Maternal physiology and complications of multiple pregnancy

Guideline No. 450: Care of Pregnant Women Living with HIV and Interventions to Reduce Perinatal Transmission

OBJECTIVE

This guideline provides an update on the care of pregnant women living with HIV and the prevention of perinatal HIV transmission. This guideline is a revision of the previous guideline, No. 310 Guidelines for the Care of Pregnant Women Living With HIV and Interventions to Reduce Perinatal Transmission, and includes an updated review of the literature with contemporary recommendations.

TARGET POPULATION

Pregnant women newly diagnosed with HIV during antenatal screening and women living with HIV who become pregnant. This guideline does not include specific guidance for girls/women of reproductive age living with HIV who are not pregnant.

OUTCOMES

Prevention of perinatal HIV transmission is a key indicator of the success of a health care system and requires multidisciplinary care of pregnant women living with HIV. Intended outcomes include guidance on best practice in perinatal management for Canadian health care providers for pregnant women living with HIV; reduction of perinatal transmission of HIV toward a target of eradication of perinatal transmission; provision of optimal antenatal care for pregnant women to ensure the best maternal health outcomes and HIV suppression; and evidence-based support and recommendations for pregnant women living with HIV, maintaining awareness and consideration of the complex psychosocial impacts of living with HIV.

BENEFITS, HARMS, AND COSTS

The perinatal transmission of HIV has significant morbidity and mortality implications for the child, with associated lifelong health care costs. Pregnancy presents an emotionally and physically vulnerable time for pregnant women as well as an opportunity to engage them in health promotion. This guidance does not include recommendations with additional costs to health care facilities compared with the previous guideline. Application of the recommendations is aimed at health benefits to both mother and child by optimizing maternal health and preventing perinatal HIV transmission.

EVIDENCE

Published and unpublished literature was reviewed with a focus on publications post-2013. OVID-Medline, Embase, PubMed and the Cochrane Library databases were searched for relevant publications available in English or French for each section of this guideline. Results included systematic reviews, randomized controlled trials, and observational studies published from 2012 to 2022. Searches were updated on a regular basis and incorporated in the guideline until May 2023. Unpublished literature, protocols, and international guidelines were identified by accessing the websites of health-related agencies, clinical practice guideline collections, and national and international medical specialty societies.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional recommendations).

INTENDED AUDIENCE

The intended users of this guideline include obstetric care providers and infectious disease clinicians who provide care for pregnant women living with HIV.

SOCIAL MEDIA SUMMARY

Updated Canadian HIV in pregnancy guideline informed by global research and tailored to Canadian healthcare needs and goals for pregnant women living with HIV and their families.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Is the Early Screening of Lower Genital Tract Infections Useful in Preventing Adverse Obstetrical Outcomes in Twin Pregnancy?

Objectives: Twin pregnancy implies a higher risk of preterm birth and, consequently, higher neonatal morbidity and mortality. In singleton pregnancies, infections of the lower genital tract (LGTIs) and bacterial vaginosis are associated with preterm labor, and their early detection has been proven effective in reducing complications like the preterm premature rupture of membranes (pPROM) and preterm delivery. The same evidence, however, is lacking for twin pregnancies. This study aimed to evaluate whether the early identification and treatment of LGTIs or bacterial vaginosis in asymptomatic women with twin pregnancy could reduce the rate of miscarriages, pPROM, and preterm birth. Methods: This study performed a retrospective comparison of 285 women with a multiple pregnancy submitted for a cervico-vaginal swab only at 20-22 weeks (Single Test Group, STG), and 199 women who underwent the swab at 12-14 and again at 20-22 weeks (Double Test Group, DTG). All women included in the study had a twin pregnancy and were followed up at Sant'Anna Hospital, Turin (Italy), between September 2012 and February 2021. Results: In STG, 21.7% of patients had a positive swab; in DTG, 19.9% had an early positive swab that was immediately treated by targeted antibiotics; and 16.7% had a mid-pregnancy positive swab. The DTG showed a significantly lower incidence of pPROM in univariate analysis (14.4% vs. 23.1%, p = 0.021), which was confirmed by multivariate analysis (OR 0.55, CI 0.33-0.93, p = 0.025). Conclusions: Our study suggests that, in asymptomatic women with twin pregnancy, the early screening of LGTIs and bacterial vaginosis by a cervico-vaginal swab at 12-14 weeks of gestational age is effective in reducing the risk of pPROM.

BlastAssist: a deep learning pipeline to measure interpretable features of human embryos

STUDY QUESTION

Can the BlastAssist deep learning pipeline perform comparably to or outperform human experts and embryologists at measuring interpretable, clinically relevant features of human embryos in IVF?

SUMMARY ANSWER

The BlastAssist pipeline can measure a comprehensive set of interpretable features of human embryos and either outperform or perform comparably to embryologists and human experts in measuring these features.

WHAT IS KNOWN ALREADY

Some studies have applied deep learning and developed 'black-box' algorithms to predict embryo viability directly from microscope images and videos but these lack interpretability and generalizability. Other studies have developed deep learning networks to measure individual features of embryos but fail to conduct careful comparisons to embryologists' performance, which are fundamental to demonstrate the network's effectiveness.

STUDY DESIGN, SIZE, DURATION

We applied the BlastAssist pipeline to 67 043 973 images (32 939 embryos) recorded in the IVF lab from 2012 to 2017 in Tel Aviv Sourasky Medical Center. We first compared the pipeline measurements of individual images/embryos to manual measurements by human experts for sets of features, including: (i) fertilization status (n = 207 embryos), (ii) cell symmetry (n = 109 embryos), (iii) degree of fragmentation (n = 6664 images), and (iv) developmental timing (n = 21 036 images). We then conducted detailed comparisons between pipeline outputs and annotations made by embryologists during routine treatments for features, including: (i) fertilization status (n = 18 922 embryos), (ii) pronuclei (PN) fade time (n = 13 781 embryos), (iii) degree of fragmentation on Day 2 (n = 11 582 embryos), and (iv) time of blastulation (n = 3266 embryos). In addition, we compared the pipeline outputs to the implantation results of 723 single embryo transfer (SET) cycles, and to the live birth results of 3421 embryos transferred in 1801 cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In addition to EmbryoScope™ image data, manual embryo grading and annotations, and electronic health record (EHR) data on treatment outcomes were also included. We integrated the deep learning networks we developed for individual features to construct the BlastAssist pipeline. Pearson's χ2 test was used to evaluate the statistical independence of individual features and implantation success. Bayesian statistics was used to evaluate the association of the probability of an embryo resulting in live birth to BlastAssist inputs.

MAIN RESULTS AND THE ROLE OF CHANCE

The BlastAssist pipeline integrates five deep learning networks and measures comprehensive, interpretable, and quantitative features in clinical IVF. The pipeline performs similarly or better than manual measurements. For fertilization status, the network performs with very good parameters of specificity and sensitivity (area under the receiver operating characteristics (AUROC) 0.84-0.94). For symmetry score, the pipeline performs comparably to the human expert at both 2-cell (r = 0.71 ± 0.06) and 4-cell stages (r = 0.77 ± 0.07). For degree of fragmentation, the pipeline (acc = 69.4%) slightly under-performs compared to human experts (acc = 73.8%). For developmental timing, the pipeline (acc = 90.0%) performs similarly to human experts (acc = 91.4%). There is also strong agreement between pipeline outputs and annotations made by embryologists during routine treatments. For fertilization status, the pipeline and embryologists strongly agree (acc = 79.6%), and there is strong correlation between the two measurements (r = 0.683). For degree of fragmentation, the pipeline and embryologists mostly agree (acc = 55.4%), and there is also strong correlation between the two measurements (r = 0.648). For both PN fade time (r = 0.787) and time of blastulation (r = 0.887), there's strong correlation between the pipeline and embryologists. For SET cycles, 2-cell time (P < 0.01) and 2-cell symmetry (P < 0.03) are significantly correlated with implantation success rate, while other features showed correlations with implantation success without statistical significance. In addition, 2-cell time (P < 5 × 10-11), PN fade time (P < 5 × 10-10), degree of fragmentation on Day 3 (P < 5 × 10-4), and 2-cell symmetry (P < 5 × 10-3) showed statistically significant correlation with the probability of the transferred embryo resulting in live birth.

LIMITATIONS, REASONS FOR CAUTION

We have not tested the BlastAssist pipeline on data from other clinics or other time-lapse microscopy (TLM) systems. The association study we conducted with live birth results do not take into account confounding variables, which will be necessary to construct an embryo selection algorithm. Randomized controlled trials (RCT) will be necessary to determine whether the pipeline can improve success rates in clinical IVF.

WIDER IMPLICATIONS OF THE FINDINGS

BlastAssist provides a comprehensive and holistic means of evaluating human embryos. Instead of using a black-box algorithm, BlastAssist outputs meaningful measurements of embryos that can be interpreted and corroborated by embryologists, which is crucial in clinical decision making. Furthermore, the unprecedentedly large dataset generated by BlastAssist measurements can be used as a powerful resource for further research in human embryology and IVF.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by Harvard Quantitative Biology Initiative, the NSF-Simons Center for Mathematical and Statistical Analysis of Biology at Harvard (award number 1764269), the National Institute of Heath (award number R01HD104969), the Perelson Fund, and the Sagol fund for embryos and stem cells as part of the Sagol Network. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

Not applicable.

Analysis of perinatal risk factors for massive pulmonary hemorrhage in very low birth weight infant: A nationwide large cohort database

OBJECTIVE

To determine perinatal risk factors for Massive pulmonary hemorrhage (MPH) and MPH-caused mortality to guide clinicians in implementing preventive measures at the beginning of life for improving the survival of very low birth weight infant (VLBWIs).

