications of laser therapy, timing of delivery, risks for brain abnormalities and delayed neurological development, Twin Anemia-Polycythemia Sequence (TAPS) and Twin Reversed Arterial Perfusion (TRAP) Sequence. This also includes MC MA twins as well as conjoined twins.Finally, the birth mode and time for DC and MC twin pregnancies are described.The information is summarized in 62 recommendations for action, 4 tables and 8 illustrations with comprehensive background texts.The guideline is an international guideline adaptation (ISUOG, NICE) as well as a systematic literature search and is up-to-date.

Multifetal Gestations: Twin, Triplet, and Higher-Order Multifetal Pregnancies: ACOG Practice Bulletin, Number 231

The incidence of multifetal gestations in the United States has increased dramatically over the past several decades. For example, the rate of twin births increased 76% between 1980 and 2009, from 18.9 to 33.3 per 1,000 births (1). However, after more than three decades of increases, the twin birth rate declined 4% during 2014-2018 to 32.6 twins per 1,000 total births in 2018 (2). The rate of triplet and higher-order multifetal gestations increased more than 400% during the 1980s and 1990s, peaking at 193.5 per 100,000 births in 1998, followed by a modest decrease to 153.4 per 100,000 births by 2009 (3). The triplet and higher-order multiple birth rate was 93.0 per 100,000 births for 2018, an 8% decline from 2017 (101.6) and a 52% decline from the 1998 peak (193.5) (4). The long-term changes in the incidence of multifetal gestations has been attributed to two main factors: 1) a shift toward an older maternal age at conception, when multifetal gestations are more likely to occur naturally, and 2) an increased use of assisted reproductive technology (ART), which is more likely to result in a multifetal gestation (5). A number of perinatal complications are increased with multiple gestations, including fetal anomalies, preeclampsia, and gestational diabetes. One of the most consequential complications encountered with multifetal gestations is preterm birth and the resultant infant morbidity and mortality. Although multiple interventions have been evaluated in the hope of prolonging these gestations and improving outcomes, none has had a substantial effect. The purpose of this document is to review the issues and complications associated with twin, triplet, and higher-order multifetal gestations and present an evidence-based approach to management.

Perinatal outcome in monochorionic twin pregnancies after selective fetal reduction using radiofrequency ablation

OBJECTIVE

To study the perinatal outcomes in women with complicated monochorionic twin pregnancies undergoing selective fetal reduction using radiofrequency ablation (RFA).

METHODS

This retrospective study included 44 patients with monochorionic twin pregnancies, between 14 and 28 weeks of pregnancy, who underwent RFA for selective fetal reduction. Perinatal and maternal outcomes and procedure-related complications were analyzed.

RESULTS

The procedure was technically successful in all 44 cases. Indications for selective fetal reduction included twin-to-twin transfusion syndrome (52.3%), twin reversed arterial perfusion (20.5%), twins discordant for anomaly (15.9%), and selective fetal growth restriction (11.4%). Median gestational age at procedure was 22^2/7  weeks (range 14-26^6/7 ). Live birth rate was 77.3% with three neonatal deaths; so overall survival was 70.5%. Median procedure-to-delivery interval was 12^3/7  weeks (range 2^4/7 -23). There were eight losses before 24 weeks of pregnancy, which included two co-twin deaths. Median gestational age at delivery was 35 weeks (interquartile range 32^1/7 -37 weeks). The preterm delivery rate was 66.7% (24/36) and preterm prelabor rupture of membranes (PPROM) occurred in 22.7% (10/44) of patients.

CONCLUSION

Selective fetal reduction using RFA is safe and effective in complicated monochorionic pregnancies. However, the rates of PPROM and preterm delivery remain high.

