Short communication: Vaginal delivery can be considered in monochorionic diamniotic twins

What is the success rate of trial of labor in monochorionic diamniotic twins? A systematic review and meta-analysis of observational studies

OBJECTIVE

This meta-analysis aimed to evaluate the success rate of trial of labor in monochorionic diamniotic pregnancies and the impact of delivery mode on neonatal outcomes.

DATA SOURCES

Searches were performed in MEDLINE/PubMed, Embase, Scopus, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and the International Clinical Trials Registry Platform from the inception of each database until April 2022.

STUDY ELIGIBILITY CRITERIA

Selection criteria included observational studies analyzing the delivery mode among monochorionic diamniotic gestations.

METHODS

All analyses were carried out using an intention-to-treat approach, evaluating women according to the delivery mode to which they were assigned in the original studies.

RESULTS

Seventeen studies met the eligibility criteria and were suitable for qualitative and quantitative analysis. In total, 4116 women were analyzed. This meta-analysis showed that trial of labor in monochorionic diamniotic pregnancies resulted in vaginal delivery of both twins in 75.5% of cases (95% confidence interval, 69.1-80.9). Failure to deliver the second twin vaginally occurred in 3.8% of cases (95% confidence interval, 2.5-5.7). In addition, the neonatal outcomes were comparable among women with monochorionic diamniotic pregnancy undergoing different planned delivery modes. Neonatal death occurred in 3.7 per 1000 cases in the planned cesarean delivery group and in 1.6 per 1000 cases in the planned vaginal delivery group. Perinatal death was observed in 7.5 per 1000 cases in the planned cesarean delivery group and in 5.8 per 1000 cases in the planned vaginal delivery group. Umbilical artery pH <7.00 occurred in 0 per 1000 cases in the planned cesarean delivery and 4.6 per 1000 cases in the planned vaginal delivery group. Neonatal intensive care unit stay of >72 hours had a prevalence of 59.7 per 1000 cases in the planned cesarean delivery and 42.8 per 1000 cases in the planned vaginal delivery group.

CONCLUSION

This meta-analysis showed that trial of labor in monochorionic diamniotic pregnancies is successful in most cases and relatively safe, considering that neonatal and perinatal mortality and severe morbidity were comparable between the trial of labor and planned cesarean delivery groups. Therefore, the choice of planned delivery mode in twin gestations should not be made a priori.

Mode of birth in monochorionic versus dichorionic twin pregnancies: a retrospective study from a large tertiary centre in Germany

Background

Optimal mode of birth for twins, in particular monochorionic twins, has been the subject of much debate. This retrospective study compared maternal and newborn outcomes after vaginal birth in monochorionic and dichorionic twins, utilizing a large institutional database.

Methods

Retrospective analysis focusing on 98 monochorionic-diamniotic (MC-DA) and 540 dichorionic-diamniotic (DC-DA) twin births extracted from the perinatal database of a large German hospital. Pregnancies ≥36 weeks of gestation with two viable foetuses born between 2004 and 2014 divided into planned vaginal and planned caesarean delivery were included. Descriptive analysis was performed for maternal characteristics. Odds ratios (OR) with 95% confidences intervals (CI) tested the predictive effect of vaginal birth on neonatal and maternal outcomes.

Results

51.0% MC-DA and 46.7% DC-DA twin pregnancies were planned vaginal births and 44.0% MC-DA mothers and 43.7% DC-DA mothers actually gave birth vaginally. The overall rate of caesarean section (CS) during the years under observation was 79.6% for MC-DA and 77.0% for DC-DA pregnancies. There were no significant differences in neonatal outcome between the subsamples, although acidosis was observed more often in the second DC-DA twin and Apgar scores < 7 were observed more often in MC-DA twins.

Conclusion

Vaginal birth may be recommended as an option to women with monochorionic twins as no significant differences in outcomes were found between MC-DA and DC-DA twins. However, over half of planned vaginal twin births resulted in CS.

Mode of delivery, perinatal outcome and neurodevelopment in uncomplicated monochorionic diamniotic twins: a single-center retrospective cohort study

BACKGROUND

There is no agreement on the effect of planned mode of delivery in the perinatal morbidity and neurodevelopment in uncomplicated monochorionic diamniotic as well as regarding the safest mode of delivery. In this paper we have aimed to analyze the impact of the mode of delivery in uncomplicated monochorionic diamniotic twins ≥ 32 weeks of gestation.