STUDY DESIGN

A total of 13,826 VLBWIs born between 2013 and 2020 in the Korean Neonatal Network database were included.

RESULTS

MPH occurred in 870 (6.3 %) VLBWIs. Among infants with MPH, 162 (18.6 %) VLBWIs died due to MPH. In the multivariate logistic regression analysis, independent risk factors for MPH were identified as small for gestational age, multiple gestation, high CRIB-II score, use of surfactant, and symptomatic patent ductus arteriosus (sPDA) in VLBIWs. Independent risk factors for MPH-caused mortality were identified as multiple gestation in VLBWIs. Receiving a complete course of antenatal corticosteroids (ACS) was found to be a significant independent protective factor for MPH-caused mortality in VLBWIs.

CONCLUSION

Proactive managements for reducing unnecessary use of pulmonary surfactant and for decreasing the risk of sPDA at the beginning of life could be recommended as preventive strategies to reduce the risk of MPH in extremely preterm infants. ACS therapy is highly recommended for women with a high likelihood of giving birth preterm to reduce the risk of mortality caused by MPH.

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.

Surgical-site infection in multifetal cesarean delivery

PURPOSE

The relationship between multifetal cesarean delivery and surgical-site infection (SSI) is unclear. If SSI is more common in multifetal cesareans, adjustment of practices such as antibiotic dosing could be warranted. The purpose of this study was to determine whether patients undergoing multifetal cesarean delivery are more likely to experience SSI than those undergoing singleton cesarean delivery.

METHODS

This was a retrospective cohort study including all cesarean deliveries at a tertiary hospital from 10/1/2009 to 12/28/2018. The primary outcome was rate of SSI in women after multifetal cesarean delivery as compared to those who underwent singleton cesarean delivery. Univariable analysis and multivariable logistic regression were used to assess independent clinical factors associated with SSI in multifetal cesarean deliveries.

RESULTS

34,340 women underwent cesarean delivery during this period. 33,211 were singletons (96.7%), and 1,129 were multifetal (3.3%). There was no difference in the rate of SSI in multifetal gestations (15/1,129, 1.3%) as compared to singletons (493/33,211, 1.5%) (p = 0.670, OR 0.89 [95% CI 0.53, 1.50], aOR 1.06 [95% CI 0.61, 1.84]). Limiting analysis to multifetal deliveries, prolonged rupture of membranes (p < 0.004, OR 5.43 [95% CI 1.49, 19.88]), labor augmentation (p < 0.001, OR 15.84 [1.74, 144.53]), and chorioamnionitis (p < 0.001, OR 15.43 [95% CI 3.11, 76.62]) were more common in women with SSI.

DISCUSSION

SSI is not increased in multifetal cesarean delivery as compared to singleton cesarean delivery. In multifetal cesareans, chorioamnionitis, prolonged rupture of membranes, and labor augmentation were associated with increased odds of SSI.

Anesthetic Management of Cesarean Section in the Case of a Sextuplet Pregnancy and Polycystic Ovarian Syndrome

Cesarean section in a mother with a sextuplet pregnancy is challenging for an anesthesiologist. Several perioperative complications are likely because of the overdistended uterus and associated changes in the mother. We are reporting the case of a woman with a sextuplet pregnancy who came for an emergency cesarean. She also had a background history of polycystic ovarian syndrome (PCOS) and ovulation induction for conception. Early pregnancy was complicated by ovarian hyperstimulation syndrome. She required cervical cerclage in early pregnancy. The emergency cesarean was done as she went into preterm labor and six premature babies were delivered at 29 weeks of gestation. Cesarean was done under spinal anesthesia. Preeclampsia and postpartum hemorrhage complicated the perioperative period.

Traumatic brain injury during pregnancy is associated with increased rate of cesarean section: a nationwide multi-register study in Finland

OBJECTIVE

The literature on the incidence of traumatic brain injury (TBI) during pregnancy is lacking. Furthermore, only studies with small sample size have analyzed the impact of TBI during pregnancy to maternal and fetal outcomes. Thus, we aim to report the incidence of TBIs during pregnancy and study the pregnancy outcomes using nationwide high-quality registers.

METHODS

This nationwide retrospective register-based matched cohort study utilized two national registers. All fertile-aged (15-49 years) women with a TBI hospitalization period during pregnancy were retrieved the Care Register for Health Care. Data were then linked with the data from the National Medical Birth Register (MBR). Propensity score matching was conducted according to maternal age during pregnancy, previous cesarean section (CS), maternal smoking status, maternal body mass index, and maternal gestational diabetes. The matching was conducted using the nearest neighbor methods with a caliber width if 0.15, and with a ratio 1:3 (patients/references). Adverse maternal and fetal outcomes were compared between patient group and reference group using Chi-squared tests.

RESULTS

A total of 392 women having a TBI during pregnancy were found. The control group consisted of 722,497 women without TBI during pregnancy. Of the TBIs occurring during pregnancy, the most common types of TBIs were concussion (S06.0) (n = 359, 91.6%), diffuse traumatic brain injury (S06.2) (n = 11, 2.8%), traumatic subdural hemorrhage (n = 7, 1.8%), and unspecified intracranial injury S06.9 (n = 6, 1.5%). The incidence rates of pregnancies with a TBI have remained similar during pregnancy in Finland, peaking at 0.8 per 1000 pregnancies in 2016. The Chi-squared test showed higher rate for CS among women with TBI than for their matched references (21.4% vs. 15.5%, p = .008). Especially, women with TBI during 3rd trimester had higher rate for CS (29.0 vs. 15.0%, p = .016).

CONCLUSIONS

The main findings of this study were that the incidence rates for TBI during pregnancy have remained similar during our study period (2004-2018). TBI during pregnancy, even a mild one, is associated with an increased rate for CS. Especially, TBI during the 3rd trimester was associated with high rate for CS, but the etiology behind this remains unknown. In addition, we found no evidence of difference in fetal outcomes, such as preterm birth, low birth weight, or need for intensive care unit. Future studies should focus on the indications for elective CS, and reasons for unplanned CS among women with TBI during pregnancy, as these could possibly provide important information on the effects of TBI on the course of childbirth.

Establishment of a model for predicting preterm birth based on the machine learning algorithm

BACKGROUND

The purpose of this study was to construct a preterm birth prediction model based on electronic health records and to provide a reference for preterm birth prediction in the future.

METHODS

This was a cross-sectional design. The risk factors for the outcomes of preterm birth were assessed by multifactor logistic regression analysis. In this study, a logical regression model, decision tree, Naive Bayes, support vector machine, and AdaBoost are used to construct the prediction model. Accuracy, recall, precision, F1 value, and receiver operating characteristic curve, were used to evaluate the prediction performance of the model, and the clinical application of the model was verified.

RESULTS

A total of 5411 participants were included and were used for model construction. AdaBoost model has the best prediction ability among the five models. The accuracy of the model for the prediction of "non-preterm birth" was the highest, reaching 100%, and that of "preterm birth" was 72.73%.

CONCLUSIONS

By constructing a preterm birth prediction model based on electronic health records, we believe that machine algorithms have great potential for preterm birth identification. However, more relevant studies are needed before its application in the clinic.

Noninvasive Evaluation of Fetal Zygosity in Twin Pregnancies Involving a Binary Analysis of Single-Nucleotide Polymorphisms

Twin pregnancy constitutes significant risks for maternal and fetal health, which is usually detected by ultrasound examination at early gestation. However, the imaging-based approach may not accurately identify all twins confounded by practical or clinical variables. The analysis of fetal cell-free DNA in noninvasive prenatal screening assays can completement the ultrasound method for twin detection, which differentiates fraternal or identical twins based on their distinct genotypes. Here, a new noninvasive prenatal screening employing high-coverage next-generation sequencing for targeted nucleotide polymorphisms was developed for detection of zygosity and determination of fetal fraction in twin pregnancies. This method utilizes a binary analysis of both the number and allelic fraction of fetus-specific single-nucleotide polymorphisms to infer the zygosity. In 323 samples collected from 215 singleton, 90 dizygotic, and 18 monozygotic twin pregnancies, all 90 dizygotic twins were correctly detected, with a 100% sensitivity and a 100% specificity. In addition, this method can detect complex pregnancies, such as egg donors, contamination, and twins with complete hydatidiform mole. The fetus-specific fetal fraction change was monitored in nine dizygotic twin pregnancies, which demonstrated highly variable dynamics of fetal cell-free DNA turnover up to 7 weeks after twin reduction. Overall, this study provides a new noninvasive prenatal screening strategy for the accurate identification of twin zygosity and quantification of fetal fraction, which has important clinical implications for the management of twin pregnancies.

Maternal comorbidity and adverse perinatal outcomes in survivors of adolescent and young adult cancer: A cohort study

OBJECTIVE

To evaluate risks of preterm birth (PTB) and severe maternal morbidity (SMM) in female survivors of adolescent and young adult cancer and assess maternal comorbidity as a potential mechanism. To determine whether associations differ by use of assisted reproductive technology (ART).

DESIGN

Retrospective cohort.

SETTING

Commercially insured females in the USA.

SAMPLE

Females with live births from 2000-2019 within a de-identified US administrative health claims data set.

METHODS

Log-binomial regression models estimated relative risks of PTB and SMM by cancer status and tested for effect modification. Causal mediation analysis evaluated the proportions explained by maternal comorbidity.

MAIN OUTCOME MEASURES

PTB and SMM.