Outcomes of Monochorionic, Diamniotic Twin Pregnancies with Prenatally Diagnosed Intertwin Weight Discordance

OBJECTIVE

Monochorionic, diamniotic (MCDA) twin pairs are predisposed to various pregnancy complications due to the unique placental angioarchitecture of monochorionicity. Few studies have evaluated the outcomes of weight-discordant MCDA pairs without selective fetal growth restriction (SFGR) or the risk factors for development of SFGR. This study aims to describe the natural history of expectant, noninvasive management of weight-discordant MCDA twins and to evaluate risk factors associated with progression to SFGR.

STUDY DESIGN

This was a retrospective cohort study at a single, tertiary care center in the United States. All MCDA twins with isolated intertwin weight discordance (ITWD) ≥ 20% diagnosed before 26 weeks' gestational age (GA) were included. The primary outcome of descriptive analyses was overall pregnancy outcome, incorporating both survival to delivery and GA at delivery, as defined by the North American Fetal Therapy Network. The secondary outcome was SFGR in one twin (defined as estimated fetal weight < 10% for GA) and factors associated with this progression. Only those with fetal ultrasound (US) within 4 weeks of delivery were included in this secondary analysis.

RESULTS

Among 73 MCDA pairs with ITWD, 73% had a good pregnancy outcome, with dual live delivery at a median GA of 33 weeks. Among the 34 pairs with adequate US follow-up, 56% developed SFGR. There were no differences in GA at delivery or discordance at birth between those who did and those who did not develop SFGR. There was a nonsignificant association between increasing ITWD at diagnosis and subsequent development of SFGR.

CONCLUSION

Expectant, noninvasive management can be considered in MCDA twin pregnancies with ITWD ≥ 20% diagnosed before 26 weeks. This approach is associated with a good pregnancy outcome in the majority of cases, even after the development of SFGR in the smaller twin.

KEY POINTS

· Nearly 75% of weight-discordant mo/di twins have a good pregnancy outcome.. · Weight-discordant mo/di twins deliver at a mean gestational age of 33 weeks without invasive therapy.. · Noninvasive management should be considered for weight-discordant mo/di twins..

Fetal Growth in Multiple Gestations: Evaluation and Management

Multifetal gestation pregnancies present a clinical challenge due to unique complications including growth issues, prematurity, maternal risk, and pathologic processes, such as selective intrauterine growth restriction (sIUGR), twin-to-twin transfusion syndrome (TTTS), and twin anemia-polycythemia sequence. If sIUGR is found, then management may involve some combination of increased surveillance, fetal procedures, and/or delivery. The combination of sIUGR with TTTS or other comorbidities increases the risk of pregnancy complications. Multifetal pregnancy reduction is an option when a problem is confined to a single fetus or when weighing the risks and benefits of a multifetal gestation in comparison to a singleton pregnancy.

Twin to twin transfusion syndrome

Twin to twin transfusion syndrome (TTTS) is a common complication that typically presents in the second trimester of pregnancy in 10-15% of monochorionic twins due to net transfer of volume and hormonal substances from one twin to the other across vascular anastomoses on the placenta. Without recognition and treatment, TTTS is the greatest contributor to fetal loss prior to viability in 90-100% of advanced cases. Ultrasound diagnosis of monochorionicity is most reliable in the first trimester and sets the monitoring strategy for this type of twins. The diagnosis of TTTS is made by ultrasound with the findings of polyhydramnios due to volume overload and polyuria in one twin and oligohydramnios due to oliguria of the co-twin. Assessment of bladder filling as well as arterial and venous Doppler patterns are required for staging disease severity. Assessment of fetal cardiac function also provides additional insight into the fetal cardiovascular impacts of the disease as well as help identify fetuses that may require postnatal follow up. Fetoscopic laser ablation of the communicating vascular anastomoses between the twins is the standard treatment for TTTS. It aims to cure the condition by interrupting the link between their circulations and making them independent of one another. Contemporary outcome data after laser surgery suggests survival for both fetuses can be anticipated in up to 65% of cases and survival of a single fetus in up to 88% of cases. However, preterm birth remains a significant contributor to postnatal morbidity and mortality. Long term outcomes of TTTS survivors indicate that up to 11% of children may show signs of neurologic impairment. Strategies to minimize preterm birth after treatment and standardized reporting by laser centers are important considerations to improve overall outcomes and understand the long-term impacts of TTTS.