MATERIAL AND METHODS

This study included 72 women, followed and attended at our department, with uncomplicated monochorionic diamniotic pregnancies who had a birth between 32.0 and 37.6 weeks of gestation from January 2012 to December 2018. Outcomes were recorded in women who underwent planned vaginal delivery (induced or spontaneous onset of labor), and women who underwent a planned cesarean section for any reason that excluded vaginal delivery. Primary outcomes included: (1) A composite of any of the following: neonatal death, 5-min Apgar score < 4, respiratory distress syndrome, bronchopulmonary dysplasia, sepsis, periventricular leukomalacia, intraventricular hemorrhage, and necrotizing enterocolitis. (2) Neurodevelopmental status at 2 years of corrected age.

RESULTS

In this period, 42 women (58.3%) had a planned vaginal delivery, and 30 women (41.7%) had a planned cesarean section. In the first group, 64.3% had a vaginal delivery. The rate of successful vaginal delivery was similar regardless the onset of labor. We did not find a higher composite perinatal morbidity in the planned vaginal delivery group (planned vaginal delivery: 3.6% vs. planned cesarean section: 8.3%, aOR 1.36, 95% CI 0.24-7.81). Considering the onset of labor, it was more frequent in the spontaneous subgroup (8.3% vs. 0%). The rate of neurodevelopmental impairment was higher in the planned cesarean section group, without reaching statistical significance [10.2% vs. 4.9%, aOR 1.53 (95% CI 0.37-6.29)].

CONCLUSIONS

In uncomplicated monochorionic diamniotic twins at ≥ 32 weeks of gestation, when the first twin is in vertex presentation, our results suggest that planned vaginal delivery is safe, with a successful outcome as well as high vaginal delivery rate.

Mode of delivery in multiple pregnancies

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.

Perinatal outcome after planned vaginal delivery in monochorionic compared with dichorionic twin pregnancy

OBJECTIVE

To assess, according to chorionicity, the perinatal outcome of twin pregnancy in which vaginal delivery is planned.

METHODS

JUMODA (JUmeaux MODe d'Accouchement) was a national prospective population-based cohort study of twin pregnancies, delivered in 176 maternity units in France, from February 2014 to March 2015. In this planned secondary analysis, we assessed, according to chorionicity, the perinatal outcome of twin pregnancies, in which vaginal delivery was planned, that delivered at or after 32 weeks of gestation with the first twin in cephalic presentation. In order to select a population with well-recognized indications for planned vaginal delivery, we applied the same exclusion criteria as those in the Twin Birth Study, an international randomized trial. Monochorionic twin pregnancies with twin-to-twin transfusion syndrome or twin anemia-polycythemia sequence were defined as complicated and were excluded. The primary outcome was a composite of intrapartum mortality and neonatal morbidity and mortality. Multivariable logistic regression models were used to control for potential confounders. Subgroup analyses were conducted according to birth order (first or second twin) and gestational age at delivery (< 37 or ≥ 37 weeks of gestation).

RESULTS

Among 3873 twin pregnancies, in which vaginal delivery was planned, that delivered at ≥ 32 weeks' gestation with the first twin in cephalic presentation, meeting the inclusion criteria of the Twin Birth Study, 729 (18.8%) were uncomplicated monochorionic twin pregnancies and 3144 (81.2%) were dichorionic twin pregnancies. The rate of composite intrapartum mortality and neonatal morbidity and mortality did not differ between uncomplicated monochorionic (27/1458 (1.9%)) and dichorionic (107/6288 (1.7%)) twin pregnancies when adjusting for conception by assisted reproductive technologies (adjusted relative risk, 1.07 (95% CI, 0.66-1.75)). No significant difference in the primary outcome was found between the groups on subgroup analyses according to birth order and gestational age at delivery.

CONCLUSION

When vaginal delivery is planned, and delivery occurs at ≥ 32 weeks of gestation with the first twin in cephalic presentation, uncomplicated monochorionic twin pregnancy is not associated with a higher rate of composite intrapartum mortality and neonatal morbidity and mortality compared with dichorionic twin pregnancy. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Delivery of monochorionic twins: lessons learned from the Twin Birth Study

BACKGROUND

The current literature regarding the recommended mode of delivery of monochorionic-diamniotic twins is limited to small numbers, retrospective studies, and comparisons of outcomes of monochorionic-diamniotic twin pregnancies with those of dichorionic-diamniotic twin pregnancies instead of outcomes of trial of labor vs elective cesarean delivery of monochorionic-diamniotic twins.