RESULTS

Among 46 064 cancer survivors, 2440 singleton births, 214 multiple births and 2590 linked newborns occurred after cancer diagnosis. In singleton births, the incidence of PTB was 14.8% in cancer survivors versus 12.4% in females without cancer (aRR 1.19, 95% CI 1.06-1.34); the incidence of SMM was 3.9% in cancer survivors versus 2.4% in females without cancer (aRR 1.44, 95% CI 1.13-1.83). Cancer survivors had more maternal comorbidities before and during pregnancy; 26% of the association between cancer and PTB and 30% of the association between cancer and SMM was mediated by maternal comorbidities. Tests for effect modification of cancer status on perinatal outcomes by ART were non-significant.

CONCLUSIONS

Preterm birth and SMM risks were modestly increased after cancer. Significant proportions of elevated risks may result from increased comorbidities. ART did not significantly modify the association between adolescent and young adult cancer and adverse perinatal outcomes. The prevention and treatment of comorbidities provides an opportunity to improve perinatal outcomes among cancer survivors.

Gestational Diabetes Mellitus Does Not Worsen Obstetrical and Neonatal Outcomes of Twin Pregnancy

The specific effects of gestational diabetes mellitus (GDM) on twin pregnancy outcomes, which are at high risk per se, are unclear. The present study analyzes outcomes of twin pregnancies complicated by GDM (n = 227) by comparing them with GDM singleton pregnancies (n = 1060) and with twin pregnancies without GDM (n = 1008), all followed up at Sant'Anna Hospital, Turin (Italy), between January 2010 and March 2020. The prevalence of GDM among twin pregnancies (n = 1235) was 18.4%. Compared to GDM singletons, GDM twins had higher rates of preeclampsia (aOR 2.0; 95% CI 1.2-3.8), cesarean section (aOR 7.5; 95% CI 5.2-10.8), and neonatal hypoglycemia (aOR 2.5; 95% CI 1.1-5.3). They had a higher incidence of abnormal 2 h OGTT values (aOR 7.1; 95% CI: 3.2-15.7) and were less likely to require insulin therapy (aOR 0.5; 95% CI: 0.3-0.7). In comparison with twin pregnancies without GDM, women with GDM twins were significantly older (35.0 vs. 33.0 years; p < 0.001) and had higher BMI (23.0 versus 22.0 kg/m²; p < 0.001); they had a higher incidence of LGA newborns (aOR 5.3; 95% CI 1.7-14.8), and lower incidence of low APGAR scores (0.5; 95% CI 0.3-0.9). Overall, GDM does not worsen outcomes of twin pregnancy, which is per se at high risk for adverse outcomes.

Online mindfulness-based intervention for women with pregnancy distress: A randomized controlled trial

BACKGROUND

Pregnancy distress among childbearing women is common and can negatively affect both mother and infant. Mindfulness-based interventions (MBIs) may have a positive effect on pregnancy distress but randomized controlled trials with sufficient power are lacking. The current study examined the effectiveness of an online self-guided MBI in pregnant women with pregnancy distress.

METHODS

Pregnant women with elevated pregnancy distress levels at 12 weeks of pregnancy, measured with the Edinburgh Depression Scale (EDS) and Tilburg Pregnancy Distress Scale negative affect (TPDS-NA), were randomized into an intervention group (online MBI, N = 109) or control group (care as usual, N = 110). The primary outcome was the change in pregnancy distress post-intervention and at eight-weeks-follow-up. Secondary outcomes were mindfulness skills (Three Facet Mindfulness Questionnaire-Short Form), rumination (Rumination-Reflection Questionnaire), and self-compassion (Self-Compassion Scale-Short Form) at post-intervention and follow-up in the intervention group.

RESULTS

Significant improvements were found in pregnancy distress scores, but no significant differences between intervention and control group appeared. The MBI group showed improvements in mindfulness skills, rumination, and self-compassion.

LIMITATIONS

Low adherence to the intervention and assessment of secondary outcome measures in the intervention group only.

CONCLUSIONS

An intervention trial with one of the largest samples (N = 219) provided no evidence of a significant effect of an online self-guided MBI in distressed pregnant women. An online MBI may be associated with an improvement in mindfulness skills, rumination, and self-compassion. Future research should address the effectiveness of MBI's with different formats (online and group-based combined) and examine a possible delayed effect.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03917745, registered on 4 March 2019.

Different pathways for preterm birth between singleton and twin pregnancies: a population-based registry study of 481 176 nulliparous women

OBJECTIVE

To explore the contribution of pregnancy-related complications on the prevalence of extremely, very and late preterm births in singleton and twin pregnancies. To study the risk of spontaneous preterm birth in twin pregnancies compared with singleton pregnancies.

DESIGN

Population-based registry study.

SETTING

Medical birth registry of Norway and Statistics Norway.

POPULATION

Nulliparous women with singleton (n = 472 449) or twin (n = 8727) births during 1999-2018.

METHODS

Prevalence rates of pregnancy-related complications for extremely, very and late preterm birth in twin and singleton pregnancies were calculated with 95% confidence intervals. Multivariable logistic regression was applied to assess odds ratios for preterm birth, adjusted for obstetric and socio-economic factors.

MAIN OUTCOME MEASURES

Extremely preterm (<28⁺⁰  weeks of gestation), very preterm (28⁺⁰ -33⁺⁶  weeks of gestation) and late preterm (34⁺⁰ -36⁺⁶  weeks of geatation) birth.

RESULTS

Preterm birth was significantly more prevalent in twin pregnancies than in singleton pregnancies in all categories: all preterm (54.7% vs 6.1%), extremely preterm (3.6% vs 0.4%), very preterm (18.2% vs 1.4%) and late preterm (33.0% vs 4.3%) births. Stillbirth, congenital malformation and pre-eclampsia were more prevalent in twin pregnancies than in singleton pregnancies, but the prevalence of complications differed in the three categories of preterm birth. Pre-eclampsia was more prevalent in singleton than in twin pregnancies ending in extremely and very preterm birth. The adjusted odds of spontaneous preterm live birth were between 19- and 54-fold greater in twin pregnancies than in singleton pregnancies.

CONCLUSIONS

Singleton and twin pregnancies seem to have different pathways leading to extremely, very and late preterm birth.

Adverse obstetric outcomes in women with PCOS and multiple gestations

RESEARCH QUESTION

Does multiple gestation alter the risks for adverse obstetric outcomes in women with polycystic ovary syndrome (PCOS)?

DESIGN

Retrospective population-based cohort study using data from the HCUP-NIS from 2004 to 2014. A total of 14,882 women with PCOS, who delivered within that time period, were identified. The study group comprised women with PCOS who had had a multiple gestation (n = 880); the reference group was comprised of the remaining women with PCOS and singleton gestation (n = 14,002).

RESULTS

In women with PCOS, multiple gestation increased the risks of pregnancy complications including pregnancy-induced hypertension (adjusted odds ratio [aOR] 2.030; 95% confidence interval [CI] 1.676-2.460), pre-eclampsia (aOR 2.879; 95% CI 2.277-3.639), pre-eclampsia and eclampsia superimposed on pre-existing hypertension (aOR 1.917; 95% CI 1.266-2.903) and gestational diabetes (aOR 1.358; 95% CI 1.114-1.656). Multiple gestation increases the risk of preterm premature rupture of membranes (aOR 5.807; 95% CI 4.153-8.119), preterm delivery (aOR 8.466; 95% CI 7.071-10.135), Caesarean section (aOR 5.146; 95% CI 4.184-6.329), post-partum haemorrhage (aOR 1.540; 95% CI 1.065-2.228) and the need for transfusion (aOR 3.268; 95% CI 2.010-5.314), as well as wound complications (aOR 3.089; 95% CI 1.647-5.794). Neonates born to mothers with PCOS and having multiple gestations are more likely to be small for gestational age when compared to singleton neonates born to mothers with PCOS (aOR 4.606; 95% CI 3.480-6.095). Among PCOS women with multiple gestations, obesity increased the risks of developing pregnancy-induced hypertension (P < 0.001), pre-eclampsia (P < 0.001) and wound complications (P = 0.045).

CONCLUSION

These results highlight the importance of single embryo transfer and ovulation induction to develop a single follicle in women with PCOS. Obesity further increases obstetrical complications.

Obstetrics and perinatal outcomes between elective single versus double blastocyst transfer in women younger than 35 years: A cross-sectional study

INTRODUCTION

Clinicians have a positive attitude towards multiple embryo transfer in in vitro fertilization (IVF) cycles, considering increased live birth rates compared to single embryo transfer. We aimed to evaluate obstetric and perinatal outcomes among young women who became clinically pregnant after single & double blastocyst transfer.

MATERIAL-METHOD

545 women under 35 years who became clinically pregnant after fresh blastocyst transfer was evaluated retrospectively. The participants were divided¹according to the transferred embryo number - the elective single blastocyst transfer group (eSBT) (n=112) and the double blastocyst transfer group (DBT group) (n=433). Obstetric and perinatal outcomes were recorded.

RESULTS

Live birth and abortion rates per pregnancy and per gestational sac, having a fetus with congenital anomaly per pregnancy and per neonate, and gestational complications were comparable between the groups. Multiple pregnancy, Cesarean section, and admission to neonatal intensive care unit (NICU) and hospitalization day in NICU per neonate were higher in the DBT group than in the eSBT group. Mean gestational week, birth weight, birth height decreased with the embryo transfer number.

CONCLUSION

DBT transfer appears to be associated with increased multiple pregnancies, Cesarean section, prematurity, decreased fetal anthropometric measurements, and admission to NICU without an increase in live birth and abortion rates. Therefore, it will be easier for clinicians to choose eSBT by providing young couples undergoing IVF treatment with detailed information about multiple pregnancies and prematurity.