Radiofrequency ablation for selective fetal reduction in complicated Monochorionic twins; comparing the outcomes according to the indications

Background

To evaluate the perinatal outcomes in women with complicated monochorionic diamniotic twins who underwent selective reduction using radiofrequency ablation (RFA).

Methods

This retrospective study included patients with complicated monochorionic diamniotic twins between 16 to 28 weeks who underwent selective reduction using RFA.

Results

During the study period, 143 women with complicated monochorionic twins underwent RFA including 52 with selective fetal growth restriction (sFGR), 48 with twin to twin transfusion syndrome (TTTS), 33 with major fetal anomalies in one of the twins, and 10 with reversed arterial perfusion sequence (TRAP). The overall survival was 71.3% (102/143). The procedures were technically successful in achieving selective termination in all cases. The mean ± SD of gestational age at the time of the procedure was 21.0 ± 2.3 weeks. The mean ± SD of gestational age at delivery was 34.6 ± 3.3 weeks. The mean ± SD of overall procedure-to-delivery time was 12 ± 1.7 weeks. The pregnancy success rates among sFGR, TRAP, TTTS and anomaly groups were 82.7, 80, 73 and 60.7% respectively. There were no maternal complications.

Conclusion

Radiofrequency ablation for fetal reduction in complicated monochorionic twin pregnancies appears to be a reasonable option. The pregnancy success rate following RFA selective reduction was highest among sFGR and TRAP groups and lowest in the anomaly group.

Temporal persistence of residual fetal cell-free DNA from a deceased cotwin after selective fetal reduction in dichorionic diamniotic twin pregnancies

OBJECTIVES

To determine the temporal persistence of the residual cell-free DNA (cfDNA) of the deceased cotwin in maternal circulation after selective fetal reduction and evaluate its long persistence in noninvasive prenatal testing (NIPT).

METHODS

Dichorionic diamniotic twins (N = 5) undergoing selective fetal reduction because of a trisomy were recruited. After informed consent, maternal blood was collected immediately before reduction and periodically after reduction until birth. The plasma cfDNA of each sample was sequenced and analyzed for fetal aneuploidy and fetal fractions.

RESULTS

In all pregnancies, the fetal fraction of the cfDNA of the deceased fetus increased to peak at 7-9 weeks after fetal reduction, and subsequently decreased gradually to almost undetectable during the late third trimester. The NIPT T-scores persistently reflected the detection of fetal trisomy up to 16 (median 9.5) weeks after fetal reduction.

CONCLUSIONS

Residual cfDNA from the deceased cotwin after selective reduction at 14-17 gestational weeks led to the persistent generation of false-positive NIPT results for up to 16 weeks postdemise. Thus, providing NIPT for pregnancies with a cotwin demise in early second trimester is prone to misleading results and not recommended.

Neurologic Outcomes After Prenatal Treatment of Twin-Twin Transfusion Syndrome

Monochorionic twin gestations possess disproportionately higher risk for perinatal morbidity and mortality when compared with dichorionic twin pregnancies due to their potential to develop specific complications attributable to a shared placenta and intertwin placental circulation. Since the advent of fetoscopic laser surgery, outcomes of pregnancies affected by twin-twin transfusion syndrome (TTTS) have improved, with reduced rates of mortality and morbidity when compared with amnioreduction or expectant management. The focus of this article is to review the literature regarding neurologic outcomes among pediatric survivors of fetal intervention for TTTS.

Selective fetal reduction in complicated monochorionic twin pregnancies: A comparison of techniques

OBJECTIVE

To compare perinatal outcomes associated with three methods of selective reduction in complicated monochorionic (MC) twin pregnancies: bipolar cord coagulation (BC), fetoscopic or ultrasound guided laser cord occlusion and radiofrequency ablation (RFA).

