Stillbirth and neonatal mortality in monochorionic and dichorionic twins: a population-based study

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.

Association between twin status with cognitive, behavioral development and brain structure in early adolescence: a retrospective cohort analysis based on the Adolescent Brain Cognitive Development Study

Twin births are related with maternal and fetal adverse outcomes. Little was known about the comparability of the cognitive, behavioral development and brain structure between twins and singletons in early adolescence. This retrospective cohort study was based on data from the United States population-based, prospective, longitudinal observational Adolescent Brain Cognitive Development study. Children with complete twin status information were enrolled, and the exposure variable was twin status. Primary outcomes were cognitive, behavioral development and brain structure in early adolescence. Cognitive and behavioral outcomes were assessed by using the NIH Toolbox and Child Behavioral Checklist, respectively. Brain structure was evaluated by the cortical thickness, area, and volume extracted from the magnetic resonance imaging (MRI) data. Subgroup analyses were conducted by prematurity, birth weight, with sibling, genetic profiles, and twin types (zygosity). From 1st September 2016 to 15th November 2018, 11545 children (9477 singletons and 2068 twins) aged 9-10 years were enrolled. Twins showed mildly lower cognitive performance (|t|> 5.104, P-values < 0.001, False Discovery Rate [FDR] < 0.001), better behavioral outcome (|t|> 2.441, P-values < 0.015, FDR < 0.042), such as lower scores for multiple psychiatric disorders and behavioral issues, and smaller cortical volume (t = - 3.854, P-values < 0.001, FDR < 0.001) and cortical area (t = - 3.872, P-values < 0.001, FDR < 0.001). The observed differences still held when stratified for prematurity, birth weight, presence of siblings, genetic profiles, and twin types (zygosity). Furthermore, analyses on the two-year follow-up data showed consistent results with baseline data. Twin status is associated with lower cognitive and better behavioral development in early adolescence accompanied by altered brain structure. Clinicians should be aware of the possible difference when generalizing results from adolescent twin samples to singletons.

Monochorionic Twinning in Bioengineered Human Embryo Models

Monochorionic twinning of human embryos increases the risk of complications during pregnancy. The rarity of such twinning events, combined with ethical constraints in human embryo research, makes investigating the mechanisms behind twinning practically infeasible. As a result, there is a significant knowledge gap regarding the origins and early phenotypic presentation of monochorionic twin embryos. In this study, a microthermoformed-based microwell screening platform is used to identify conditions that efficiently induce monochorionic twins in human stem cell-based blastocyst models, termed "twin blastoids". These twin blastoids contain a cystic GATA3+ trophectoderm-like epithelium encasing two distinct inner cell masses (ICMs). Morphological and morphokinetic analyses reveal that twinning occurs during the cavitation phase via splitting of the OCT4+ pluripotent core. Notably, each ICM in twin blastoids contains its own NR2F2+ polar trophectoderm-like region, ready for implantation. This is functionally tested in a microfluidic chip-based implantation assay with epithelial endometrium cells. Under defined flow regimes, twin blastoids show increased adhesion capacity compared to singleton blastoids, suggestive of increased implantation potential. In conclusion, the development of technology enabling large-scale formation of twin blastoids, coupled with high-sensitivity readout capabilities, presents an unprecedented opportunity for systematically exploring monochorionic twin formation and its impact on embryonic development.

The Association of Twin Chorionicity with Maternal Outcomes

OBJECTIVE

Our objective was to investigate the association between maternal outcomes and twin chorionicity in a large, contemporary obstetric population.

STUDY DESIGN

Retrospective cohort study was conducted at a single, large tertiary care center. Prenatal and inpatient records for all individuals with twin gestations were reviewed from 2000 to 2016. Patients with monoamniotic twins, higher-order multiples reduced to twins, multiple sets of twins in the study period, or undetermined chorionicity were excluded. Patients with monochorionic twins were compared with those with dichorionic twins. The co-primary outcomes were gestational diabetes mellitus and hypertensive disorders of pregnancy. Secondary outcomes included cesarean delivery, preterm delivery, postpartum hemorrhage, and other maternal outcomes. Bivariate and multivariate analyses were performed to assess associations of chorionicity with maternal outcomes.

RESULTS

Of the 2,979 patients eligible for inclusion, 2,627 (88.2%) had dichorionic twin gestations and 352 (11.8%) had monochorionic twin gestations. Patients with monochorionic twins were less likely to self-identify as non-Hispanic White and to have conceived via assisted reproductive technology but were more likely to be publicly insured, multiparous and have prenatal care with a maternal-fetal medicine provider. Neither gestational diabetes mellitus (6.8% monochorionic vs. 6.2% dichorionic, p = 0.74; adjusted odds ratio [OR] 1.06, 95% confidence interval (CI) 0.60-1.86) nor hypertensive disorders of pregnancy (21.9% monochorionic vs. 26.3% dichorionic, p = 0.09; adjusted OR 0.99, 95% CI, 0.71-1.38) differed by chorionicity. Of the secondary maternal outcomes, patients with monochorionic twins experienced a lower frequency of cesarean delivery (46.0 vs. 61.8%, p < 0.001), which persisted after multivariate analyses (adjusted OR 0.60, 95% CI 0.46-0.80). There were no differences in preterm delivery, preterm premature rupture of membranes, hemorrhage, hysterectomy, or intrahepatic cholestasis of pregnancy.

CONCLUSION

The odds of gestational diabetes mellitus and hypertensive disorders of pregnancy do not appear to differ by twin chorionicity.

KEY POINTS

· Hypertensive disorders of pregnancy do not differ by twin chorionicity.. · Gestational diabetes mellitus does not differ by twin chorionicity.. · Maternal outcomes are similar for individuals with monochorionic and dichorionic twin gestations..

Birth weight discordance and adverse neonatal outcomes in appropriately grown premature twins

Objective

This study aimed to analyze the clinical characteristics of birth weight discordant twins (BWDT) who were premature and appropriate-for-gestational-age or large-for-gestational-age. Additionally, it assessed the impact of birth weight discordance on the prognosis of appropriately grown premature twins, and investigated the effect of maternal factors on neonatal outcomes.

Study design

This retrospective cohort study included twins who were born alive after preterm labor at the Nanjing Drum Tower Hospital from January 2018 to December 2021, along with their mothers. Twins were arranged into discordant and concordant groups according to intertwin birth weight discordance, followed by the analysis of the clinical characteristics of mothers and the prognosis of neonates.

Results

A total of 585 mothers and 1170 neonates were included, with 47 mothers and 94 neonates in the discordant group. The incidence of birth weight discordance was 8.0% (94/1,170) in appropriately grown premature twins. The incidence of complications (43.2% vs. 21.8%) and transfer to the neonatal intensive care unit (NICU) (53.2% vs. 29.2%) was higher in the discordant group than in the concordant group (p < 0.05). Furthermore, the incidence of infectious diseases (36.7% vs. 19.4%), necrotizing enterocolitis (7.6% vs. 1.6%), and oxygen therapy rate (22.8% vs. 12.8%) were statistically significantly higher in the discordant group than in the concordant group (p < 0.05).

Conclusion

Birth weight discordance remains a high-risk factor for complications and transfer to the NICU in appropriately grown premature twins. It is important to pay attention to birth weight discordance when the outcomes of twins are assessed.

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.

Maternal and perinatal risks for monozygotic twins conceived following frozen-thawed embryo transfer: a retrospective cohort study

BACKGROUND

The present study aimed to explore the maternal and perinatal risks in cases of monozygotic twins (MZT) following frozen-thawed embryo transfer (FET).

METHODS

All twin births that were conceived following FET from 2007 to 2021 at Shanghai Ninth People's Hospital in Shanghai, China were retrospectively reviewed. The exposure variable was twin type (monozygotic and dizygotic). The primary outcome was the incidence of neonatal death while secondary outcomes included hypertensive disorders of pregnancy, gestational diabetes, intrahepatic cholestasis of pregnancy, placenta previa, placental abruption, preterm premature rupture of the membranes, Cesarean delivery, gestational age, birth weight, weight discordance, stillbirth, birth defects, pneumonia, respiratory distress syndrome, necrotizing enterocolitis, and neonatal jaundice. Analysis of the outcomes was performed using logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). The causal mediation analysis was conducted. A doubly robust estimation model was used to validate the results. Kaplan-Meier method was used to calculate survival probability. The sensitivity analysis was performed with a propensity score-based patient-matching model.

RESULTS

Of 6101 dizygotic twin (DZT) and 164 MZT births conceived by FET, MZT showed an increased risk of neonatal death based on the multivariate logistic regression models (partially adjusted OR: 4.19; 95% CI, 1.23-10.8; fully adjusted OR: 4.95; 95% CI, 1.41-13.2). Similar results were obtained with the doubly robust estimation. Comparing MZT with DZT, the neonatal survival probability was lower for MZT (P < 0.05). The results were robust in the sensitivity analysis. Females with MZT pregnancies exhibited an elevated risk of preterm premature rupture of the membranes (adjusted OR: 2.42; 95% CI, 1.54-3.70). MZT were also associated with higher odds of preterm birth (prior to 37 weeks) (adjusted OR: 2.31; 95% CI, 1.48-3.67), low birth weight (adjusted OR: 1.92; 95% CI, 1.27-2.93), and small for gestational age (adjusted OR: 2.18; 95% CI, 1.21-3.69) in the fully adjusted analyses. The effect of MZT on neonatal death was partially mediated by preterm birth and low birth weight (P < 0.05).