Screening Accuracy of the 50 g-Glucose Challenge Test in Twin Compared With Singleton Pregnancies

CONTEXT

The optimal 50 g-glucose challenge test (GCT) cutoff for the diagnosis of gestational diabetes mellitus (GDM) in twin pregnancies is unknown.

OBJECTIVE

This work aimed to explore the screening accuracy of the 50 g-GCT and its correlation with the risk of large for gestational age (LGA) newborn in twin compared to singleton pregnancies. A population-based retrospective cohort study (2007-2017) was conducted in Ontario, Canada. Participants included patients with a singleton (n = 546 892 [98.4%]) or twin (n = 8832 [1.6%]) birth who underwent screening for GDM using the 50 g-GCT.

METHODS

We compared the screening accuracy, risk of GDM, and risk of LGA between twin and singleton pregnancies using various 50 g-GCT cutoffs.

RESULTS

For any given 50 g-GCT result, the probability of GDM was higher (P = .0.007), whereas the probability of LGA was considerably lower in the twin compared with the singleton group, even when a twin-specific growth chart was used to diagnose LGA in the twin group (P < .001). The estimated false-positive rate (FPR) for GDM was higher in twin compared with singleton pregnancies irrespective of the 50 g-GCT cutoff used. The cutoff of 8.2 mmol/L (148 mg/dL) in twin pregnancies was associated with an estimated FPR (10.7%-11.1%) that was similar to the FPR associated with the cutoff of 7.8 mmol/L (140 mg/dL) in singleton pregnancies (10.8%).

CONCLUSION

The screening performance of the 50 g-GCT for GDM and its correlation with LGA differ between twin and singleton pregnancies.

Betamethasone use and risk factors for pulmonary edema during the perinatal period: a single-center retrospective cohort study in Japan

Background

A few studies have reported that maternal administration of antenatal corticosteroids increased the risk of pulmonary edema (PE). However, despite the increasing usage rate of betamethasone as antenatal corticosteroid, maternal administration of betamethasone as a risk factor for PE has not been well studied. This study aimed to evaluate how maternal backgrounds and complications, tocolytic agents, and betamethasone affect the incidence of PE during the perinatal period and determine the risk factor for PE.

Methods

This was a single-center retrospective cohort study in Kurashiki, Japan. The study subjects were patients who had been admitted to our hospital for perinatal management including pregnancy, delivery and puerperium between 2017 and 2020. The primary outcome measure was defined as the incidence of PE during hospitalization. First, in all study subjects, Cox proportional hazards model was used to determine the risk factor for PE during the perinatal period. Next, using propensity score matching, we divided the patients into the betamethasone and betamethasone-free groups and examined the association between betamethasone use and the incidence of PE with Cox proportional hazards model.

Results

During the study period, 4919 cases were hospitalized, and there were 16 PE cases (0.3%). In all analyzed subjects, the occurrence of PE was significantly associated with preeclampsia (hazard ratio 16.8, 95% confidence intervals (CI) 5.39–52.7, P < 0.001) and the combined use of the tocolytic agents such as ritodrine hydrochloride and magnesium sulfate, and betamethasone (hazard ratio 11.3, 95% CI 2.66–48.1, P = 0.001). In contrast, after propensity score matching, no statistically significant difference was found between the betamethasone and betamethasone-free groups in the incidence of PE (hazard ratio 3.19, 95% CI 0.67–15.3, P = 0.145).

Conclusions

A combined use of tocolytic agents and antenatal corticosteroids such as betamethasone may be an independent risk factor for PE during the perinatal period. On the other hand, betamethasone use alone may not be associated with the incidence of PE. When tocolytic agents and betamethasone are administrated to pregnant women, it is important to pay attention to the appearance of maternal respiratory symptoms.

RSV Prevention in All Infants: Which Is the Most Preferable Strategy?

Respiratory syncytial virus (RSV) causes a spectrum of respiratory illnesses in infants and young children that may lead to hospitalizations and a substantial number of outpatient visits, which result in a huge economic and healthcare burden. Most hospitalizations happen in otherwise healthy infants, highlighting the need to protect all infants against RSV. Moreover, there is evidence on the association between early-life RSV respiratory illness and recurrent wheezing/asthma-like symptoms As such, RSV is considered a global health priority. However, despite this, the only prevention strategy currently available is palivizumab, a monoclonal antibody (mAb) indicated in a subset of preterm infants or those with comorbidities, hence leaving the majority of the infant population unprotected against this virus. Therefore, development of prevention strategies against RSV for all infants entering their first RSV season constitutes a large unmet medical need. The aim of this review is to explore different immunization approaches to protect all infants against RSV. Prevention strategies include maternal immunization, immunization of infants with vaccines, immunization of infants with licensed mAbs (palivizumab), and immunization of infants with long-acting mAbs (e.g., nirsevimab, MK-1654). Of these, palivizumab use is restricted to a small population of infants and does not offer a solution for all-infant protection, whereas vaccine development in infants has encountered various challenges, including the immaturity of the infant immune system, highlighting that future pediatric vaccines will most likely be used in older infants (>6 months of age) and children. Consequently, maternal immunization and immunization of infants with long-acting mAbs represent the two feasible strategies for protection of all infants against RSV. Here, we present considerations regarding these two strategies covering key areas which include mechanism of action, "consistency" of protection, RSV variability, duration of protection, flexibility and optimal timing of immunization, benefit for the mother, programmatic implementation, and acceptance of each strategy by key stakeholders. We conclude that, based on current data, immunization of infants with long-acting mAbs might represent the most effective approach for protecting all infants entering their first RSV season.

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.

New approaches suggest term and preterm human fetal membranes may have distinct biomechanical properties

Preterm prelabour rupture of membranes is the leading cause of preterm birth and its associated infant mortality and morbidity. However, its underlying mechanism remains unknown. We utilized two novel biomechanical assessment techniques, ball indentation and Optical Coherence Elastography (OCE), to compare the mechanical properties and behaviours of term (≥ 37 weeks) and preterm (33-36 weeks) human fetal membranes from ruptured and non-ruptured regions. We defined the expression levels of collagen, sulfated glycosaminoglycans (sGAG), matrix metalloproteinase (MMP-9, MMP-13), fibronectin, and interleukin-1β (IL-1β) within membranes by biochemical analysis, immunohistochemical staining and Western blotting, both with and without simulated fetal movement forces on membrane rupture with a new loading system. Preterm membranes showed greater heterogeneity in mechanical properties/behaviours between ruptured and non-ruptured regions compared with their term counterparts (displacement rate: 36% vs. 15%; modulus: 125% vs. 34%; thickness: 93% vs. 30%; collagen content: 98% vs. 29%; sGAG: 85% vs 25%). Furthermore, simulated fetal movement forces triggered higher MMP-9, MMP-13 and IL-1β expression in preterm than term membranes, while nifedipine attenuated the observed increases in expression. In conclusion, the distinct biomechanical profiles of term and preterm membranes and the abnormal biochemical expression and activation by external forces in preterm membranes may provide insights into mechanisms of preterm rupture of membranes.

Mild thrombocytopenia and the risk for postpartum hemorrhage in twin pregnancies

OBJECTIVE

We aimed to investigate the association of mild thrombocytopenia with postpartum hemorrhage (PPH) and blood transfusion among women with twin gestations.

METHODS

A retrospective cohort study (Jan 2015 to May 2019) was performed. Women with twin pregnancies and pre-delivery mild thrombocytopenia were compared to those with normal platelet count. The primary outcome was the rate of PPH, defined as a composite of one or more of the following: (1) need for packed red blood cell transfusion; (2) postpartum hemoglobin decline of ≥3 g/dL; and (3) the use of postpartum uterotonics agents in addition to oxytocin.

RESULTS

Of 1085 women who were included in final analysis, 315 (30.9%) had mild thrombocytopenia (and 770 (69.1%) served as controls. The rate of PPH was increased in the study group (14% vs. 9.4%, P = 0.03), as was the use of uterotonic agents (3.8% vs. 1.3%, respectively, P = 0.02). The rate of blood product transfusion and hemoglobin decline >3 g/dL was not significantly different between the groups. In multivariate logistic regression analysis, mild thrombocytopenia was associated with a higher risk for PPH (OR 1.55 [95% CI 1.02-2.35], P = 0.02).

CONCLUSION

Mild thrombocytopenia in twin pregnancies is associated with an increased risk of interventions such as the use of uterotonic agents.

Clinical Factors and Perinatal Outcomes Associated With Short Latency Period in Twin Pregnancies With Preterm Premature Rupture of Membranes Before 34 Weeks: A Retrospective Study

Background

There is a lack of literature on short latency period (SLP) in twin pregnancies with preterm premature rupture of membranes (PPROM). Thus, the aim of this study was to identify the clinical factors and perinatal outcomes associated with SLP in twin pregnancies with PPROM and to establish a predictive model to identify SLP.

Methods

Twin pregnancies with PPROM between 24 0/7 and 33 6/7 weeks were included and a retrospective analysis was performed. Patients were divided into two groups based on the latency period after PPROM: Group 1 ≤24 h (defined as SLP) and Group 2 >24 h (defined as long latency period, LLP), the clinical factors and perinatal outcomes were compared between the two groups. Binary logistic regression and receiver operating characteristic curve analyses were used to identify the independent clinical factors associated with latency period after PPROM and assess the predictive accuracy for SLP.

Results

98 and 92 pregnant women had short and long latency period, respectively. Prolonged latency significantly increased the occurrence of chorioamnionitis. Neonatal outcomes were not affected by latency duration after PPROM. Binary regression analysis revealed that higher gestational age (GA) at PPROM (P = 0.038), presence of uterine contractions (P < 0.001), Bishop score > 4 (P = 0.030), serum procalcitonin levels ≥0.05 ng/mL upon admission, and absence of use of tocolytic agents (P < 0.001) were significant independent predictors of a SLP. A predictive model developed using these predictors had an area under the curve (AUC) of 0.838, and the presence of uterine contractions alone had an AUC of = 0.711.