METHODS

Retrospective cohort study of complicated MC twin pregnancies undergoing selective fetal reduction at a tertiary fetal center over a 20-year period. Obstetric and perinatal outcomes were compared.

RESULTS

105 procedures met inclusion criteria: 74 RFAs, 17 lasers and 14 BCs. Procedure duration was significantly shorter for RFA (27.4 ± 15.8 minutes) compared to BC (91.7 ± 38.7 minutes) and laser (83.4 ± 40.4 minutes), P < .0001). The incidence of preterm prelabor rupture of membranes (PPROM) and co-twin demise did not differ between groups, however preterm delivery <34 weeks occurred less frequently following RFA (29.7%), compared to laser (64.7%) or BC (42.9%) (P = .02); delivery <37 weeks was also less frequent following RFA (45.9%), compared to laser (76.5%) or BC (78.6%)(P = .01). The difference in preterm birth<34 weeks between RFA and laser was maintained after adjusting for cord occlusion indication and amnionicity (OR 3.96, 95% CI 1.27-12.31).

CONCLUSIONS

In our experience, RFA procedures were simpler, faster and associated with a lower risk of preterm delivery <34 and <37 weeks, compared to laser or BC.

The incidence, maternal, fetal and neonatal consequences of single intrauterine fetal death in monochorionic twins: A prospective observational UKOSS study

Objective

Report maternal, fetal and neonatal complications associated with single intrauterine fetal death (sIUFD) in monochorionic twin pregnancies.

Design

Prospective observational study.

Setting

UK.

Population

81 monochorionic twin pregnancies with sIUFD after 14 weeks gestation, irrespective of cause.

Methods

UKOSS reporters submitted data collection forms using data from hospital records.

Main outcome measures

Aetiology of sIUFD; surviving co-twin outcomes: perinatal mortality, central nervous system (CNS) imaging, gestation and mode of delivery, neonatal outcomes; post-mortem findings; maternal outcomes.

Results

The commonest aetiology was twin-twin transfusion syndrome (38/81, 47%), “spontaneous” sIUFD (22/81, 27%) was second commonest. Death of the co-twin was common (10/70, 14%). Preterm birth (<37 weeks gestation) was the commonest adverse outcome (77%): half were spontaneous and half iatrogenic. Only 46/75 (61%) cases had antenatal CNS imaging, of which 33 cases had known results of which 7/33 (21%) had radiological findings suggestive of neurological damage. Postnatal CNS imaging revealed an additional 7 babies with CNS abnormalities, all born at <36 weeks, including all 4 babies exhibiting abnormal CNS signs. Major maternal morbidity was relatively common, with 6% requiring ITU admission, all related to infection.

Conclusions

Monochorionic twin pregnancies with single IUD are complex and require specialist care. Further research is required regarding optimal gestation at delivery of the surviving co-twin, preterm birth prevention, and classifying the cause of death in twin pregnancies. Awareness of the importance of CNS imaging, and follow-up, needs improvement.

Management of monochorionic twins discordant for structural fetal anomalies

OBJECTIVE

To review the perinatal management and outcomes of monochorionic twin pregnancies (MC) discordant for congenital anomalies (DCA).

METHODS

Retrospective, study of all MC DCA cases referred to our tertiary referral center from 1997 to 2018. We excluded cases complicated with twin-to-twin transfusion syndrome, twin anemia-polycythemia sequence, twin reversed arterial perfusion sequence or selective intra-uterine growth restriction. Patients were counseled about the possibility of expectant (EM) or interventional management (selective feticide [SF] or termination of the entire pregnancy [TOP]).

RESULTS

One hundred eight of 4157 (2.6%) MC pregnancies were discordant for anomaly. Fifty two of 108 n(48.1%) underwent SF at a mean gestational age of 31.4 ± 5.9 weeks while 52/108(48.1%) opted for EM. Livebirth rate of the healthy co-twin was similar between the two groups (SF: 88.5% vs EM: 82.7%, P = .87). In the SF group, six healthy co-twins (6/52, 11.5%) died 5.3 ± 3.1 days after SF of the abnormal co-twin. In the EM group, in-utero demise of the abnormal twin occurred in 9 of 52 (17.3%) of the cases and was followed by the spontaneous demise of the healthy co-twin in 4 of 9 (44.4%) of these cases.