CONCLUSIONS

This study indicates that MZT conceived by FET are related to an increased risk of neonatal death, emphasizing a potential need for comprehensive antenatal surveillance in these at-risk pregnancies.

Fetal Growth and Antenatal Testing in Uncomplicated Multiple Gestations

Multiple gestations experience a slowing of fetal growth in the third trimester and have been described as having a higher risk of growth restriction. Whether this increased diagnosis of fetal growth restriction is physiological or pathologic is controversial. In an attempt to better identify those fetuses most at risk, twin-specific growth charts have been developed and tested. In addition, there are data to suggest that multiple gestations experience an increased risk of unexpected third-trimester stillbirth in apparently uncomplicated pregnancies. This chapter reviews the current data and recommendations for fetal growth assessment, antenatal surveillance, and delivery timing in uncomplicated multiple gestations.

The risk factors of procedure-related complications after amniocentesis in twin pregnancies: a retrospective analysis

BACKGROUND

There is an increasing demand for prenatal diagnostic testing in twin pregnancies, however, anecdotally there is a higher incidence of procedure-related complications after amniocentesis than that in singleton pregnancies. There is a paucity of data regarding risk factors of amniocentesis in twin pregnancies.

METHODS

Women with twin pregnancies who underwent amniocentesis between January 2016 and December 2020 were enrolled in this retrospective study. Procedure-related complications including spontaneous miscarriage, intrauterine fetal death, spontaneous preterm delivery, preterm premature rupture of membranes, and placental abruption in one or both fetuses after amniocentesis were assessed. Meanwhile, potential risk factors related to amniocentesis including chorionicity, gestational age, conception, number of needle insertions, parity, history of miscarriage, indications, and pregnancy-related complications (pregnancy-induced hypertension and gestational diabetes) were also recorded.

RESULTS

A total of 811 women with twin pregnancies underwent amniocentesis were included, with a procedure-related complications rate of 3.83%. Risk factors associated with increased risk of procedure-related complications after amniocentesis in twin pregnancies were chorionicity (adjusted odds ratio [aOR]: 4.06), gestational age at the procedure (aOR: 2.76), and numbers of needle insertions (aOR: 3.26). In the monochorionic twin pregnancy, hemorrhage during this pregnancy (aOR: 12.01), polyhydramnios (aOR: 5.03), and numbers of needle insertions (aOR: 3.15) were risk factors after amniocentesis. In the dichorionic twin pregnancy, gestational age at the procedure (OR:4.47) affected the risk of procedure-related complications after amniocentesis. In the subgroup of gestational age at the procedure ≤ 24+ 0 weeks, risk factors associated with increased risk of procedure-related complications after amniocentesis in twin pregnancies were chorionicity (aOR: 5.14), and numbers of needle insertions (aOR: 3.76).

CONCLUSION

The procedure-related complications rate is 3.83% in our institution during the study period. The present study has emphasized the significance of certain risk factors for adverse outcome and will be useful in counseling patients with twin pregnancies.

Adverse outcome following selective termination of presenting twin vs non-presenting twin

OBJECTIVE

Data are lacking on the impact on pregnancy outcome of the position of the abnormal fetus in a discordant twin pregnancy undergoing selective termination (ST). Tissue maceration post ST of the presenting twin may lead to early rupture of membranes, amnionitis and preterm labor. The aim of this study was to evaluate pregnancy complications and outcome following ST of the presenting vs non-presenting twin.

METHODS

This was a multicenter retrospective cohort study of dichorionic diamniotic twin pregnancies that underwent ST due to a discordant fetal anomaly (structural or genetic) between 2007 and 2021. The study population was divided into two groups according to the position of the reduced twin (presenting or non-presenting) and outcomes were studied accordingly. The primary outcome was a composite of early complications following ST, including infection, preterm prelabor rupture of membranes and pregnancy loss.

RESULTS

A total of 190 dichorionic twin pregnancies were included, of which 73 underwent ST of the presenting twin and 117 of the non-presenting twin. The groups did not differ in either baseline demographic characteristics or mean gestational age at the time of the procedure. ST of the presenting twin resulted in a significantly higher rate of early complications compared with the non-presenting twin (19.2% vs 7.7%; P = 0.018). Moreover, the rates of preterm delivery (75.3% vs 37.6%; P < 0.001) and neonatal intensive care unit admission (45.3% vs 17.1%; P < 0.001) were higher, and birth weight was lower (P < 0.001), in those pregnancies in which the presenting twin was reduced.

CONCLUSIONS

ST of the presenting twin resulted in a higher rate of adverse pregnancy outcome compared with that of the non-presenting twin. These findings should be acknowledged during patient counseling and, if legislation permits, taken into consideration when planning ST. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Clinical practice guidelines for the antenatal management of dichorionic diamniotic twin pregnancies: a systematic review

OBJECTIVE

This review aimed to identify guidelines with recommendations applicable to the antenatal management of dichorionic diamniotic twin pregnancies within high-income countries, appraise their methodological quality, and discuss the similarities and variability across guidelines.

METHOD

A systematic literature review of electronic databases was performed. Manual searches of guideline repositories and websites of professional organisations were performed to identify additional guidelines. The protocol for this systematic review was registered on PROSPERO (CRD42021248586, 25 June 2021). AGREE II and AGREE-REX tools were applied to assess the quality of eligible guidelines. A narrative and thematic synthesis described and compared the guidelines and their recommendations.

RESULTS

Twenty-four guidelines were included, from which 483 recommendations were identified across 4 international organisations and 12 countries. Guidelines addressed eight themes and recommendations were classified accordingly: chorionicity and dating (103 recommendations), fetal growth (105 recommendations), termination of pregnancy (12 recommendations), fetal death (13 recommendations), fetal anomalies (65 recommendations), antenatal care (65 recommendations), preterm labour (56 recommendations) and birth (54 recommendations). Guidelines showed significant variability in recommendations, with conflicting recommendations regarding non-invasive preterm testing, definitions surrounding selective fetal growth restriction, screening for preterm labour and the timing of birth. Guidelines lacked a focus on standard antenatal management of DCDA twins, management of discordant fetal anomaly and single fetal demise.

CONCLUSIONS

Specific guidance for dichorionic diamniotic twins is overall indistinct and access to guidance regarding the antenatal management of these pregnancies is currently difficult. Management of discordant fetal anomaly or single fetal demise needs greater consideration.

Neonatal and developmental outcomes of very preterm twins according to the chorionicity and weight discordance

Perinatal outcomes of twin pregnancies are determined by several factors, such as gestational age (GA), chorionicity, and discordance at birth. This retrospective study aimed to investigate the association of chorionicity and discordance with neonatal and neurodevelopmental outcomes in preterm twin infants from uncomplicated pregnancy. Data of very preterm twin infants who were both live-born between 2014 and 2019 on the chorionicity of the twin, diagnosis of the twin-to-twin syndrome (TTTS), weight discordance at birth, and neonatal and neurodevelopmental outcomes at 24 months of corrected age (CA) were collected. Of the 204 twin infants analyzed, 136 were dichorionic (DC) and 68 were monochorionic (MC), including 15 pairs with TTTS. After adjusting for GA, brain injury, including severe intraventricular hemorrhage and periventricular leukomalacia, was mostly found in the MC with TTTS group, with a higher incidence of cerebral palsy and motor delay at CA 24 months. After excluding TTTS, multivariable analysis showed no association between chorionicity and neonatal and developmental outcomes, whereas small infants among co-twins (adjusted odds ratio (aOR) 3.33, 95% confidence interval 1.03-10.74) and greater discordance (%) of weight at birth (aOR 1.04, 1.00-1.07) were associated with neurodevelopmental impairment. Monochorionicity might not determine adverse outcomes among very preterm twins from uncomplicated pregnancy.

Survival Status, Length of Stay, and Predictors of Mortality Among Neonates Admitted in the Neonatal Intensive Care Unit of Gurage Zone Public Hospitals

Background

Many countries need to accelerate their progress to achieve the sustainable development goal target of neonatal death. It is still high in Ethiopia. Thus, this study aimed to assess the mortality predictors and length of hospital stay among Neonates admitted to the Neonatal Intensive Care Unit of Gurage zone public Hospitals.

Method

In this study, a facility-based retrospective follow-up study was applied among 375 neonates admitted to the NICU of selected public hospitals in the Gurage zone from June 1, 2019 to June 30, 2021. The researchers used Epi-Data entry 3.1 for the data entry and then exported it to STATA version 14 for analysis. The Kaplan-Meier survival curve and log-rank test were used to estimate and compare the survival time of categorical variables, respectively.