Conclusion

Uterine contraction was the most important prognosticator for a SLP. A latency period of >24 h was associated with chorioamnionitis, but adverse neonatal outcomes were not observed.

Perinatal outcomes of twin pregnancies with preterm premature rupture of the membranes at 24-34 weeks' gestation

To describe the perinatal outcomes of twin pregnancies with preterm premature rupture of membranes (PPROM) before 34 weeks’ gestation and identify factors associated with discharge without severe or moderate-severe neonatal morbidity. This study was conducted as a retrospective analysis of twin pregnancies with PPROM occurring at 24 0/7 to 33 6/7 weeks’ gestation. Perinatal outcomes were assessed by gestational age (GA) at PPROM and compared between PPROM and non PPROM twins. Factors associated with discharge without severe or moderate-severe neonatal morbidity were identified using logistic regression analysis. Of the 180 pregnancies (360 foetuses), only 17 (9.4%) women remained pregnant 7 days after PPROM. There were 10 (2.8%) cases of prenatal or neonatal death; 303 (84.2%) and 177 (49.2%) neonates were discharged without severe or moderate-severe morbidity, respectively. As GA at PPROM increased, the adverse obstetric and neonatal outcomes decreased, especially after 32 weeks. There was no significant difference in general neonatal outcomes between PPROM and non PPROM twins. The GA at PPROM and latency period were both significantly associated with discharge without severe or moderate-severe neonatal morbidity. Pregnancy complications and 5-min Apgar score < 7 increased severe neonatal morbidity. As GA at PPROM increased, the risk of adverse perinatal outcomes decreased. GA at PPROM and latency period were significantly associated with discharge without severe or moderate-severe neonatal morbidity.

Acute Myocardial Infarction in a Patient with Twin Pregnancy: A Case Report

INTRODUCTION

Acute myocardial infarction (AMI) rarely occurs during pregnancy and presents unique challenges in diagnosis and management. Traditionally, pregnancy has not readily been considered a risk factor for AMI in the emergency department despite the potential for adverse impacts on maternal and fetal health. As cardiovascular risk factors and advanced maternal age become more prevalent in society over time, the incidence will continue to increase. Prior cases with singular gestation have been reported; however, only one previous case during a twin pregnancy was identified in the medical literature.

CASE REPORT

We describe a rare case of acute ST-segment elevation myocardial infarction in a 37-year-old woman at 24 weeks gestation with a dichorionic diamniotic twin pregnancy.

CONCLUSION

It is important for the emergency physician to recognize acute coronary syndrome as a part of the differential diagnosis of chest pain in pregnant patients and be familiar with the diagnostic and management options available for this special population.

Normal labor curve in twin gestation

BACKGROUND

Failure to progress is one of the leading indications for cesarean delivery in trials of labor in twin gestations. However, assessment of labor progression in twin labors is managed according to singleton labor curves.

OBJECTIVE

This study aimed to establish a partogram for twin deliveries that reflects normal and abnormal labor progression and customized labor curves for different subgroups of twin labors.

STUDY DESIGN

This was a multicenter, retrospective cohort analysis of twin deliveries that were recorded in 3 tertiary medical centers between 2003 and 2017. Eligible parturients were those with twin gestations at ≥34 weeks' gestation with cephalic presentation of the presenting twin and ≥2 cervical examinations during labor. Exclusion criteria were elective cesarean delivery without a trial of labor, major fetal anomalies, and fetal demise. The study group comprised twin gestations, whereas singleton gestations comprised the control group. Statistical analysis was performed using Python 3.7.3 and SPSS, version 27. Categorical variables were analyzed using chi-square tests. Student t test and Mann-Whitney U test were applied to analyze the differences in continuous variables, as appropriate.

RESULTS

A total of 1375 twin deliveries and 142,659 singleton deliveries met the inclusion criteria. Duration of the active phase of labor was significantly longer in twin labors than in singleton labors in both nulliparous and multiparous parturients; the 95th percentile duration was 2 hours longer in nulliparous twin labors and >3.5 hours longer in multiparous twin labors than in singleton labors. The cervical dilation progression rate was significantly slower in twin deliveries than in singleton deliveries with a mean rate in twin deliveries of 1.89 cm/h (95th percentile, 0.51 cm/h) and a mean rate of 2.48 cm/h (95th percentile, 0.73 cm/h) in singleton deliveries (P<.001). In addition, epidural use further slowed labor progression in twin deliveries. The second stage of labor was also markedly longer in twin deliveries, both in nulliparous and multiparous women (95th percentile, 3.04 vs 2.83 hours, P=.002).

CONCLUSION

Twin labors are characterized by a slower progression of the active phase and second stage of labor compared with singleton labors in nulliparous and multiparous parturients. Epidural analgesia further slows labor progression in twin labors. Implementation of these findings in clinical management might lower cesarean delivery rates among cases with protracted labor in twin gestations.

Maternal cardiovascular disease after twin pregnancies complicated by hypertensive disorders of pregnancy: a population-based cohort study

Background:

People whose singleton pregnancy is affected by hypertensive disorders of pregnancy (HDP) are at risk of future cardiovascular disease. It is unclear, however, whether this association can be extrapolated to twin pregnancies. We aimed to compare the association between HDP and future cardiovascular disease after twin and singleton pregnancies.

Methods:

We conducted a population-based retrospective cohort study that included nulliparous people in Ontario, Canada, 1992–2017. We compared the future risk of cardiovascular disease among pregnant people from the following 4 groups: those who delivered a singleton without HDP (referent) and with HDP, and those who delivered twins either with or without HDP.

Results:

The populations of the 4 groups were as follows: 1 431 651 pregnant people in the singleton birth without HDP group; 98 631 singleton birth with HDP; 21 046 twin birth without HDP; and 4283 twin birth with HDP. The median duration of follow-up was 13 (interquartile range 7–20) years. The incidence rate of cardiovascular disease was lowest among those with a singleton or twin birth without HDP (0.72 and 0.74 per 1000 person-years, respectively). Compared with people with a singleton birth without HDP, the risk of cardiovascular disease was highest among those with a singleton birth and HDP (1.47 per 1000 person-years; adjusted hazard ratio [HR] 1.81 [95% confidence interval (CI) 1.72–1.90]), followed by people with a twin pregnancy and HDP (1.07 per 1000 person-years; adjusted HR 1.36 [95% CI 1.04–1.77]). The risk of the primary outcome after a twin pregnancy with HDP was lower than that after a singleton pregnancy with HDP (adjusted HR 0.74 [95% CI 0.57–0.97]), when compared directly.

Interpretation:

In a twin pregnancy, HDP are weaker risk factors for postpartum cardiovascular disease than in a singleton pregnancy.

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.

Gestational Weight Gain in Twin Pregnancies and Maternal and Child Health: An Updated Systematic Review

Background: The Institute of Medicine (IOM) has provisional gestational weight gain (GWG) guidelines for women pregnant with twins due to limited data in this population. To better inform guidelines, the objective of this systematic review was to build on prior work and examine recent data on the associations of GWG with maternal and child health in twin pregnancies. Materials and Methods: In February 2021, Ovid MEDLINE, Embase, CINAHL, and Cochrane Library were searched. Observational studies were eligible if published from January 1, 2013 through February 23, 2021, and examined associations of GWG with maternal or child health outcomes after accounting for gestational age at delivery and pre-pregnancy body mass index. Heterogeneity across studies precluded the use of meta-analytic methods. Results: A total of 29 studies were included. For maternal outcomes, excessive GWG was associated with an increased risk of hypertensive disorders of pregnancy; whereas studies examining gestational diabetes and delivery method reported mixed findings. For child outcomes, inadequate GWG was associated with lower birthweight, small for gestational age, and preterm birth. Adequate or excessive GWG was associated with later gestational age at delivery. Conclusions: This study advances an earlier review by including a more diverse array of maternal and child outcomes. Many of the limitations noted in the original review persist; for example, no studies examined the associations of GWG and outcomes beyond birth. Although it appears that GWG within the IOM guidelines is associated with more optimal outcomes, additional methodologically rigorous studies are needed to better inform evidence-based guidelines.

Risk of Uterine Rupture with Vaginal Birth after Cesarean in Twin Gestations

BACKGROUND

Women with a previous cesarean delivery may attempt a subsequent vaginal birth or repeat cesarean. Vaginal birth after cesarean carries a greater risk of uterine rupture, defined as the disruption of all uterine layers, resulting in maternal-fetal morbidity or mortality. It is unclear how the risk of uterine rupture compares in patients with twin gestations who undergo different delivery methods.

OBJECTIVE

The purpose of this systematic review is to determine if there is an increased risk of uterine rupture in patients with twin gestations attempting vaginal birth after cesarean (VBAC) versus planned repeat cesarean delivery (PRCD). Study Design. PubMed, Cochrane Library, and CINAHL were searched systematically. Eligible studies were prospective and retrospective studies that evaluated the incidence of uterine rupture in twin pregnancies that attempted VBAC or PRCD. Data were manually extracted from these studies, and the number of events in each group was used to calculate an odds ratio (OR) and 95% confidence interval (CI).

RESULTS

4 retrospective studies were included with a total of 7699 participants, 2305 of whom attempted VBAC and 5394 underwent PRCD. The absolute risk of uterine rupture in the VBAC and PRCD groups was 0.87% and 0.09%, respectively. The rate of uterine rupture was significantly higher in the VBAC group than in the PRCD group (OR: 9.43; CI: 3.54-25.17).