CONCLUSION

Selective feticide does not seem to significantly alter survival of the healthy co-twin compared to EM.

Risk Factors for Co-Twin Fetal Demise following Radiofrequency Ablation in Multifetal Monochorionic Gestations

BACKGROUND

Umbilical cord occlusion via radiofrequency ablation (RFA) is utilized to maximize outcomes of the co-twin in complicated multifetal monochorionic (MC) gestations. However, post-procedure co-twin fetal demise is of concern.

OBJECTIVE

The aim of this study was to determine risk factors for co-twin fetal demise following RFA.

METHODS

This is a retrospective study of MC multiples that underwent RFA. Indications for RFA included twin reversed arterial perfusion (TRAP) sequence, selective fetal growth restriction (sFGR) type II, discordant lethal anomalies, and twin-twin transfusion syndrome (TTTS) with proximate placental cord insertion sites. The primary outcome was co-twin fetal demise. Bivariate analyses and multiple logistic regression modeling of identified risk factors were conducted.

RESULTS

Of 36 patients studied, surgical indications were: TRAP (n = 15, 41.7%), sFGR (n = 10, 27.8%), discordant anomalies (n = 9, 25.0%), and TTTS (n = 2, 5.6%). Nine patients (25.0%) experienced a co-twin fetal demise. In multiple logistic regression analysis, fetal growth restriction (FGR) of one co-twin was associated with increased risk of co-twin fetal demise (OR = 10.85, 95% CI 1.03-114.48, p = 0.0474) and a preoperative diagnosis of TRAP was protective against fetal demise (OR = 0.06, 95% CI 0.00-0.84, p = 0.0368).

CONCLUSION

Co-twin FGR was associated with an increased risk of post-RFA demise. When compared to other indications, patients with TRAP sequence were less likely to have a co-twin demise.

Twin-Twin Transfusion Syndrome Complicated by Proximate Placental Cord Insertion Sites: Endoscopic Clip-Assisted Laser Occlusion

INTRODUCTION

Severe twin-twin transfusion syndrome (TTTS) with a large vascular communication between proximate placental cord insertion sites is a therapeutic dilemma because laser ablation may cause thermal injury to the cord roots and subsequent fetal demise.

CASE PRESENTATION

Stage IV TTTS with placental cord insertion sites 1.3 cm apart and with an intervening large arterio-arterial (AA) anastomosis presented for treatment. The application of endoclips onto the large AA anastomosis between the cord roots allowed for successful laser occlusion using minimal energy. Both the donor and recipient twins were alive and well at 6 months of age.

CONCLUSION

Endoscopic clip-assisted laser occlusion of a placental vessel is technically feasible and may be a useful therapeutic option in select cases.

Magnetic resonance imaging of the fetal brain in monochorionic diamniotic twin gestation: correlation of cerebral injury with ultrasound staging and survival outcomes

BACKGROUND

The current staging system of twin-twin transfusion syndrome (TTTS) is based on the ultrasound criteria and does not consider the cerebral injury.

OBJECTIVE

To assess the incidence of cerebral damage on fetal MRI and correlate abnormal cerebral diffusion-weighted imaging (DWI) findings with survival outcome and the ultrasound staging of TTTS.

MATERIALS AND METHODS

We conducted a retrospective review of MRI/DWI of fetal brains and the electronic medical records in monochorionic diamniotic twin gestations. Axial DWI of each fetal brain was performed on 1.5-tesla (T) clinical magnet with b values of 0 s/mm² and 700 s/mm². We correlated MRI/DWI abnormalities with the Quintero staging system and survival outcomes of the fetuses.