Result

The researchers observed about 85 (22.7% with 95%CI: 18.7, 27.2) deaths from the 2305 person-days follow-up. The median survival time was 14 days. The overall incidence density rate was 36.9 per 1000 person-days observed (95%CI: 29.8, 45.6). Perinatal asphyxia (AHR: 2.9[CI: 1.8; 4.8]), cesarean section as a mode of delivery (AHR: 1.1[CI; 1.01; 1.15]), maternal age of greater or equal to 35 years (AHR: 1.1[95% CI: 1.01, 1.15]), and twin pregnancy (AHR: 2.3[95% CI: 1.2, 4.3]) were predictors of neonatal mortality.

Conclusion

The survival rate of neonates was higher compared to other studies. So, to reduce the burden of neonatal mortality, health care providers should give special attention to twin pregnancies, neonates delivered via cesarean section, and neonates with a problem of perinatal asphyxia.

Short-term neonatal and long-term infant outcome of late-preterm twins: nationwide population-based study

OBJECTIVES

To evaluate the short- and long-term outcome of late-preterm compared with term birth in twin pregnancy.

METHODS

This retrospective observational cohort study included all women who had a twin delivery between 1 January 2007 and 31 December 2010 recorded in the claims database of the Korea National Health Insurance, with at least one follow-up recorded in the database of the National Health Screening Program for Infants and Children. Outcomes were analyzed at the pregnancy level, with adverse outcome being defined as an adverse outcome in one or both twins, identified by a diagnosis according to the International Classification of Diseases 10^th Revision. The primary short-term outcome was composite morbidity, which included any of the following: transient tachypnea, respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage and bronchopulmonary dysplasia. Long-term adverse outcome included any neurological or neurodevelopmental outcome, defined by prespecified neurological and developmental diagnoses; these were assessed by following up all neonates until the end of 2018, by which time they were 8-11 years of age. Outcomes were compared between twins delivered late preterm (34 + 0 to 36 + 6 weeks) and those delivered at term (≥ 37 weeks).

RESULTS

Among 17 189 women who delivered twins at ≥ 34 weeks of gestation during the study period, 5032 (29.27%) women delivered in the late-preterm period. On multivariate analysis, compared with the twins delivered at term, the late-preterm twins had an increased risk for the primary short-term outcome of composite morbidity (adjusted odds ratio (aOR), 2.09; 95% CI, 1.90-2.30), including transient tachypnea (aOR, 1.85; 95% CI, 1.64-2.09), respiratory distress syndrome (aOR, 2.31; 95% CI, 2.04-2.62), necrotizing enterocolitis (aOR, 2.10; 95% CI, 1.20-3.69) and intraventricular hemorrhage (aOR, 2.13; 95% CI, 1.46-3.11). For the long-term outcome, the late-preterm twins also had an increased risk for any neurological or neurodevelopmental outcome (adjusted hazard ratio, 1.14; 95% CI, 1.07-1.21).

CONCLUSIONS

Twins delivered in the late-preterm period have an increased risk for short- and long-term morbidity compared with twins delivered at term. These results should be considered when determining the timing of delivery in uncomplicated twin pregnancy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Development of a Nomogram for Clinical Risk Prediction of Preterm Neonate Death in Ethiopia

Introduction

In 2020, over 6,500 newborn deaths occured every day, resulting in 2.4 million children dying in their 1st month of life. Ethiopia is one of the countries that will need to step up their efforts and expedite progress to meet the 2030 sustainable development goal. Developing prediction models to forecast the mortality of preterm neonates could be valuable in low-resource settings with limited amenities, such as Ethiopia. Therefore, the study aims to develop a nomogram for clinical risk prediction of preterm neonate death in Ethiopia in 2021.

Methods

A prospective follow-up study design was employed. The data were used to analyze using R-programming version 4.0.3 software. The least absolute shrinkage and selection operator (LASSO) regression is used for variable selection to be retained in the multivariable model. The model discrimination probability was checked using the ROC (AUROC) curve area. The model's clinical and public health impact was assessed using decision curve analysis (DCA). A nomogram graphical presentation created an individualized prediction of preterm neonate risk of mortality.

Results

The area under the receiver operating curve (AUROC) discerning power for five sets of prognostic determinants (gestational age, respiratory distress syndrome, multiple neonates, low birth weight, and kangaroo mother care) is 92.7% (95% CI: 89.9-95.4%). This prediction model was particular (specificity = 95%) in predicting preterm death, with a true positive rate (sensitivity) of 77%. The best cut point value for predicting a high or low risk of preterm death (Youden index) was 0.3 (30%). Positive and negative predictive values at the Youden index threshold value were 85.4 percent and 93.3 percent, respectively.

Conclusion

This risk prediction model provides a straightforward nomogram tool for predicting the death of preterm newborns. Following the preterm neonates critically based on the model has the highest cost-benefit ratio.

Incidence of small-for-gestational-age infant birthweight following early intertwin fetal growth discordance in dichorionic and monochorionic twin pregnancies

BACKGROUND

Serial growth scans are routinely recommended for twin pregnancies to identify fetal growth restriction (defined as an estimated fetal weight of <10th percentile), which can result in increased perinatal morbidity and mortality. However, the clinical significance of early intertwin growth discordance in the absence of fetal growth restriction remains unclear.

OBJECTIVE

This study aimed to compare the rates of small-for-gestational-age infants among twin pregnancies with intertwin growth discordance in the absence of fetal growth restriction with that among twin pregnancies with concordant, normal growth identified by ultrasound between 24 0/7 and 31 6/7 weeks' gestation.

STUDY DESIGN

This was a retrospective cohort study of twin deliveries at a single hospital from 2010 to 2019. Pregnancies without fetal growth restriction were categorized as discordant or concordant using the earliest prenatal growth ultrasound between 24 0/7 and 31 6/7 weeks' gestation. Discordance was defined as an estimated fetal weight difference of ≥18% between twins. Pregnancies with major fetal anomalies, no growth ultrasound between 24 0/7 and 31 6/7 weeks' gestation, or twin-twin transfusion syndrome were excluded. The cohort was stratified by chorionicity. Our primary outcome was small-for-gestational-age defined as <10th percentile per the Fenton growth curve at delivery. Secondary outcomes included gestational age at delivery, mode of delivery, neonatal intensive care unit admission, length of stay, and neonatal complications and placental pathology.

RESULTS

Of the 707 twin pregnancies that met the inclusion criteria, 558 (79%) were dichorionic and 149 (21%) were monochorionic. Most pregnancies were concordant on ultrasound between 24 0/7 and 31 6/7 weeks' gestation (dichorionic, 93%; monochorionic, 87%). Regardless of chorionicity, twin pregnancies with discordance at ultrasound, were more likely to have a small-for-gestational-age infant than concordant twin pregnancies (dichorionic: 51% vs 29%; P=.002; monochorionic: 65% vs 24%; P<.001). Furthermore, women with twin pregnancies with discordance were delivered at an earlier gestational age (dichorionic: 36 weeks [interquartile range, 33-36] vs 34 weeks [interquartile range, 34-38]; P<.001; monochorionic: 34 weeks [interquartile range, 32-34] vs 36 weeks [interquartile range, 34-37]; P=.003). Pregnancies with growth discordance were more likely to be delivered by cesarean delivery (dichorionic: 90% vs 72%; P=.01; monochorionic: 65% vs 60%; P=.70), although this was only statistically significant for dichorionic twin pregnancies. Neonates of pregnancies with growth discordance had a higher incidence of respiratory distress syndrome (dichorionic: 54% vs 37%; P=.04; monochorionic: 70% vs 45%; P=.04) and neonatal intensive care unit admission (dichorionic: 71% vs 50%; P=.01; monochorionic: 90% vs 65%; P=.03). Furthermore, dichorionic infants had longer neonatal intensive care unit stays (30 [interquartile range, 18-61] vs 18 [interquartile range, 10-35] days; P=.02).

CONCLUSION

Regardless of chorionicity, twin pregnancies with discordance without fetal growth restriction identified on growth ultrasound between 24 0/7 and 31 6/7 weeks' gestation were nearly twice as likely to develop small-for-gestational-age neonates, deliver earlier in gestation, and experience greater neonatal morbidity than twin pregnancies without discordance. Patients with pregnancies complicated by isolated intertwin discordance between 24 0/7 and 31 6/7 weeks' gestation will need counseling regarding adverse perinatal outcomes.

Should twin-specific growth charts be used to assess fetal growth in twin pregnancies?