CONCLUSION

Although VBAC is associated with higher rates of uterine rupture in twin pregnancies when compared with PRCD, the absolute risk of uterine rupture is low in both groups. Depending on individual risk factors, vaginal birth may be offered as a safe option to women with twin pregnancies and a history of cesarean delivery.

Cardiovascular function during triplet pregnancy

Pregnancy is recognized as a natural physiological stressor to the maternal cardiovascular system. Cardiovascular adaptation is markedly greater in twin pregnancy compared with singleton pregnancy; however, these changes are sparsely documented in triplet pregnancy. The aim of this case series was to compare maternal cardiac function, cardioautonomic regulation, and blood pressure reactivity in healthy singleton, twin, and triplet pregnancies. Resting cardiac structure and function (echocardiography), beat-by-beat blood pressure variability (BPV; photoplethysmography), and heart rate variability (HRV; electrocardiogram) were measured in two triplet, three twin, and three singleton pregnancies (matched for maternal age, prepregnancy body mass index, and gestational age). Hemodynamic responses to a 3-min cold pressor test were also recorded to assess blood pressure reactivity. Due to the small sample size of this case series, statistical comparisons were not made between groups. Compared with singleton and twin pregnancies, individuals pregnant with triplets had greater resting cardiac output but lower cardiac deformation (longitudinal strain, basal circumferential strain, and torsion), sympathetic dominance in cardioautonomic regulation (lower HRV and higher BPV), and elevated blood pressure reactivity in response to the cold pressor test. Taken together, these observations suggest that females with triplet pregnancies may have reduced cardiovascular function, which may contribute to the heightened risk of complications in multifetal pregnancies.NEW & NOTEWORTHY Individuals with healthy triplet pregnancies had greater resting cardiac output but lower left ventricular mechanics when compared with singleton and twin pregnancies matched for gestational age. In addition, triplet pregnancies had greater blood pressure variability and lower overall heart rate variability compared with singleton pregnancies, as well as greater blood pressure reactivity to the cold pressor test. Healthy triplet pregnancies may have reduced cardiovascular function as well as a greater sympathetic contribution to cardiac control.

Cardioautonomic control in healthy singleton and twin pregnancies

In conjunction with significant cardiovascular adaptation, changes in cardioautonomic balance, specifically greater sympathetic activation and vagal withdrawal, are considered normal adaptations to healthy singleton pregnancy. Cardiovascular adaptation to twin pregnancy is more profound than that of singleton pregnancies; however, the changes in cardioautonomic control during multifetal gestation are unknown. To address this gap, beat-by-beat blood pressure (photoplethysmography) and heart rate (lead II electrocardiogram) were measured continuously in 25 twin pregnancies and 25 singleton pregnancies (matched for age, prepregnancy body mass index, and gestational age) during 10 min of rest. Data extracted from a 3- to 5-min period were used to analyze heart rate variability (HRV), blood pressure variability (BPV), cardiovagal baroreflex gain, and cardiac intervals as indicators of cardioautonomic control. Independent t tests were used to determine statistical differences between groups (α = 0.05), and the false rate discovery was determined to adjust for multiple comparisons. Resting heart rate was greater in twin compared with singleton pregnancies (91 ± 10 vs. 81 ± 10 beats/min; P = 0.001), but blood pressure was not different. Individuals with twin pregnancies had lower HRV, evidenced by lower standard deviation of R-R intervals (32 ± 11 vs. 47 ± 18 ms; P = 0.001), total power (1,035 ± 810 vs. 1,945 ± 1,570 ms²; P = 0.004), and high frequency power (224 ± 262 vs. 810 ± 806 ms²; P < 0.001) compared with singleton pregnancies. There were no differences in cardiac intervals, BPV, and cardiovagal baroreflex gain between groups. Our findings suggest that individuals with twin pregnancies have greater sympathetic and lower parasympathetic contributions to heart rate and that cardiac, but not vascular, autonomic control is impacted during twin compared with singleton pregnancy.NEW & NOTEWORTHY Individuals with healthy twin pregnancies had lower overall heart rate variability compared with those with singleton pregnancies at similar gestational ages. These results suggest a greater sympathetic and reduced parasympathetic contribution to cardiac control in twin pregnancies. Baseline heart rate was elevated, while arterial pressure and spontaneous cardiovagal baroreflex gain were not different between groups. This was result of the upward resetting of the cardiovagal baroreflex during healthy twin pregnancy, thus maintaining arterial pressure.

Assisted reproductive technology and long-term ophthalmic morbidity of the offspring

In this study, we investigate if children born following assisted reproduction technologies (ARTs) are at an increased risk for long-term ophthalmic complications. For this purpose, a population-based cohort analysis was conducted which included all deliveries between 1991 and 2014 at a single tertiary medical center. Offspring were classified relative to conception method as ART or spontaneous pregnancies. Offspring hospitalizations up to the age of 18 years involving ophthalmic morbidities were evaluated according to a predefined set of ICD-9 codes. A Kaplan-Meier survival curve was used to compare cumulative hospitalization rates in exposed (ART) and unexposed offspring (spontaneous), and a Cox proportional hazards model was used to control for potential confounders. A total of 243,682 deliveries were included in the study. In that, 1.8% of the deliveries (4364) were of mothers who underwent fertility treatments and 98.2% (239,318) were conceived spontaneously. Offspring born to mothers who underwent fertility treatments had a significantly higher hospitalization rate involving ophthalmic morbidity, as compared to spontaneously conceived offspring (1.2% vs. 1.0%, p = 0.04). The Kaplan-Meier survival curve pointed to a significantly higher cumulative incidence of ophthalmic morbidity following ART (log rank p = 0.02). Cox proportional hazards model was adjusted for maternal age, preterm delivery, maternal hypertensive disorders, diabetes, and mode of delivery which demonstrated ART as an independent risk factor for long-term pediatric ophthalmic morbidity (adjusted hazard ratio = 1.37, CI 1.04-1.80, p-value = 0.02). We concluded that ART is an independent risk factor for long-term ophthalmic morbidity of the offspring.

Impact of mode of delivery on perinatal outcome in moderately and late preterm twin birth

OBJECTIVE

To examine the impact of the mode of delivery on neonatal and maternal outcomes in moderately and late preterm twin birth.

METHODS

This single-center cohort study included 275 live diamniotic moderately and late preterm twin deliveries at 32⁺⁰ -36⁺⁶  weeks of gestation. These twin deliveries were divided into two groups according to the planned mode of delivery: trial of labor (TOL) (N=199, 72.4%) and planned cesarean section (CS) (N=76, 27.6%). The primary outcome was neonatal morbidity. Maternal outcome and the effects of gestational age and chorionicity on neonatal outcome were also studied.

RESULTS

Of the women in the TOL group, 170 (85.4%) delivered vaginally. Both for the first and second twin, and for dichorionic or monochorionic deliveries, there were no differences between the TOL and CS groups in composite neonatal morbidity or in other neonatal outcomes. No significant differences were found between the TOL and CS groups when the moderately and late preterm gestational age cohorts were studied separately. Mothers in the planned CS group more often had puerperal infection and surgical complications in comparison with mothers in the TOL group.

CONCLUSION

Among 275 moderately and late preterm twin deliveries, planned mode of delivery did not affect neonatal outcome.

Believing that transferring more embryos will result in increased pregnancy rates: a flawed concept: a SWOT analysis

A belief exists that transferring multiple embryos can improve pregnancy rates. However, this concept is flawed. Multiple factors affect outcomes when transferring embryos, endometrial receptivity, and rates of aneuploidy among them. In this article, we will discuss how factors can affect outcomes at IVF that are independent of the number of embryos transferred. It is important to understand the role of accessory factors on pregnancy rates to be able to counsel patients as per the number of embryos that should be transferred. An understanding of this concept will also lead to a realistic understanding of how multiple embryo transfers may result in better cumulative pregnancy rates than a single transfer of multiple embryos. Finally, we will present a SWOT analysis diagram to help guide clinical decision-making.

Automated Measurements of Key Morphological Features of Human Embryos for IVF

A major challenge in clinical In-Vitro Fertilization (IVF) is selecting the highest quality embryo to transfer to the patient in the hopes of achieving a pregnancy. Time-lapse microscopy provides clinicians with a wealth of information for selecting embryos. However, the resulting movies of embryos are currently analyzed manually, which is time consuming and subjective. Here, we automate feature extraction of time-lapse microscopy of human embryos with a machine-learning pipeline of five convolutional neural networks (CNNs). Our pipeline consists of (1) semantic segmentation of the regions of the embryo, (2) regression predictions of fragment severity, (3) classification of the developmental stage, and object instance segmentation of (4) cells and (5) pronuclei. Our approach greatly speeds up the measurement of quantitative, biologically relevant features that may aid in embryo selection.