RESULTS

Thirty-four pregnancies (68 fetuses) with 42 fetal cerebral abnormalities were identified by MRI/DWI alone. Of these 42 fetal cerebral abnormalities, 33 fetal brain lesions were visible only on DWI (n=25 donor, n=8 recipients; n=30 unilateral, n=3 bilateral; n=26 diffuse, n=7 focal). Quintero staging in these 34 pregnancies was as follows: 9 Stage I, 7 Stage II, 13 Stage III, 4 Stage IV, 1 Stage V. There was no significant correlation between the presence of cerebral infarction or hemorrhage using MRI/DWI and ultrasound staging (P=0.138). The overall survival rate was 63.2% (43/68). There was a significant correlation between the presence of cerebral infarction or hemorrhage on MRI/DWI and delivery status (P=0.009).

CONCLUSION

Abnormal cerebral imaging findings on MRI/DWI from hypoxic-ischemic injury or hemorrhage can be seen at the beginning of the second trimester and do not correlate with the current ultrasound staging system; however, they do correlate with decreased survival. Fetal cerebral abnormalities could be incorporated into the TTTS staging system as an independent risk factor.

Comparisons between two methods of multifetal pregnancy reduction in women with a dichorionic triamniotic triplet pregnancy

OBJECTIVE

To compare the different pregnancy outcomes of women with a reduced dichorionic triamniotic (DCTA) triplet managed with radiofrequency ablation (RFA) or potassium chloride (KCL).

MATERIALS AND METHODS

This was a retrospective cohort study. We studied 30 women of DCTA triplets managed with RFA as well as 85 managed with KCL. We compared the mean neonatal birthweight, median gestational age and perinatal mortality of two groups.

RESULTS

The mean neonatal birthweight of children in RFA group was 2572.4 g (SD, 407.0), vs 2899.3 g (SD, 554.9) in KCL group (P < 0.001). The rate of low birth weight infants was 23 (42.6%) vs. 16 (18.0%), respectively, (p < 0.005). However, there was no statistically significant difference in the median gestational age of delivery, premature birth before 32&37 weeks' gestation, neonatal brain injury or successful pregnancy between two groups. (We define the successful pregnancy as the condition that at least one child survives for a specific woman, while the failed one as no child survives.) CONCLUSION: What we took it for granted was that pregnancy outcomes in women with a reduced DCTA triplet managed with RFA was riskier than with KCL, however, we proved that it is not accurate. For women with a reduced DCTA triplet, managed with RFA is not much riskier than with KCL. What's more, most women have two children survived in RFA group, while in KCL group, only one child survives for most women. This result may change the management alternative for those women with DCTA triplet pregnancies who choose reduction, especially for women who desire to have two surviving and healthy fetuses.

Selective intrauterine growth restriction (SIUGR) type II: proposed subclassification to guide surgical management

Background: Optimal surgical management of monochorionic diamniotic twins complicated by selective intrauterine growth restriction (SIUGR) type II is unknown. Surgical management may involve selective laser photocoagulation of communicating vessels (SLPCV), which offers the possibility of dual twin survivors versus umbilical cord occlusion (UCO) of the SIUGR twin.Objective: To identify patient characteristics associated with SIUGR twin survival for those undergoing SLPCV.Study design: All patients studied were those who underwent fetal treatment for SIUGR type II at our center from 2006-2018. SIUGR type II was defined as an estimated fetal weight <10th percentile with persistent absent and/or reversed end diastolic flow in the umbilical artery of the SIUGR twin, in the absence of twin-twin transfusion syndrome. Patients were offered SLPCV versus UCO, and those undergoing SLPCV, patient characteristics associated with 30-day survival of the SIUGR twin were examined using bivariate analysis and multiple logistic regression models.Results: Fifty-four consecutive SIUGR type II patients were treated, 45 via SLPCV and nine via UCO. Of the 45 SLPCV cases, there were 16 (35.6%) with SIUGR twin (and dual) survival. SIUGR twin survival appeared associated with middle cerebral artery (MCA) peak systolic velocity (psv) <1.5 multiples of the median, and forward atrial systolic flow in the ductus venosus (DV). In a post hoc analysis, we subsequently categorized patients as: SIUGR type IIa (N = 32 (71.1%)): normal MCA psv, and normal DV waveform, versus SIUGR type IIb (N = 13 (28.9%)): MCA psv ≥1.5 multiples of the median, and/or DV with absent or reversed atrial systolic flow. Thirty-day survival of the SIUGR twin was 50% for type IIa and 0% for type IIb.Conclusion: Over one-third of SIUGR type II patients experienced dual survival after treatment with laser surgery. Normal MCA psv and normal DV waveforms were associated with SIUGR type II survival of the SIUGR twin. Post hoc exploration and subclassification of SIUGR type II patients by preoperative Doppler indices created two groups, one (type IIa) with 50% survival and one (type IIb) with 0% survival of the SIUGR twin after laser surgery. Upon further confirmation, these findings may provide guidance for counseling patients and conducting fetal therapy.