One of the hallmarks of twin pregnancies is the slower rate of fetal growth when compared with singleton pregnancies during the third trimester. The mechanisms underlying this phenomenon and whether it represents pathology or benign physiological adaptation are currently unclear. One important implication of these questions relates to the type growth charts that should be used by care providers to monitor growth of twin fetuses. If the slower growth represents pathology (ie, intrauterine growth restriction caused uteroplacental insufficiency), it would be preferable to use a singleton growth chart to identify a small twin fetus that is at risk for perinatal mortality and morbidity. If, however, the relative smallness of twins is the result of benign adaptive mechanisms, it is likely preferable to use a twin-based charts to avoid overdiagnosis of intrauterine growth restriction in twin pregnancies. In the current review, we addressed this question by describing the differences in fetal growth between twin and singleton pregnancies, reviewing the current knowledge regarding the mechanisms responsible for slower fetal growth in twins, summarizing available empirical evidence on the diagnostic accuracy of the 2 types of charts for intrauterine growth restriction in twin pregnancies, and addressing the question of whether uncomplicated dichorionic twins are at an increased risk for fetal death when compared with singleton fetuses. We identified a growing body of evidence that shows that the use of twin charts can reduce the proportion of twin fetuses identified with suspected intrauterine growth restriction by up to 8-fold and can lead to a diagnosis of intrauterine growth restriction that is more strongly associated with adverse perinatal outcomes and hypertensive disorders than a diagnosis of intrauterine growth restriction based on a singleton-based chart without compromising the detection of twin fetuses at risk for adverse outcomes caused by uteroplacental insufficiency. We further found that small for gestational age twins are less likely to experience adverse perinatal outcomes or to have evidence of uteroplacental insufficiency than small for gestational age singletons and that recent data question the longstanding view that uncomplicated dichorionic twins are at an increased risk for fetal death caused by placental insufficiency. Overall, it seems that, based on existing evidence, the of use twin charts is reasonable and may be preferred over the use of singleton charts when monitoring the growth of twin fetuses. Still, it is important to note that the available data have considerable limitations and are primarily derived from observational studies. Therefore, adequately-powered trials are likely needed to confirm the benefit of twin charts before their use is adopted by professional societies.

Prevalence and outcomes of twin pregnancies in Botswana: a national birth outcomes surveillance study

OBJECTIVES

This study aims to evaluate the prevalence and outcome of twin pregnancies in Botswana.

SETTING

The Tsepamo Study conducted birth outcomes surveillance at 8 government-run hospitals (~45% of all births in Botswana) from August 2014 to June 2018 and expanded to 18 hospitals (~70% of all births in Botswana) from July 2018 to March 2019.

PARTICIPANTS

Data were collected for all live-born and stillborn in-hospital deliveries with a gestational age (GA) greater than 24 weeks. This analysis included 117 593 singleton and 3718 twin infants (1859 sets (1.6%)) born to 119 477 women between August 2014 and March 2019 and excluded 73 higher order multiples (23 sets of triplets and 1 set of quadruplets).

OUTCOMES MEASURED

Our primary outcomes were preterm delivery (<37 weeks GA), very preterm delivery (<32 weeks GA) and stillbirth (APGAR (Appearance, Pulse, Grimace, Activity, Respiration) score of 0, 0, 0).

RESULTS

Women with twin pregnancies had a similar median number of antenatal care visits (9 vs 10), but were more likely to deliver in a tertiary centre (54.8% vs 45.1%, p<0.001) and more likely to have a cesarean-section (54.6% vs 22.0%, p<0.001) than women with singletons. Compared with singletons, twin pregnancies had a higher risk of preterm delivery (<37 weeks GA) (47.6% vs 16.7%, adjusted risk ratio (aRR) 2.8, 95% CI 2.7 to 2.9) and very preterm delivery (<32 weeks) (11.8% vs 4.0%, aRR 3.0 95% CI 2.6 to 3.4). Among all twin pregnancies, 128 (6.9%) had at least one stillborn infant compared with 2845 (2.4%) stillbirths among singletons (aRR 2.8, 95% CI 2.3 to 3.3).

CONCLUSION

Adverse birth outcomes are common among twins in Botswana, and are often severe. Interventions that allow for earlier identification of twin gestation and improved antenatal management of twin pregnancies may improve infant and child survival.

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.

Prospective risk of stillbirth and neonatal complications for monochorionic diamniotic and dichorionic diamniotic twins after 24 weeks of gestation

INTRODUCTION

Our study compared the prospective risks of intrauterine fetal death (IUFD), neonatal death (NND), perinatal death (PND), and neonatal morbidities in monochorionic diamniotic (MCDA) and dichorionic diamniotic (DCDA) twin pregnancies.

METHODS

This retrospective cohort study included twin pregnancies who had antenatal care and delivery in a public hospital from 2011 to 2018. Exclusion criteria included monoamnionicity, one/both twin miscarriage, twin-twin transfusion syndrome, or lethal congenital abnormalities. All twins were managed in multiple pregnancy clinic with standardized protocols. Gestational age-specific IUFD, NND, PND, and neonatal morbidity rates were compared according to chorionicity.

RESULTS

Three hundred seventy-eight MCDA and 1282 DCDA twins were included. MCDA twins had higher risks of PND (1.9% vs. 0.7% in DCDA twins, p = 0.05), composite neonatal morbidity (p = 0.01), preterm delivery (p < 0.01), and low birth weight (p < 0.01). The prospective risk of IUFD was 0.6% and 0.4% for MCDA and DCDA twins, respectively after 34 weeks' gestation. No NND occurred among deliveries after 30 weeks. The risk of neonatal morbidity of MCDA twins fell from 22.7% at 34 weeks to 2.7% at 37 weeks (p < 0.01). For DCDA twins, the risk of morbidity fell insignificantly from 36 to 38 weeks (4.0% vs. 3.4%, p = 0.60). Logistic regression analysis suggested that the increased risk of perinatal morbidities was related to the higher rate of preterm delivery in MCDA twins rather than chorionicity.

CONCLUSION

With close fetal monitoring, the risk of late IUFD in twin pregnancies without major complications is low. Perinatal morbidity can be minimized by avoiding late preterm deliveries in twin pregnancies.

The mystery of monozygotic twinning II: What can monozygotic twinning tell us about Amyoplasia from a review of the various mechanisms and types of monozygotic twinning?

Monozygotic (MZ) twins ("identical twins") are essentially unique to human beings. Why and how they arise is not known. This article reviews the possible different types of MZ twinning recognized in the previous article on twins and arthrogryposis. There appear to be at least three subgroups of MZ twinning: spontaneous, familial, and those related to artificial reproductive technologies. Each is likely to have different etiologies and different secondary findings. Spontaneous MZ twinning may relate to "overripe ova." Amyoplasia, a specific nongenetic form of arthrogryposis, appears to occur in spontaneous MZ twinning and may be related to twin-twin transfusion.

Spontaneous septostomy in a monochorionic-diamniotic twin gestation

Monochorionic twin gestations are associated with a greater incidence of neonatal morbidity and mortality when compared with their dichorionic counterparts. In turn, monochorionic-monoamniotic (MCMA) gestations carry greater risks compared with monochorionic-diamniotic (MCDA) gestations. While the true incidence of spontaneous septostomy of the dividing membranes (SSDM) in MCDA twins is unknown, SSDM has been demonstrated to be associated with increased morbidity and mortality, due to functional transition from a MCDA gestation to a MCMA gestation. We report a case of SSDM in a mid-trimester MCDA gestation, review the literature, and describe how to identify and manage this complication.

Maternal age is associated with embryo splitting after single embryo transfer: a retrospective cohort study

PURPOSE

To determine whether maternal age has an impact on monozygotic twinning (MZT) rates in women undergoing single embryo transfer (SET).

METHODS

This is a retrospective cohort study analyzed for the incidence of MZT of all clinical pregnancies after a single embryo transfer was carried out between 2014 and 2018. The effect of different assisted reproductive technology (ART) parameters on the incidence of MZT was evaluated.

RESULTS

There were a total of 8459 cycles resulting in pregnancy during the study period. Of these pregnancies, 8236 were singletons and 223 were MZT. The preterm birth rate, miscarriage rate, and cesarean section rate were higher in MZT. Birth weight and gestational age at delivery were lower and smaller. In the univariate analysis, the risk of MZT was decreased with frozen embryo transfer (ET). A nonlinear relationship was observed between maternal age and MZT. A negative relationship between maternal age and MZT was observed in the patients' age ≥ 36 years.

CONCLUSION

Advanced maternal age was associated with a lower rate of MZT. A threshold female age of 36 years existed for lower MZT.

Association between chorionicity and preterm birth in twin pregnancies: a systematic review involving 29 864 twin pregnancies

BACKGROUND

The perinatal mortality and morbidity among twins vary by chorionicity. Although it is considered that monochorionicity is associated with an increased risk of preterm birth in twin pregnancies, no systematic review exists evaluating this association.

OBJECTIVES

This systematic review was undertaken to assess the association between preterm birth and chorionicity in twin pregnancies.

SEARCH STRATEGY

We searched the electronic databases from January 1990 to July 2019 without language restrictions.

SELECTION CRITERIA

All studies on twin pregnancies where chorionicity and preterm birth were evaluated were included.

DATA COLLECTION AND ANALYSIS

Findings are reported as odds ratios with 95% confidence intervals. The estimates are pooled using random-effects meta-analysis.