The Association between Glucose Levels and Adverse Pregnancy Outcomes in Nondiabetic Twin Pregnancies

Objective  The aim of this study is to determine if hyperglycemia in twin pregnancies without gestational diabetes mellitus (GDM) is associated with an increased risk of adverse pregnancy outcomes. Study Design  Retrospective cohort study of twin pregnancies in a single Maternal-Fetal Medicine practice between 2005 and 2019 who underwent two-step GDM screening at 24 to 28 weeks. We excluded women with pregestational or gestational diabetes. We examined the association between maternal glycemia and adverse pregnancy outcomes. Glycemia was defined as the 1-hour GCT in all women, and each of the four values of the 3-hour OGTT in women who failed the GCT (≥130 mg/dL). Primary outcomes were preeclampsia, cesarean delivery, and neonatal hypoglycemia in either twin. Statistical tests used included Pearson's correlation, Student's t -test, Mann-Whitney U test, Chi-square test for trend, and logistic regression. Results  A total of 847 women underwent a GCT and 246 women underwent an OGTT. Increasing maternal glucose levels had no positive association with adverse outcomes. Women with preeclampsia, cesarean delivery, and neonatal hypoglycemia did not have higher mean GCT or OGTT values than women without these outcomes. There was no increased risk of adverse outcomes with increasing quartiles of the GCT or OGTT values. Conclusion  In women with twin pregnancies without GDM, elevated maternal glucose levels are not associated with preeclampsia, cesarean delivery, or neonatal hypoglycemia. The altered physiology of twin gestations may modify the effect of maternal hyperglycemia on perinatal outcomes as compared with singleton pregnancies. Current approaches to screening for and treating GDM during pregnancy might not adequately account for these unique considerations among twins.

Why can't I exercise during pregnancy? Time to revisit medical 'absolute' and 'relative' contraindications: systematic review of evidence of harm and a call to action

BACKGROUND

Clinical guidelines recommend pregnant women without contraindication engage in regular physical activity. This is based on extensive evidence demonstrating the safety and benefits of prenatal exercise. However, certain medical conditions or contraindications warrant a reduction, modification or cessation of activity due to potential health risks.

AIM

To review and evaluate the evidence related to medical disorders which may warrant contraindication to prenatal exercise.

METHODS

Online databases were searched up to 5 April 2019. Forty-four unique studies that reported data on our Population (pregnant women with contraindication to exercise), Intervention (subjective/objective measures of acute or chronic exercise), Comparator (not essential) and Outcomes (adverse maternal or fetal outcomes) were included in the review.

KEY FINDINGS

We found that the majority of medical conditions listed as contraindications were based on expert opinion; there is minimal empirical evidence to demonstrate harm of exercise and benefit of activity restriction. We identified 11 complications (eg, gestational hypertension, twin pregnancy) previously classified as contraindications where women may in fact benefit from regular prenatal physical activity with or without modifications. However, the evidence suggests that severe cardiorespiratory disease, placental abruption, vasa previa, uncontrolled type 1 diabetes, intrauterine growth restriction, active preterm labour, severe pre-eclampsia and cervical insufficiency are associated with strong potential for maternal/fetal harm and warrant classification as absolute contraindications.

CONCLUSION

Based on empirical evidence, we provide a call to re-evaluate clinical guidelines related to medical disorders that have previously been considered contraindications to prenatal exercise. Removing barriers to physical activity during pregnancy for women with certain medical conditions may in fact be beneficial for maternal-fetal health outcomes.

Pregnancy outcomes of dichorionic triamniotic triplet pregnancies after in vitro fertilization-embryo transfer: multifoetal pregnancy reduction versus expectant management

Background

Trichorionic triplet pregnancy reduction to twin pregnancy is associated with a lower risk of preterm delivery but not with a lower risk of miscarriage. However, data on dichorionic triamniotic (DCTA) triplet pregnancy outcomes are lacking. This study aimed to compare the pregnancy outcomes of DCTA triplets conceived via in vitro fertilization-embryo transfer (IVF-ET) managed expectantly or reduced to a monochorionic (MC) singleton or monochorionic diamniotic (MCDA) twins at 11–13^+ 6 gestational weeks.

Methods

Two hundred ninety-eight patients with DCTA triplets conceived via IVF-ET between 2012 and 2016 were retrospectively analysed. DCTA triplets with three live foetuses were reduced to a MC singleton (group A) or MCDA twins (group B) or underwent expectant management (group C). Each multifoetal pregnancy reduction (MFPR) was performed at 11–13^+ 6 gestational weeks. Pregnancy outcomes in the 3 groups were compared.

Results

Eighty-four DCTA pregnancies were reduced to MC singleton pregnancies, 149 were reduced to MCDA pregnancies, and 65 were managed expectantly.

There were no significant differences among groups A, B, and C in miscarriage rate (8.3 vs. 7.4 vs. 10.8%, respectively) and live birth rate (90.5 vs. 85.2 vs. 83.1%, respectively) (P > 0.05).

Group A had significantly lower rates of preterm birth (8.3 vs. 84.6%; odds ratio (OR) 0.017, 95% confidence interval (CI) 0.006–0.046) and low birth weight (LBW; 9.2 vs. 93.2%; OR 0.007, 95% CI 0.003–0.020) than group C (P < 0.001).

Group B had significantly lower preterm birth (47.0 vs. 84.6%; OR 0.161, 95% CI 0.076–0.340) and LBW rates (58.7 vs. 93.2%; OR 0.103, 95% CI 0.053–0.200) than group C (P < 0.001).

Group A had significantly lower preterm birth (8.3 vs. 47.0%; OR 0.103, 95% CI 0.044–0.237; P < 0.001), LBW (9.2 vs. 58.7%; OR 0.071, 95% CI 0.032–0.162; P < 0.001) and perinatal death rates (1.3 vs. 9.1%; OR 0.132, 95% CI 0.018–0.991; P = 0.021) than group B.

Conclusion

The MFPR of DCTA triplets to singleton or MCDA pregnancies was associated with better pregnancy outcomes compared to expectant management. DCTA triplets reduced to singleton pregnancies had better perinatal outcomes than DCTA triplets reduced to MCDA pregnancies.

Absence of correlation between follicular fluid volume and follicular granulocyte colony-stimulating factor, a predictor of embryo implantation and successful delivery

Follicular granulocyte colony-stimulating factor (G-CSF) is a documented marker of embryo implantation potential. The primary objective was to determine whether follicular G-CSF levels correlate with follicular fluid volume. The secondary objectives were to assess whether follicular G-CSF is associated with oocyte maturity at the time of harvest and with delivery rate after fresh or frozen embryo transfer. Thirty-two patients undergoing intracytoplasmic sperm injection (ICSI) cycles were recruited (Centre de Procréation Médicalement Assistée (CPMA), University of Liège, Belgium). A total of 211 follicular fluid (FF) samples were individually collected at the time of oocyte harvest. FF volume was recorded, and G-CSF concentration was assessed by ELISA. The embryos were individually cultured in vitro. Their implantation and live birth rates were recorded after fresh and frozen embryo transfers. The follicular fluid volume did not correlate with the follicular G-CSF concentration. There were no differences in follicular G-CSF levels between mature and immature oocytes. The probability of successful implantation and delivery was increased for embryos with FF containing a high G-CSF concentration. There was a trend toward lower follicular G-CSF levels in cases of miscarriage. Therefore, follicular fluid volume cannot be a substitute for follicular G-CSF as a marker of embryo implantation ability.

Clinical performance of a specific granulocyte colony stimulating factor ELISA to determine its concentration in follicular fluid as a predictor of implantation success during in vitro fertilization

This study aimed to demonstrate the clinical performance of an ultra-sensitive follicular fluid (FF) granulocyte colony stimulating factor (G-CSF) immunoassay to confirm previous work, indicating a correlation between FF G-CSF concentration and live birth potential of the corresponding embryo after in vitro fertilization. This study was a noninterventional, prospective, diagnostic clinical multicentric study conducted between August 2012 and January 2014 with 396 single embryo transfers (SETs) from 278 subjects. During oocyte retrieval, FF was individually collected. Embryo morphology and implantation success were evaluated. The implantation success rate in the high G-CSF group (32.3%) was higher than the overall rate (27.5%). Similarly, for embryos with optimal morphology, implantation success rates were highest among those in the high G-CSF concentration category (34.5%) compared with low (19.6%) and intermediate (29.8%) G-CSF concentration categories. Significant differences in mean G-CSF concentrations were observed between the study sites. To minimize bias, analyses were repeated using data from the center with the largest number of SETs. In alignment with the overall analysis, this center demonstrated a 43% greater probability of implantation for optimal embryos with high G-CSF compared to the general implantation rate among optimal embryos and a 327% increase compared with the implantation rate of optimal embryos with low G-CSF.

Clinical Experience on Hearing Screening in Twins and Triplets: A Retrospective Study

Twin or multiple pregnancies often have neonatal complications. Common complications include low birth weight, respiratory distress, neonatal intensive care unit (NICU) admission (>5 days) and low APGAR score especially on second twin. (1) To compare referral rates of newborn hearing screening in twins and triplets between risk and non-risk babies for hearing loss, (2) to determine the effects of birth order on referral rates in twins and triplets. A retrospective study was carried out from the case records of the neonates enrolled in the referral based NICU hearing screening program during April 2013 to December 2014 at Institute of Obstetrics and Gynecology, Chennai. 1405 neonates (723 males and 682 females) in the age range of 3-28 days were screened during this period among which 76 were twins (38 pairs) and 9 were triplets (3 sets). We classified them further into non risk and risk babies among twins according to the Joint Committee for Infant Hearing (JCIH) recommendations. A dual step hearing screening protocol was used to screen the neonates. They were initially tested with distortion product otoacoustic emission (DPOAE) then with automated auditory brainstem response (AABR) before discharged from the hospital. Out of 76 (100%) twin babies 43 (56.58%) babies had one or more risk factors for hearing loss. Most common risk factors were low birth weight, premature birth, mechanical ventilation >5 days, hyperbilirubinemia, infections, ototoxic medications and family history of hearing loss. Each risk factor was observed in equal proportion in 1st born and 2nd born twins. 12 (15.76%) risk babies and 11 (14.47%) non risk babies failed in DPOAE testing. Out of 9 triplets babies (3 set) 3 babies had risk factors for hearing loss. One baby in 2nd born babies group failed AABR screening. Referral rates were slightly higher in 2nd born twins when compared to 1st born twins in DPOAE testing. Chi square test did not reveal any significant association between referral rates with risk factors and birth order (p > 0.05). The referral rates in twins are higher than the total population screened. There is some influence of birth order on the referral rates in twins. It needs to be further investigated on larger population.