Outcome of ICSI pregnancies with spontaneous loss of a co-twin compared with singleton ICSI pregnancies: Single center experience

AIM

To compare the outcome of intracytoplasmic sperm injection (ICSI) pregnancies complicated by spontaneous loss of a dichorionic co-twin with that of singleton ICSI pregnancies.

METHODS

The study group included dichorionic ICSI pregnancies with co-twin loss (n = 33) and the control group included ICSI pregnancies with a singleton from the beginning (n = 327). Primary outcome measures were obstetric complications, including preterm delivery, newborn small for gestational age, gestational diabetes, gestational hypertensive disorders and abruptio placenta; admission to neonatal intensive care unit (NICU) and perinatal mortality observed in the study and control groups. Statistical analysis was performed using spss for Windows, version 22.0.

RESULTS

In the study group, there were 26 cases of first trimester (early) and 7 cases of second or third trimester (late) co-twin losses. Mean gestational age at delivery and mean birth weight were significantly lower in the whole study group compared to control (P < 0.05). Preterm delivery and NICU admission rates were significantly higher in the whole study group, compared to control (39.3% vs 14.6% and 36.36% vs 11.69% respectively, P < 0.05), but did not show significant difference between early loss subgroup and control (P > 0.05). Preterm delivery rate was significantly higher in the late loss subgroup compared to the early loss subgroup (85.71% vs 26.92% P < 0.05).

CONCLUSION

Loss of a co-twin in dichorionic ICSI pregnancies is associated with increased risk of preterm birth. This risk is significantly higher in cases with late loss compared to the early loss cases.

Perinatal mortality and morbidity in triplet pregnancy according to chorionicity: systematic review and meta-analysis

OBJECTIVE

The incidence of perinatal mortality and morbidity in triplet pregnancies according to chorionicity is yet to be established. The aim of this systematic review was to quantify perinatal mortality and morbidity in trichorionic triamniotic (TCTA), dichorionic triamniotic (DCTA) and monochorionic triamniotic (MCTA) triplets.

METHODS

MEDLINE, EMBASE and CINAHL databases were searched in December 2017 for literature published in English describing outcomes of DCTA, TCTA and/or MCTA triplet pregnancies. Primary outcomes were intrauterine death (IUD), neonatal death, perinatal death (PND) and gestational age at birth. Secondary outcomes comprised respiratory, neurological and infectious morbidity, as well as a composite score of neonatal morbidity. Data regarding outcomes were extracted from the included studies. Random-effects meta-analysis was used to estimate the risk of mortality and morbidity and to compute the difference in gestational age at birth between TCTA and DCTA triplet pregnancies.