MAIN RESULTS

From 13 156 citations, we included 39 studies (29 864 pregnancies). Monochorionicity was significantly associated with increased risk of preterm birth at ≤28, ≤32, ≤34 and <37 weeks in women asymptomatic and symptomatic for preterm labour (odds ratio [OR] 2.14, 95% CI 1.52-3.02, I²  = 46%, OR 1.55, 95% CI 1.27-1.89 I²  = 68%, OR 1.47, 95% CI 1.27-1.69, I²  = 60%, OR 1.66, 95% CI 1.43-1.93, I²  = 65%, respectively). Among those asymptomatic for preterm labour, significantly increased odds of preterm birth were seen for monochorionicity at gestations ≤34 weeks (OR 1.85, 95% CI 1.42-2.40, I²  = 25%) and <37 weeks (OR 1.75, 95% CI 1.22-2.53, I²  = 61%). Sensitivity analysis showed significantly increased odds of spontaneous preterm birth at ≤34 and <37 weeks for monochorionicity (OR 1.25, 95% CI 1.01-1.55, I²  = 0% and OR 1.41, 95% CI 1.13-1.78, I²  = 0%).

CONCLUSIONS

Monochorionicity is significantly associated with preterm birth at all gestations.

TWEETABLE ABSTRACT

In twin pregnancies, monochorionicity is associated with an increased risk of preterm birth at all gestations.

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.

The Kaplan Meier estimates of mortality and its predictors among newborns admitted with low birth weight at public hospitals in Ethiopia

BACKGROUND

Globally, every year greater than twenty million newborns are born weighing less than 2500grams, of which over 96% of them were in developing countries. It contributes to sixty to eighty percent of all neonatal deaths, annually. These infants weighing less than 2500gram will have a poor immune system and are at risk of morbidity and mortality. This study was aimed to investigate the survival status and predictors of mortality among neonates admitted with low birth weight at public hospitals in Ethiopia.

METHOD

A prospective cohort study was conducted among selected 216 newborns admitted with low birth weight who were admitted in neonatal intensive care unit at Arba Minch General hospital, Sawla General Hospital and Chencha district hospital from 1st March 2018 to 28st February 2019. Data were entered into Epi data version 3.02 and exported to STATA V 14 for analysis. The Kaplan Meier survival curve together with log rank test was used to estimate the survival time of the newborns. Variables which had p-value <0.05 in multivariable analysis using the cox proportional hazard model were declared as statistically significant.

RESULT

The cumulative proportion of surviving at the end of third days was 99.01% (95%CI: 96.11, 99.75). Similarly it was 97.81% (95%CI: 94.25, 99.18), 96.27% (95%CI: 91.76, 98.33) and 94.33% (95%CI: 88.72, 97.19) at the end of fourth, fifth and sixth day respectively. The overall mean survival time was 17.13 days (95%CI: 12.76, 21.49). The incidence of mortality among neonates admitted with low birth weight was 83 per 1000 live births. Mothers with DM (AHR:4.79; 95%CI:1.15, 19.8), maternal HIV infection(AHR:6.47;95%CI:1.43,29.3), not keeping the newborn under KMC(AHR:13.0;95%CI:3.42, 49.5) and initiating exclusive breast feeding within one hour(AHR:0.19;95%CI:0.04, 0.95) were statistically significant in multivariable cox regression analysis.

CONCLUSION

The risk of mortality among neonates admitted with low birth weight was high at the early admission period and the incidence of mortality was high. Maternal history of diabetes mellitus, HIV/AIDS infection, keeping the newborn under kangaroo mother care and exclusive breast feeding initiation were statistically significant predictors of mortality. Special emphasis should be given for neonates with low birth weight at the early follow up periods and Kangaroo mother care practice should be a usual practice.

Comparison of spontaneous fetal loss rates between women with singleton and twin pregnancies after mid-trimester amniocentesis - A historical cohort study

OBJECTIVE

To assess and compare fetal loss rates before 28 weeks of singleton and twin pregnancies after mid-trimester amniocentesis.

METHOD

This historic cohort study included 13 773 women with singletons and 426 women with twins undergoing mid-trimester amniocentesis from 1/2015 to 3/2017. Pregnancies resulting in termination or selective reduction before 28 weeks were excluded, as well as twin gestations undergoing single-puncture amniocentesis. Fetal loss rates were compared between singleton and twins taking into account maternal characteristics, amniocentesis procedure, and fetal chromosomal abnormalities.

RESULTS

The rates of fetal chromosomal abnormalities were similar in singleton and twin gestations (1.13% vs 0.70%, P = .253). No difference was found in maternal or fetal characteristics, or amniocentesis procedure between the two groups. The fetal loss rate was significantly higher in twin compared with singleton pregnancies (1.91% vs 0.24%, P < .001, RR = 8.25 [95% CI: 4.51 to 15.09]). The fetal loss rate between monochorionic twins and dichorionic twins was similar (1.80% vs 1.78%, P = 1.000).

CONCLUSIONS

Twin pregnancies have higher risk of fetal loss after mid-trimester amniocentesis, which cannot be explained by differences in rates of fetal chromosomal abnormalities, maternal characteristic, or amniocentesis technique.

Twin Pregnancies, Crown-rump Length and Birthweight Discordancy: The Influence of Chorionicity

OBJECTIVE

 The purpose of the present study was to analyze the influence of chorionicity in the biometric parameters crown-rump length (CRL), birthweight (BW), crown-rump length discordancy (CRLD) and birthweight discordancy (BWD), determine the correlation between these latter two in cases of intertwin discordancy, and to analyze the influence of chronicity in the presence of these discordancies with clinical relevance (> 10% and > 15%, respectively).

METHODS

 The present study was a retrospective study based on the twin pregnancy database of the Centro Hospitalar S. João (2010-2015), including 486 fetuses among 66 monochorionic (MC) and 177 dichorionic gestations (DC). The inclusion criteria were multiple pregnancies with 2 fetuses and healthy twin gestations. The exclusion criteria were trichorionic gestations and pregnancies with inconclusive chorionicity, multiple pregnancy with ≥ 3 fetuses and pathological twin gestations.

RESULTS

 No statistically significant difference was found in BW (p = 0.09) and in its discordancy (p = 0.06) nor in CRL (p = 0.48) and its discordancy (p = 0.74) between MCs and DCs. Crown-rump length discordancy and birthweight discordancy were correlated by the regression line "BWD = 0.8864 x CRLD + 0.0743," with r²  = 0.1599. Crown-rump length discordancy > 10% was found in 7.58% of monochorionic and in 13.56% of dichorionic twins. Birthweight discordancy > 15% was detected in 16.67% of monochorionic and in 31.64% of dichorionic twins.

CONCLUSION

 No statistically significant influence of chorionicity was identified in both birthweight and birthweight discordancy, as in crown-rump length and crown-rump length discordancy. Birthweight discordancy was correlated to crown-rump length discordancy in 20% of cases.

Neurodevelopmental outcome of preterm twins at 5 years of age

BACKGROUND

Twins are considered to be at an increased risk for perinatal mortality and morbidities, but it is unclear whether preterm twins are at an increased risk for poor developmental outcomes when compared to preterm singletons. Our aim was to compare the neurodevelopmental outcome of preterm twins vs singletons at 5 years of age.

METHODS

Very low birth weight and very low gestational age infants (twins n = 66, singletons n = 157) were recruited as a part of the PIPARI project in the Turku University Hospital, covering a regional population. Cognitive development, neuropsychological performance, and neurodevelopmental impairments (including cerebral palsy, hearing deficit, visual impairment, and intellectual disability) were evaluated at 5 years of age.

RESULTS

Twins and singletons had otherwise similar perinatal background factors, except for the higher proportion of preterm rupture of membranes in singletons. Twins had cognitive and neuropsychological outcomes that were otherwise comparable with singletons, but they had a slightly lower verbal intelligence quotient (estimate -5.81, 95% CI -11.14 to -0.48, p = 0.03). Being a twin was not a risk for neurodevelopmental impairments.

CONCLUSIONS

Our study shows that, contrary to a common hypothesis, the overall neurodevelopment of very preterm twins does not significantly differ from that of preterm singletons.

Magnitude and Risk of Dying among Low Birth Weight Neonates in Rural Ethiopia: A Community-Based Cross-Sectional Study

BACKGROUND

Even if remarkable progress has been made in reducing preventable child deaths worldwide, neonatal mortality reduction has remained unsatisfactory. Low birth weight (LBW) is the major risk factor for child deaths during the neonatal period, yet only 5% of babies are weighed at birth in Ethiopia. The aim of the present study was to determine the magnitude and risk of dying among low birth weight neonates in rural Gedeo, Southern Ethiopia.

METHODS

Community-based mixed-method approach design was employed between September and October 2016 to identify and enroll study participants in rural Gedeo, Southern Ethiopia. Records of 17,503 live birth babies, of whom 2,065 (11.8%) had LBW, born in the last 12 months were screened to identify 885 (42.8%) biological mother-LBW neonate pairs from eight health centers. The study subjects were randomly selected using a multistage stratified cluster sampling technique. Cox proportional hazards regression model was used to predict maternal and neonatal risk factors associated with the risk of neonatal death.