Impact of ethnicity on adverse perinatal outcome in women with chronic hypertension: a cohort study

OBJECTIVE

To assess the impact of maternal ethnicity on the risk of adverse perinatal outcome in pregnant women with chronic hypertension.

METHODS

Demographic and delivery data were collated of women with chronic hypertension and singleton pregnancy who delivered at one of three UK obstetric units between 2000 and 2014. Multivariable logistic regression models were used to calculate risk ratios (RR), according to ethnic group, for adverse perinatal outcome, adjusted for other maternal characteristics including age, parity, body mass index, smoking status, deprivation index and year of delivery. The impact of maternal ethnicity on birth-weight centile calculation was investigated by comparing the birth-weight centile chart customized for ethnicity (Gestation Related Optimal Weight; GROW) with a birth-weight centile calculator that does not adjust for that factor (INTERGROWTH-21^st ).

RESULTS

The study cohort included 4481 pregnancies (4045 women) with chronic hypertension. Women of white ethnicity accounted for 47% (n = 2122) of the cohort and 36% (n = 1601) were of black, 8.5% (n = 379) of Asian and 8.5% (n = 379) of other ethnicity. The overall incidence of stillbirth was 1.6%, that of preterm birth < 37 weeks was 16% and that of fetal growth restriction (birth weight < 3^rd centile) was 11%. Black women, compared with white women, had the highest risk for all adverse perinatal outcomes, with stillbirth occurring in 3.1% vs 0.6% of pregnancies (adjusted RR (aRR), 5.56 (95% CI, 2.79-11.09)), preterm birth < 37 weeks in 21% vs 11% (aRR, 1.70 (95% CI, 1.43-2.01)) and birth weight < 3^rd centile in 15% vs 7.4% (aRR, 2.07 (95% CI, 1.71-2.51)). Asian women, compared with white women, were also at increased risk of adverse perinatal outcome, with stillbirth occurring in 1.6% vs 0.6% (aRR, 3.03 (95% CI, 1.11-8.28)), preterm birth < 37 weeks in 20% vs 11% (aRR, 1.82 (95% CI, 1.41-2.35)) and birth weight < 3^rd centile in 12% vs 7.4% (aRR, 1.69 (95% CI, 1.24-2.30)). The sensitivity and specificity for prediction of infants requiring neonatal unit admission were 40% and 93%, respectively, for those with birth weight < 3^rd centile according to GROW charts, compared with 16% and 96%, respectively, for those with birth weight < 3^rd centile according to INTERGROWTH-21^st charts.

CONCLUSIONS

Black ethnicity, compared with white, is associated with the greatest risk of adverse perinatal outcome in women with chronic hypertension, even after adjusting for other maternal characteristics. Women of Asian ethnicity are also at increased risk, but to a lesser extent. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Evaluation of oxidative stress and δ-aminolevulinate dehydratase activity in twin pregnancies

Purpose: To assess and understand the maternal oxidative stress in twin pregnancies, currently not studied, through ascertain indicators of oxidative damage in maternal blood in response of two fetuses, as well as the relation of placenta with or without the increase of oxidative stress in these gestations.Materials and methods: The activity of delta-aminolevulinate dehydratase (δ-ALA-D) was analyzed as an indirect marker of oxidative stress, as well as the quantification of thiobarbituric acid reactive substances (TBARS), protein thiol groups (P-SH) and nonprotein thiol groups (NP-SH), vitamin C (VIT C) and catalase activity (CAT) in maternal blood samples from twin (n = 30) and single (n = 30) pregnancies. This study was approved by the Human Ethics Committee UFSM (register by the number 49823015.4.0000.5346).Results: TBARS was significantly higher in twin pregnancies, while thiol groups, VIT C and CAT were decreased, asides from the reduced activity of δ-ALA-D in comparison to single fetus gestations.Conclusions: The study established an oxidative stress increased and an antioxidant ability decreased in twin pregnancies, suggesting a possible relation between the levels of oxidants and antioxidants with the complications in those gestations.

Ultrasound study of fetal movements in singleton and twin pregnancies at 12-19 weeks

Objective To evaluate fetal behavioral differences between singleton and twin fetuses before 20 weeks of gestation using four-dimensional (4D) ultrasound. Methods 4D ultrasound was used to examine fetal movements in 58 singleton and 48 twin normal fetuses at 12-19 weeks. The frequencies of eight fetal movements were assessed through 15-min recordings. The fetuses were divided into two gestational age groups (12-13 and 14-19 weeks) to evaluate the changes with advancing gestation in twin versus singleton fetuses. Results Arm and general movements were the most frequent movements in singleton fetuses, whereas only general movement was significantly more frequent than the other seven fetal movements in twin fetuses at 12-13 weeks. At 14-19 weeks, frequencies of arm and leg movements were significantly higher than those of the other six movements in singleton fetuses, while only arm movement was significantly more frequent than the other fetal movements in twin fetuses. Comparisons of fetal movements between singleton and twin fetuses revealed that only arm movement showed a significant difference at 12-13 weeks, while the frequencies of all movements in singleton fetuses were significantly higher than those in twin fetuses at 14-19 weeks. Conclusion Our results suggest that the limitation of available space and crowding of twin fetuses with advancing gestation may have a marked impact on twin fetal movements compared with singleton fetuses, even in the first half of pregnancy. Further studies are needed to assess whether decreased fetal movements in twin pregnancy can affect fetal and neonatal development and maturation before and after birth.

Risk factors for perinatal mortality in Murmansk County, Russia: a registry-based study

Background: Factors contributing to perinatal mortality (PM) in Northwest Russia remain unclear. This study investigated possible associations between selected maternal and fetal characteristics and PM based on data from the population-based Murmansk County Birth Registry.

Objective: This study investigated possible associations between selected maternal and fetal characteristics and PM based on data from the population-based Murmansk County Birth Registry.

Methods: The study population consisted of all live- and stillbirths registered in the Murmansk County Birth Registry during 2006–2011 (n = 52,806). We excluded multiple births, births prior to 22 and after 45 completed weeks of gestation, infants with congenital malformations, and births with missing information regarding gestational age (a total of n = 3,666) and/or the studied characteristics (n = 2,356). Possible associations between maternal socio-demographic and lifestyle characteristics, maternal pre-pregnancy characteristics, pregnancy characteristics, and PM were studied by multivariable logistic regression. Crude and adjusted odds ratios with 95% confidence intervals were calculated.

Results: Of the 49,140 births eligible for prevalence analysis, 338 were identified as perinatal deaths (6.9 per 1,000 births). After adjustment for other factors, maternal low education level, prior preterm delivery, spontaneous or induced abortions, antepartum hemorrhage, antenatally detected or suspected fetal growth retardation, and alcohol abuse during pregnancy all significantly increased the risk of PM. We observed a higher risk of PM in unmarried women, as well as overweight or obese mothers. Maternal underweight reduced the risk of PM.

Conclusions: Our results suggest that both social and medical factors are important correlates of perinatal mortality in Northwest Russia.

Incidence and risk factors for gestational diabetes mellitus in twin versus singleton pregnancies

OBJECTIVE

To compare the incidence and risk factors for gestational diabetes mellitus (GDM) between women with twin and singleton pregnancies.

METHODS

Retrospective study of all women who had a twin or singleton birth in Ontario (2012-2016). Risk ratios (RR) and 95% CIs for GDM (stratified by type of treatment) were adjusted for relevant confounding variables. Multivariable Poisson regression analysis was used to identify risk factors for GDM in twin and singleton gestations.

RESULTS

Of 270,843 women who met inclusion criteria, 266,942 (98.6%) and 3901 (1.4%) had a singleton and a twin pregnancy, respectively. Women with twins had a significantly higher risk for overall GDM (aRR = 1.13, 95% CI 1.01-1.28) and diet-treated GDM (aRR = 1.20, 95% CI 1.01-1.42) while the association with insulin-treated GDM was not significant (aRR = 1.07, 95% CI 0.89-1.28). Maternal age ≥ 35 years, non-Caucasian ethnicity and BMI > 30 kg/m² were independent risk factors for GDM among women with twins and singletons, and the magnitude of the association of these factors with GDM was similar.

CONCLUSIONS

Women with twins are at increased risk of GDM, mainly due to a higher rate of diet-treated GDM. Despite higher baseline risk of GDM in women with twins, the effect of known risk factors for GDM is similar to that observed in singletons.

The biological basis and prevention of preterm birth

The time of birth is a critical determinant of perinatal and long-term outcomes. Preterm birth is still the first cause of infant mortality and morbidity; unfortunately, rates of preterm birth remain high in both high- and low-resource countries, ranging from 5% to 18%. Preterm parturition is a syndrome, which can be induced by various factors such as infection, cervical pathology, uterine overdistension, progesterone deficiency, vascular alterations (utero-placental ischemia, decidual hemorrhage), maternal and fetal stress, allograft reaction, allergic phenomena, and probably other several unknown factors. These various etiologies can lead to the pathological activation of a common pathway of decidua/fetal membranes, which causes uterine contractility, cervical ripening, and rupture of membranes. Moreover, the mechanisms responsible for these processes have been identified, which involve receptors, chemokines, and inflammatory cytokines. It is very important to understand the cellular and biochemical pathways responsible for preterm labor to identify, treat, and prevent negative outcome in a timely manner. Clinicians and researchers play a key role in improving biochemical knowledge on preterm delivery, identifying risk factors, and shaping interventions that can address this complex syndrome.