RESULTS

Nine studies (1373 triplet pregnancies, of which 1062 were TCTA, 261 DCTA and 50 MCTA) were included in the analysis. The risk of PND was higher in DCTA than in TCTA triplet pregnancies (odds ratio (OR), 3.3 (95% CI, 1.3-8.0)), mainly owing to the higher risk of IUD in DCTA triplet pregnancies (OR, 4.6 (95% CI, 1.8-11.7)). There was no difference in gestational age at birth between TCTA and DCTA triplets (mean difference, 1.1 weeks (95% CI, -0.3 to 2.5 weeks); I²  = 85%; P = 0.12). Neurological morbidity occurred in 2.0% (95% CI, 1.1-3.3%) of TCTA and in 11.6% (95% CI, 1.1-40.0%) of DCTA triplets. Respiratory and infectious morbidity affected 28.3% (95% CI, 20.7-36.8%) and 4.2% (95% CI, 2.8-5.9%) of TCTA and 34.0% (95% CI, 21.5-47.7%) and 7.1% (95% CI, 2.7-13.3%) of DCTA triplets, respectively. The incidence of composite morbidity in TCTA and DCTA triplets was 29.6% (95% CI, 21.1-38.9%) and 34.0% (95% CI, 21.5-47.7%), respectively. When translating these figures into a risk analysis, the risk of neurological morbidity (OR, 5.4 (95% CI, 1.6-18.3)) was significantly higher in DCTA than in TCTA triplets, while there was no significant difference in the other morbidities explored. Only one study reported on outcomes of MCTA pregnancies, hence, no formal comparison with the other groups was performed.

CONCLUSION

DCTA triplets are at higher risk of perinatal mortality and morbidity than are TCTA triplets. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Multicystic encephalomalacia and gastrointestinal injury following single fetal death in first trimester and subsequent fetofetal transfusion syndrome in a monochorionic triplet pregnancy: a case report

BACKGROUND

Monochorionic multifetal pregnancies are at increased risk of adverse perinatal outcome because of placental vascular anastomoses. We present a case of multicystic encephalomalacia and gastrointestinal injury in two surviving fetuses following single fetal death in first trimester and subsequent fetofetal transfusion syndrome in a monochorionic triplet pregnancy.

CASE PRESENTATION

A 31-year-old nulliparous woman had a spontaneous monochorionic triamniotic triplet pregnancy. Three live fetuses with single placenta were seen at 8-week ultrasound scan. One fetus demised at 11 weeks and 3 days of gestation. Dilated echogenic bowel and ascites were found in one surviving fetus at 23 weeks of gestation. At 28 weeks of gestation, the pregnancy was complicated by fetofetal transfusion syndrome in which discordant amniotic fluid volumes were found. Two days later, emergency Caesarean section was performed because of worsening of fetal Doppler and biophysical profile. One baby was found to have jejunal atresia requiring surgery at 4 days old. He had periventricular leukomalacia and intracranial haemorrhage, but subsequent normal neurological development. Another baby had gastric perforation requiring surgery at 2 days old. He was confirmed to have multicystic encephalomalacia by cranial ultrasound and magnetic resonance imaging. He suffered from developmental delay, epilepsy and cerebral palsy.

CONCLUSION

This case alerts the obstetricians the possible hypoxic-ischemic injury to the survivors of monochorionic triplet pregnancy after the co-triplet death in the first trimester and fetofetal transfusion syndrome. Antenatal assessment and postnatal follow-up are important for these high-risk multiple pregnancies.

Complex multigestational anomalies

The increase in multiple gestation pregnancies has resulted in significant health care implications for both mother and child. Our ability to diagnose and intervene on an at-risk multi-gestation pregnancy has dramatically improved. It is important for the pediatric surgeon to be equipped with a basic fund of knowledge concerning these pregnancies. An understanding of amnionicity and chorionicity will equip the practitioner with the ability to identify which pregnancies are at risk for specific complications. This article highlights multi-gestation pregnancies that are monochorionic (single shared placenta) and can be complicated by twin-twin transfusion syndrome (TTTS), twin reversed arterial perfusion (TRAP) sequence, twin anemia polycythemia sequence (TAPS), or selective fetal intrauterine growth restriction (sIUGR). The risk of fetal demise is significant in these pregnancies. Understanding recommended surveillance and warning signs can alert surgeons to developing complications. Specialized fetal care centers possess the ability to intervene on these pregnancies in utero.