RESULTS

The overall neonatal mortality rate (NMR) among LBW infants was 110 per 1000 live births (95% confidence interval: 75 -228). Close to half, 374 (42.3%), of the LBW neonates died during the first week of life. The estimated hazard ratios of mortality were higher among neonates whose mothers did not attend antenatal care (ANC) (HR=1.58, 95 % CI: 1.02-2.43), gave birth by assisted or cesarean delivery (HR=1.81 and 3.72; 95% CI: 1.10 - 3.02 and 2.11-6.55), and experienced some form of illness during pregnancy (HH=3.34, 95 % CI: 2.11-5.29), respectively. Similarly, neonates born with very low (<2000gm) birth weight and born prematurely (before 37 weeks of gestation) carried a higher (HR= 1.90 and 1.47; 95 % CI: 1.22 - 2.96 and 1.07-2.28) risk of death. On the other hand, maternal formal education was found to be the single protective factor (HR= 0.65,95 % CI: 0.43-0.99).

CONCLUSION

Nearly one in every ten (11%) of neonates die before celebrating their firth month of life, mainly during the first week in rural Ethiopia. The risk of dying from LBW during the neonatal period is almost fourfold of the current estimated national NMR. Maternal obstetric characteristics and fetal maturity were predictors of mortality.

Comparison of neonatal outcomes of very low birth weight infants by mode of conception: in vitro fertilization versus natural pregnancy

OBJECTIVE

To compare the neonatal outcomes of very low birth weight (VLBW) infants born after IVF with those of VLBW infants born after natural pregnancy (NP).

DESIGN

Prospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 6,871 VLBW infants born from January 2014 to December 2016.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Neonatal mortality and morbidities.

RESULT(S)

Of the 6,871 VLBW infants enrolled, 4,438 infants were born as singletons (IVF = 271; NP = 4,167), and 2,433 infants were born as multiplets (IVF = 1,301; NP = 1,132). After adjustment for maternal and neonatal baseline characteristics, infants born as singletons earlier than 28 weeks after IVF more frequently had high-stage retinopathy of prematurity than those born after NP, whereas infants born as multiplets between 28 and 31 weeks after IVF had fewer major congenital anomalies, high-grade intraventricular hemorrhage, and periventricular leukomalacia than those born after NP. Otherwise, no differences in mortality and neonatal outcomes were found.

CONCLUSION(S)

Very low birth weight infants born as singletons after IVF had comparable neonatal outcomes to those born after NP, except for an increased risk of high-stage retinopathy of prematurity. Very low birth weight infants born as multiplets after IVF had fewer neurologic morbidities than those born after NP.

Prevalence, antenatal management and perinatal outcome of monochorionic monoamniotic twin pregnancy: a collaborative multicenter study in England, 2000-2013

OBJECTIVES

To determine the prevalence of monochorionic monoamniotic (MCMA) twin pregnancy and to describe perinatal outcome and clinical management of these pregnancies.

METHODS

In this multicenter cohort study, the prevalence of MCMA twinning was estimated using population-based data on MCMA twin pregnancies, collected between 2000 and 2013 from 11 Northern Survey of Twin and Multiple Pregnancy (NorSTAMP) maternity units. Pregnancy outcome at < 24 weeks' gestation, antenatal parameters and perinatal outcome (from ≥ 24 weeks to the first 28 days of age) were analyzed using combined data on pregnancies confirmed to be MCMA from NorSTAMP and the Southwest Thames Region of London Obstetric Research Collaborative (STORK) multiple pregnancy cohort for 2000-2013.

RESULTS

The estimated total prevalence of MCMA twin pregnancies in the North of England region was 8.2 per 1000 twin pregnancies (59/7170), and the birth prevalence was 0.08 per 1000 pregnancies overall (singleton and multiple). Using combined data from NorSTAMP and STORK, the rate of fetal death (at < 24 weeks' gestation), including terminations of pregnancy and selective feticide, was 31.8% (54/170); the overall perinatal mortality rate was 14.7% (17/116), ranging from 69.2% at < 30 weeks to 4.5% at ≥ 33 weeks' gestation. MCMA twins that survived in utero beyond 24 weeks were delivered, usually by Cesarean section, at a median of 33 (interquartile range, 32-34) weeks of gestation.

CONCLUSIONS

In MCMA twins surviving beyond 24 weeks of gestation, there was a higher survival rate compared with in previous decades, presumably due to early diagnosis, close surveillance and elective birth around 32-34 weeks of gestation. High perinatal mortality at early gestations was attributed mainly to extreme prematurity due to preterm spontaneous labor. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Early demise of twins in a cohort of stillbirths and second trimester miscarriages

Twins, particularly monochorionic (MC) pairs, are at increased risk for fetal death. Whereas previous work has sought to understand the mechanisms for this increased mortality, most studies analyze viable twin pregnancies or liveborn twin cohorts. In the Wisconsin Stillbirth Service Program cohort of 3,137 stillbirths and second trimester miscarriages, we identified 175 twin pregnancies for a twinning rate of 56/1,000, which is approximately double the general population. The excess of twins among miscarriages and stillbirths was attributable to MC pairs as the incidence of dizygotic (DZ) twinning was not increased compared to livebirth data. The leading causes of fetal demise among twins were twin-twin transfusion, acardia, and twin-twin disruption. Maternal causes of death, primarily premature rupture of membranes, were moderately increased in both MC and DZ twins relative to singletons. Although deceased twins were smaller than expected for viable twins at comparable gestational ages, placenta weights of deceased MC pairs were large compared to combined fetal weight, which indicates placental inefficiency likely due to vascular shunting. Co-twin survival was much lower for MC than for DZ pairs. Therefore, earlier diagnosis and treatment of MC twinning complications may decrease prenatal mortality.

Falling perinatal mortality in twins in the UK: organisational success or chance?

In June 2018, Mothers and Babies Reducing Risks through Audits and Confidential Enquiries across the UK (MBRRACE-UK) published a Perinatal Surveillance report of an audit between 2013-2016. This noted that the stillbirth rate for twins nearly halved between 2014-2016; whereas the stillbirth rate for singletons remained static. There was a statistically significant reduction in the rate of stillbirth in twins over this period from 11.07 (95% CI, 9.78-12.47) to 6.16 (95% CI, 5.20-7.24) per 1000 total births. This commentary discusses these observations, the effects of twin chorionicity, and the potential obstetric and neonatal interventions, as well as public health improvements, that may have influenced these findings.

Ultrasound surveillance in twin pregnancy: An update for practitioners

Ultrasound has revolutionised the management of multiple pregnancies and their complications. Increasing frequency of twin pregnancies mandates familiarity of all clinicians with the relevant pathologies and evidence-based surveillance and management protocols for their care. In this review, we summarise the latest evidence relating to ultrasound surveillance of twin pregnancies including first trimester assessment and screening, growth surveillance and the detection and management of the complications of monochorionic pregnancies including twin-to-twin-transfusion syndrome, selective fetal growth restriction, twin reversed arterial perfusion sequence and conjoined twinning.

The Effect of Twin Birth on Neonatal and Infant Mortality Rates: A Systematic Review

Background and aims: Twin birth may account for higher mortality rates in infants and neonates. To investigate the potential relationship between twin birth and infant and neonatal mortality rates (NMRs), a systematic review was conducted. Methods: To gather the evidence for the relationship between twin birth and its potential effect on mortality during infancy and neonatal periods, a systematic review was conducted. The most important used databases were PubMed, Google Scholar, Web of Science, Scopus, ProQuest, Cochrane and Springer. Then, the databases were searched by appropriate keywords. After reviewing and evaluating the collected studies, trends in the different countries were compared. Results: A total of 13 790 related studies were found, of which 128 studies were selected in the first step. The studies which were not related to the subject, in addition to repetitive studies, were excluded from the search in the second step based on inclusion and exclusion criteria by reviewing the abstract and, in some cases, the full article. Finally, 7 studies entered the last step. Conclusion: This study showed that the mortality could be higher among twins than among non-twins, especially among boys.

Early neonatal mortality in twin pregnancy: Findings from 60 low- and middle-income countries

Background

Around the world, the incidence of multiple pregnancies reaches its peak in the Central African countries and often represents an increased risk of death for women and children because of higher rates of obstetrical complications and poor management skills in those countries. We sought to assess the association between twins and early neonatal mortality compared with singleton pregnancies. We also assessed the role of skilled birth attendant and mode of delivery on early neonatal mortality in twin pregnancies.

Methods

We conducted a secondary analysis of individual level data from 60 nationally-representative Demographic and Health Surveys including 521 867 singleton and 14 312 twin births. We investigated the occurrence of deaths within the first week of life in twins compared to singletons and the effect of place and attendance at birth; also, the role of caesarean sections against vaginal births was examined, globally and after countries stratification per caesarean sections rates. A multi-level logistic regression was used accounting for homogeneity within country, and homogeneity within twin pairs.

