Search

BACKGROUND Data on the association of inappropriate gestational weight gain (GWG) and adverse outcomes in twin pregnancies are limited and inconsistent. OBJECTIVES To perform a systematic review and meta-analysis on the association between GWG and adverse outcomes in twin pregnancies. SEARCH STRATEGY Ovid, Medline, EMBASE and Cochrane Central databases from 1 January 1990 until 23 September 2020. SELECTION CRITERIA Interventional and observational studies evaluating the association between GWG and adverse outcomes in twin pregnancies. DATA COLLECTION AND ANALYSIS Data were extracted by two independent reviewers. Summary odds ratios (OR) were calculated using a random-effects model in a subset of studies that analysed GWG as a categorical variable in relation to the Institute of Medicine (IOM) recommendations. The primary outcome was preterm birth. MAIN RESULTS From 277 citations, 19 studies involving 36 023 women with twin pregnancies were included in the qualitative analysis, of which 14 were included in the meta-analysis. Overall, 56.8% of women experienced inappropriate GWG: 35.4% (95% CI 30.0-41.0%) gained weight below and 21.4% (95% CI 14.2-29.5%) gained weight above IOM recommendations. Compared with GWG within IOM guidelines, GWG below IOM guidelines was associated with preterm birth before 32 weeks of gestation (OR 3.38; 95% CI 2.05-5.58), and a reduction in the risk of pre-eclampsia (OR 0.68; 95% CI 0.48-0.97). GWG above IOM guidelines was associated with an increased risk of pre-eclampsia that was consistent across all body mass index categories. CONCLUSIONS Inappropriate GWG affects over half of twin pregnancies, so is a common and potentially modifiable risk factor for preterm birth and pre-eclampsia.

Objective To determine the population-level impact of COVID-19 pandemic–related obstetric practice changes on maternal and newborn outcomes. Methods Segmented regression analysis examined changes that occurred 240 weeks pre-pandemic through the first 32 weeks of the pandemic using data from Ontario’s Better Outcomes Registry & Network. Outcomes included birth location, length of stay, labour analgesia, mode of delivery, preterm birth, and stillbirth. Immediate and gradual effects were modelled with terms representing changes in intercepts and slopes, corresponding to the start of the pandemic. Results There were 799 893 eligible pregnant individuals included in the analysis; 705 767 delivered in the pre-pandemic period and 94,126 during the pandemic wave 1 period. Significant immediate decreases were observed for hospital births (relative risk [RR] 0.99; 95% CI 0.98–0.99), length of stay (median change –3.29 h; 95% CI –3.81 to –2.77), use of nitrous oxide (RR 0.11; 95% CI 0.09–0.13) and general anesthesia (RR 0.69; 95% CI 0.58– 0.81), and trial of labour after cesarean (RR 0.89; 95% CI 0.83–0.96). Conversely, there were significant immediate increases in home births (RR 1.35; 95% CI 1.21–1.51), and use of epidural (RR 1.02; 95% CI 1.01–1.04) and regional anesthesia (RR 1.01; 95% CI 1.01–1.02). There were no significant immediate changes for any other outcomes, including preterm birth (RR 0.99; 95% CI 0.93–1.05) and stillbirth (RR 1.11; 95% CI 0.87–1.42). Conclusion Provincial health system changes implemented at the start of the pandemic resulted in immediate clinical practice changes but no significant increases in adverse outcomes.

The mode of delivery in multiple pregnancies has been subject to vigorous debates during the last few decades. Although observational and retrospective data were accumulated, it was not until the publication of the Twin Birth Study that evidence-based recommendations could emerge. However, although some of the most pressing questions were answered by the Twin Birth Study, other questions were left outside the scope of the study. The questions were of great interest and included the following topics: the impact of gestational age, the influence of chorionicity, and the generalizability of the results for women with a previous uterine scar. The current evidence supported a trial of labor in dichorionic-diamniotic or monochorionic-diamniotic twin pregnancies in which the first twin is in cephalic presentation at ≥32 weeks’ gestation. Dichorionic-diamniotic, monochorionic-diamniotic, and monochorionic-monoamniotic twins should be delivered at 37 0/7 to 38 0/7, 36 0/7 to 37 0/7, and 32 0/7 to 34 0/7 weeks’ gestation, respectively. Breech extraction done by a competent healthcare provider seemed to offer a higher chance of successful vaginal delivery of the second twin than the external cephalic version. The current data did not allow for a clear recommendation regarding the mode of delivery in very preterm birth of low birthweight twins, but most studies did not demonstrate a clear benefit of cesarean delivery vs trial of labor. Furthermore, a trial of labor seemed safe in women with a previous cesarean delivery. Cesarean delivery is likely beneficial for twin pregnancies with the first twin in breech presentation, monochorionic-monoamniotic twins, and higher-order multiple pregnancies. In all multiple pregnancies, delivery should be performed by an experienced practitioner competent in multiple pregnancy deliveries.

Maternal and neonatal outcomes of trial of labor after cesarean delivery of twins are similar to those of singleton trials of labor after cesarean delivery. However, previous studies did not stratify outcomes by second-twin presentation on admission to labor.To examine maternal and neonatal outcomes following trial of labor after cesarean delivery in twins with vertex-nonvertex presentation.A retrospective multicenter study was conducted including data on deliveries occurring between the years 2005 and 2020. We included trials of labor after a previous cesarean delivery (at ≥32A total of 236 twin trials of labor after cesarean delivery were included, of which 128 involved nonvertex second twins and 108 a second vertex twin. Uterine rupture rates were comparable between the groups (1/128 [0.9%] vs 1/108 [0.8%]; P=1.000). Successful trial of labor after cesarean delivery of both twins occurred in 76.6% of the exposed group vs 81.5% of the comparison group, whereas cesarean delivery of both twins was performed in 21.9% of the exposed group vs 17.6% of the comparison group (P=.418; odds ratio, 1.32; confidence interval, 0.7-2.5). Two cases of cesarean delivery of the second twin occurred in the exposed group and 1 in the comparison group (1.6% vs 0.9%, respectively, P=1.000). There was no difference between the groups in maternal outcomes, including rates of postpartum hemorrhage, blood transfusion, placental abruption, thromboembolic events, and maternal fever. Neonatal outcomes were also comparable between the groups, including rates of intensive care admission and low (≤7) 5-minute Apgar scores.Our data show that trial of labor after cesarean delivery of noncephalic second twins holds favorable maternal and neonatal outcomes, comparable with those of vertex-vertex trials of labor after cesarean delivery. Second-twin noncephalic presentation should not discourage parturients and caregivers from considering trial of labor after cesarean delivery if desired.