Results

Early neonatal mortality among twins was significantly higher when compared to singleton neonates (adjusted odds ratio (aOR) 7.6; 95% confidence interval (CI) = 7.0-8.3) in these 60 countries. Early neonatal mortality was also higher among twins than singletons when adjusting for birth weight in a subgroup analysis of those countries with data on birth weight (n = 20; less than 20% of missing values) (aOR = 2.8; 95% CI = 2.2-3.5). For countries with high rates (>15%) of caesarean sections (CS), twins delivered vaginally in health facility had a statistically significant (aOR = 4.8; 95% CI = 2.4-9.4) increased risk of early neonatal mortality compared to twins delivered through caesarean sections. Home twin births without SBA was associated with increased mortality compared with delivering at home with SBA (aOR = 1.3; 95% CI = 1.0-1.8) and with vaginal birth in health facility (aOR = 1.7; 95% CI = 1.4-2.0).

Conclusions

Institutional deliveries and increased access of caesarian sections may be considered for twin pregnancies in low- and middle- income countries to decrease early adverse neonatal outcomes.

Influence of chorionicity and gestational age at single fetal loss on risk of preterm birth in twin pregnancy: analysis of STORK multiple pregnancy cohort

OBJECTIVE

Single intrauterine death (sIUD) in twin pregnancy is associated with a significant risk of cotwin demise and preterm birth (PTB), especially in monochorionic (MC) twins. However, it is yet to be established whether the gestational age at loss may influence the pregnancy outcome. The aim of this study was to explore the risk of PTB according to the gestational age at diagnosis of sIUD.

METHODS

This was a cohort study of all twin pregnancies booked for antenatal care in a large regional network of nine hospitals over a 10-year period. Ultrasound data were matched to hospital delivery records and to a mandatory national register for stillbirth and neonatal loss provided by the Centre for Maternal and Child Enquires. Cases with double fetal loss at the time of the scan and cases of sIUD occurring at or after 34 weeks of gestation were not included in the analysis. The relative risk (RR) of PTB at < 34, < 32 and < 28 weeks of gestation in twin pregnancies complicated by sIUD was assessed and compared with that in twin pregnancies without fetal loss. The risk of PTB at < 34 weeks was stratified according to the gestational age at diagnosis of sIUD. The risk of PTB in twin pregnancy after sIUD according to the gestational age at death was also explored.

RESULTS

The analysis included 3013 twin gestations (2469 dichorionic (DC) and 544 MC). Median gestational age at birth was lower in the pregnancies complicated by sIUD compared with those that were not (32.0 weeks: interquartile range (IQR), 29.0-34.3 weeks vs 36.7 weeks: IQR, 35.0-37.6; P < 0.001) and this difference persisted when stratifying the data according to chorionicity (P < 0.0001 for both MC and DC pregnancies). The risk of PTB at < 34 weeks (RR, 4.3 (95% CI, 3.5-5.2)), < 32 weeks (RR, 6.1 (95% CI, 4.6-8.1)) and < 28 weeks (RR, 12.4 (95% CI, 6.9-22.2)) of gestation was higher in pregnancies complicated by sIUD compared with those which did not experience fetal loss. This association was observed both in MC and DC twin gestations. When compared with DC pregnancies, MC twins affected by sIUD were not at significantly increased risk of PTB before either 34, 32 or 28 weeks of gestation. The risk of PTB at < 34 weeks of gestation was higher when the sIUD occurred at a later gestational age (chi-square test for trend, P < 0.001).

CONCLUSIONS

Twin pregnancies complicated by sIUD, regardless of the chorionicity, have a significantly higher risk of PTB at < 34, < 32 and < 28 weeks of gestation. The risk of PTB at < 34 weeks of gestation was higher when the sIUD occurred in the second half of the pregnancy. Large prospective multicenter studies with shared protocols for prenatal management are needed to ascertain the actual risk of spontaneous PTB in twin pregnancies affected by sIUD. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Twin-twin transfusion and laser therapy

PURPOSE OF REVIEW

Twin-to-twin transfusion syndrome (TTTS) is an uncommon, but dangerous, complication of monochorionic diamniotic twin gestations. The purpose of this review is to provide an update on the evolving treatments in TTTS as it pertains primarily to laser photocoagulation, as well as to provide recently published information on outcomes.

RECENT FINDINGS

The Solomon laser technique, in which selective fetoscopic laser photocoagulation is first performed and then followed by laser of the vascular equator from one side of the placenta to the other, reduces TTTS complications of twin anemia-polycythemia syndrome and recurrent TTTS. The addition of fetal echocardiography to the historical staging of TTTS adds important information that may guide future therapies. The postlaser ablation rate of neurodevelopmental delay in TTTS has recently been reported to be 14%. Cotwin demise is a significant complication of untreated TTTS and survival carries a 25% risk of cystic periventricular leukomalacia, middle cerebral artery infarction, and injury to other central nervous system structures as noted by neuroimaging.

SUMMARY

Laser therapy for TTTS is clearly the only therapy that halts the disease process, allows both fetuses an opportunity to survive and protects a surviving cotwin in the event of the demise of one twin. Laser techniques have evolved greatly over the last 25 years and recent reports with the addition of the Solomon technique appearing to reduce some postlaser complications (twin anemia-polycythemia sequence and recurrent TTTS). Future focus of TTTS therapy should be centered on understanding the pathophysiology of the disease better with improvement in staging of the disease and on comparison of different laser techniques with the overall goal of not only increasing twin survival rates but also reducing long term neurodevelopmental morbidity.

All-Cause Mortality of Low Birthweight Infants in Infancy, Childhood, and Adolescence: Population Study of England and Wales

BACKGROUND

Low birthweight (LBW) is associated with increased mortality in infancy, but its association with mortality in later childhood and adolescence is less clear. We investigated the association between birthweight and all-cause mortality and identified major causes of mortality for different birthweight groups.

METHODS AND FINDINGS

We conducted a population study of all live births occurring in England and Wales between 1 January 1993 and 31 December 2011. Following exclusions, the 12,355,251 live births were classified by birthweight: 500-1,499 g (very LBW [VLBW], n = 139,608), 1,500-2,499 g (LBW, n = 759,283), 2,500-3,499 g (n = 6,511,411), and ≥3,500 g (n = 4,944,949). The association of birthweight group with mortality in infancy (<1 y of age) and childhood/adolescence (1-18 y of age) was quantified, with and without covariates, through hazard ratios using Cox regression. International Classification of Diseases codes identified causes of death. In all, 74,890 (0.61%) individuals died between birth and 18 y of age, with 23% of deaths occurring after infancy. Adjusted hazard ratios for infant deaths were 145 (95% CI 141, 149) and 9.8 (95% CI 9.5, 10.1) for the VLBW and LBW groups, respectively, compared to the ≥3,500 g group. The respective hazard ratios for death occurring at age 1-18 y were 6.6 (95% CI 6.1, 7.1) and 2.9 (95% CI 2.8, 3.1). Male gender, the youngest and oldest maternal age bands, multiple births, and deprivation (Index of Multiple Deprivation score) also contributed to increased deaths in the VLBW and LBW groups in both age ranges. In infancy, perinatal factors, particularly respiratory issues and infections, explained 84% and 31% of deaths in the VLBW and LBW groups, respectively; congenital malformations explained 36% and 23% in the LBW group and ≥2,500 g groups (2,500-3,499 g and ≥3,500 g groups combined), respectively. Central nervous system conditions explained 20% of deaths in childhood/adolescence in the VLBW group, with deaths from neoplasms and external conditions increasingly prevalent in the 1,500-2,499 g and ≥2,500 g birthweight groups. The study would have benefited had we had access to information on gestational age and maternal smoking, but since the former is highly correlated with birthweight and the latter with deprivation, we believe that our findings remain robust despite these shortcomings.

CONCLUSIONS

LBW is associated with infant and later child and adolescent mortality, with perinatal factors and congenital malformations explaining many of the deaths. By understanding and ameliorating the influences of upstream exposures such as maternal smoking and deprivation, later mortality can be decreased by reducing the delivery of vulnerable infants with LBW.

Pregestational diabetes is associated with adverse outcomes in twin pregnancies: a regional register-based study

INTRODUCTION

The incidence of pregnancies complicated by twinning and diabetes is increasing in the UK. This is a worrying trend as both diabetes and twin gestations are associated with a high risk of adverse pregnancy outcomes. The few studies that have specifically addressed how twinning and pregestational diabetes in the same pregnancy may affect outcome have reported conflicting results.

MATERIAL AND METHODS

We analyzed data on 27 women with a twin pregnancy and pregestational diabetes (54 babies) and 6407 women with a twin pregnancy without diabetes (12 814 babies) from the Northern Survey of Twin and Multiple Pregnancy during 1998-2010. A composite adverse pregnancy outcome (comprising fetal loss before 24 weeks, termination of pregnancy, stillbirth, infant death or any major congenital anomaly), extended perinatal mortality (stillbirths and neonatal deaths) and major congenital anomaly were the main outcome measures. Adjusted rate ratios were estimated using generalized estimating equations for Poisson regression controlling for potential confounders.

RESULTS

Mothers with twin pregnancies with diabetes were older (p = 0.001) and had higher body mass indices (p < 0.0001) than those without diabetes. Their twins were more likely to be delivered earlier (p = 0.026), be delivered by cesarean section (80.4% vs. 49.7%; p < 0.0001), be large-for-gestational-age (p < 0.0001) and require admission to a special care baby unit (p < 0.0001). Pregestational diabetes was associated with significantly increased rates of the composite adverse outcome and major congenital anomalies in twins (adjusted rate ratios 2.66, 95% confidence interval 1.14-6.20 and adjusted rate ratios 3.51, 95% confidence interval 1.31-9.40, respectively).

CONCLUSION

Maternal pregestational diabetes in twin pregnancies is associated with a significantly increased risk of an adverse pregnancy outcome.

Clustering of monozygotic twinning in IVF

PURPOSE

The aim of this analysis was to study whether monozygotic twinning (MZT) events occur in clusters after IVF and, if so, to explore possible explanations for this clustering.

METHODS

This is a retrospective cohort study carried out in a single, large university-affiliated reproductive medicine practice. Medical records of all patients who had undergone fresh IVF cycles, resulting in a viable clinical pregnancy, from Jan 2002 to Dec 2013 were reviewed. The incidence of MZT in 6-month intervals and the association with independent risk factors such as maternal age, extended embryo culture, PGD/intracytoplasmic sperm injection (ICSI)/assisted hatching performed were analyzed.

RESULTS

Over the 12-year study period, 25,502 fresh IVF cycles were performed, resulting in 8598 clinical pregnancies. Ninety-five cycles (1.1 %) resulted in MZ twins. The percentage of MZT was >2 standard deviations (SD) higher than the overall percentage of MZT in 4 of the 24 6-month intervals. PGD, extended embryo culture (≥4 days), and more recent cycles (2005 or later) were independent risk factors for MZT. The use of multivariable logistic regression modeling to control for risk factors for MZT did not correct for this clustering effect, with both high-risk interval (clustering) and extended embryo culture remaining significant.

CONCLUSION

This study supports our hypothesis that MZT occurs in clusters and that this clustering effect could not be explained by demographics and cycle characteristics alone. Although we are unable to explain the clustering phenomenon, this study is important as it highlights high-risk intervals for MZT and opens the door to performing a more detailed investigation, to identify the mechanisms responsible for the spikes of MZT incidence.

Insights from physiology into myometrial function and dysfunction

NEW FINDINGS

What is the topic of this review? I focus on clinical aspects of uterine physiology, specifically, myometrial contractility. I bring together and contrast findings using physiological approaches and those using newer techniques, 'omics'. What advances does it highlight? Physiological studies have recently shed light on the myometrium in twin pregnancies, but there have been no 'omic' approaches. In contrast, studies of preterm delivery using newer approaches are generating new research avenues, whereas traditional approaches have not flourished. Finally, I describe significant advances in understanding of 'slow-to-progress' labours, achieved using physiological and clinical approaches. Advances in molecular, genetic and 'omic' technologies are fuelling the thirst for better understanding of the uterus and application of this information to problems in pregnancy and labour. Progress has, however, been limited while we still have an incomplete understanding of some of the basic physiology of uterine smooth muscle (myometrium). In this review and opinion piece, I explore some of the fascinating findings from selected recent studies and see how these may provide new avenues for physiological and clinical research. It is also the case, however, that there is still limited mechanistic understanding about physiological and pathophysiological processes in the myometrium. This lack of understanding limits the usefulness of some findings from genomic and allied studies. By focusing on some key recent findings and relating these to two important clinical problems in childbirth that involve myometrial activity, namely preterm delivery and difficult labours, the interplay between our physiological knowledge and the information provided by newer technologies is explored. My opinion is that physiology has provided much more new mechanistic insight into difficult births and that the newer technologies may lead to breakthroughs in preterm birth research, but that this has not yet happened.

The impact of chorionicity on maternal pregnancy outcomes

OBJECTIVE

Women carrying twin pregnancies often receive similar counseling, regardless of chorionicity, with the notable exception of twin-twin transfusion syndrome (TTTS); however, little is known about whether the presence of 1 vs 2 placentas confers dissimilar maternal risks. We sought to determine differences in maternal and neonatal outcomes based on chorionicity.

STUDY DESIGN

This was a retrospective cohort study of all twin pregnancies at our institution undergoing routine second-trimester ultrasound for anatomic survey from 1990 through 2010. Secondary outcomes included other adverse maternal and neonatal outcomes. Relative risks and adjusted odds ratios (aORs) were calculated. Cluster analysis was used to account for nonindependence of twin pairs.

RESULTS

Of 2301 pregnancies, 1747 (75.9%) were dichorionic and 554 (24.1%) were monochorionic. Rates of preeclampsia, gestational diabetes, placental abruption, placenta previa, preterm labor, and preterm premature rupture of membranes (PPROM) were not significantly different in dichorionic vs monochorionic pregnancies. Early preterm delivery less than 34 weeks (aOR, 1.47; 95% confidence interval [CI], 1.17-1.86) and less than 28 weeks (aOR, 2.58; 95% CI, 1.58-4.20) were more likely in monochorionic twins, as was neonatal intensive care unit admission (aOR, 1.41; 95% CI, 1.12-1.78). Monochorionic twins delivered earlier at a mean gestational age of 34.2 weeks vs 35.0 weeks for dichorionic twins (P < .001). Hospital length of stay was significantly longer for monochorionic twins with a mean of 13.7 days vs 10.8 days for dichorionic twins (P = .01).

CONCLUSION

There are no significant differences in maternal outcomes by chorionicity; however, monochorionicity is associated with increased fetal risks. This information may be helpful in guiding more targeted counseling to expectant parents of twins that, although the presence of an additional placenta does not confer additional maternal risks, monochorionic infants tend to deliver earlier and require longer hospital stays.

The North American Fetal Therapy Network Consensus Statement: prenatal management of uncomplicated monochorionic gestations

Owing to vascular connections within a single placenta, monochorionic gestations present distinctive prenatal management challenges. Complications that can arise as a result of unbalanced hemodynamic exchange (twin-twin transfusion syndrome and twin anemia polycythemia sequence) and unequal placental sharing (selective fetal growth restriction) should be kept in mind while prenatal management is being planned. Because of unique monochorionic angioarchitecture, what happens to one twin can directly affect the other. Death of one twin can result in death or permanent disability of the co-twin. Early detection of these unique disease processes through frequent ultrasonographic surveillance may allow the opportunity for earlier referral, intervention, or both and potentially better outcomes. Therefore, monochorionic gestations should be managed differently than dichorionic gestations or singletons. The purpose of this document is to present in detail methods for monitoring and management of uncomplicated monochorionic gestations and to review the evidence for the roles of these methods for detection of complications in clinical practice. Finally, we present evidence-based and expert opinion-supported recommendations developed by the North American Fetal Therapy Network for the diagnosis, surveillance, and delivery of uncomplicated monochorionic gestations.

Mothers' perspectives on the perinatal loss of a co-twin: a qualitative study

BACKGROUND

There is a growing body of literature exploring the emotional impact of perinatal loss upon parents but only limited research focussing specifically on the views and experiences of parents who have experienced a loss from a twin or higher order pregnancy. We undertook a qualitative study to provide an in-depth understanding of the experiences of mothers who have had a loss from a twin pregnancy and subsequently continued visiting hospital whilst their surviving twin was cared for.

METHODS

A qualitative study involving semi-structured interviews. Mothers were recruited from a Neonatal Intensive Care Unit and Fetal Medicine department. Fourteen interviews were carried out with mothers who had experienced a loss in pregnancy or the neonatal period and had a surviving twin on the neonatal unit. Data were analysed using a generative thematic approach.

RESULTS

The analysis identified three key themes in the accounts mothers gave of their experiences: the status of 'special'; the importance of trust; and control and empowerment. Where the surviving co-twin remained in hospital for many weeks, mothers described the emotional support of health professionals as crucial to their wellbeing. Few mothers sought formal bereavement support, instead they kept their grief 'on hold' in order to support their surviving baby. Due to the trauma of their loss, mothers reflected that they had been unable to make informed decisions, in particular in relation to the funeral of their deceased baby.

CONCLUSIONS

Our study highlighted that there are a specific set of issues for mothers who have lost a baby from a twin pregnancy. Relatively small changes to practice however, made a significant difference to wellbeing during their time in hospital with a surviving twin. Findings from this research will provide insight into the needs of bereaved mothers, will inform healthcare planning and the development of care packages.

Twin Birth Considering the Current Results of the "Twin Birth Study"

The rate of caesarean sections in multiple births has grown sharply worldwide. The reason for this may be the results of large retrospective cohort studies from the 1990s, which displayed an increased risk of mortality and morbidity, especially for the second twin, in the case of vaginal births. Multiple monocentric analyses have not been able to confirm this. As a prospective, multi-centre randomised study, the Twin Birth Study published in 2013, in which 105 clinics in 25 countries took part, showed that, under optimum conditions, there was no difference in neonatal and maternal mortality and morbidity if the birth was planned to be vaginal or via caesarean. Detailed analyses, which would be helpful in choosing the type of birth method and obstetric management in the event of vaginal birth, have not previously been published. Retrospective studies must be referred to for this.