OBJECTIVE

This study aimed to compare perinatal and maternal outcomes of planned cesarean delivery and planned vaginal delivery of monochorionic-diamniotic twins using the Twin Birth Study data.

STUDY DESIGN

This study is a secondary analysis of the Twin Birth Study. Women were randomized from 32 weeks and 0 days gestation to 38 weeks and 6 days gestation to planned cesarean delivery or planned vaginal delivery. Twin A in the cephalic presentation and estimated weight of each twin between 1500 and 4000 grams were the inclusion criteria. Pregnancies complicated by fetal reduction after 13 weeks of gestation, lethal fetal anomaly, or contraindication to vaginal delivery were excluded. Elective delivery was planned between 37 weeks and 5 to 7 days of gestation and 38 weeks and 6 to 7 days of gestation. Perinatal and maternal outcomes of monochorionic-diamniotic twin pregnancies were compared between those randomized for planned cesarean delivery and those randomized for planned vaginal delivery. In addition, outcomes of monochorionic-diamniotic twin pregnancies were compared with those of dichorionic-diamniotic twin pregnancies.

RESULTS

Out of the 1393 women in each arm, 346 (24.9%) women in the planned cesarean delivery arm and 324 (23.3%) women in the planned vaginal delivery arm had monochorionic-diamniotic twin pregnancies and were eligible for the first analysis. The rate of cesarean delivery was 39.2% in the planned vaginal delivery arm and was 91.3% in the planned cesarean delivery arm. There was no significant difference in gestational age at delivery between the groups (34.4±1.8 weeks vs 34.5±1.8 weeks; P=.78). No difference was found in maternal outcomes. As for perinatal outcomes, the rate of the primary adverse neonatal composite outcomes in twins A or twins B was similar in both the planned vaginal delivery and the planned cesarean delivery arms (twins A, 1.2% vs 1.2% [P=.92]; twins B, 1.2% vs 3.2% [P=.09]). Within the planned cesarean delivery arm, the rate of primary adverse neonatal composite outcome was higher in twins B than twins A (3.2% vs 1.2%; P=.03). There was no difference in the primary adverse neonatal composite outcome between twins A in the monochorionic-diamniotic group and the dichorionic-diamniotic group (1.2% vs 1.3%; P=.89) or between twins B in similar groups (2.3% vs 2.7%; P=.47).

CONCLUSION

In monochorionic-diamniotic twin pregnancy between 32 weeks and 0 to 7 days of gestation and 38 weeks and 6 to 7 days of gestation, with twin A in a cephalic presentation, planned cesarean delivery did not decrease or increase the risk of fetal or neonatal death or serious neonatal morbidity, as compared with planned vaginal delivery.

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

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

Twin births: cesarean section or vaginal delivery?

OBJECTIVE

To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery.

DESIGN

Population-based retrospective cohort.

SETTING

Fourteen obstetric departments in Denmark.

POPULATION

One thousand one hundred and seventy-five twin pregnancies with two live fetuses at 36(+0) weeks of gestation.

METHODS

Pregnancy outcomes assessed according to chorionicity and mode of delivery.

MAIN OUTCOME MEASURES

Poor outcome defined as five min Apgar score ≤ 7, umbilical artery pH < 7.10, admission to neonatal unit for more than three days or death.

RESULTS

Dichorionic (DC) twins, delivered after 36 gestational weeks, with intended vaginal delivery (n= 689) compared with DC twins with planned cesarean section (n= 371) had an increased risk of poor outcome [odds ratio (OR) 1.47, p= 0.037] after adjustment for body mass index, parity and weight discordance. There was no increased risk for poor outcome in monochorionic (MC) twins with intended vaginal delivery (n= 63) compared with planned cesarean section (n= 52; OR 0.87, 95% confidence interval 0.26-2.96). Nulliparity increased the risk of poor outcome in DC (OR 1.5, p= 0.03) and in MC twins (OR 4.01, p= 0.02), as well as birthweight discordance >300 g (DC, OR 1.50, p= 0.02; and MC, OR 6.02, p= 0.002). For DC twins, we found a significantly higher risk of poor outcome of the second-born twin compared with the first (OR 1.64, p= 0.001).

CONCLUSIONS

Dichorionic twins born after 36 weeks of gestation had a higher risk of poor outcome by intended vaginal delivery than by planned cesarean section. For MC twins, statistical differences in outcome by mode of delivery could not be seen.

Perinatal mortality and mode of delivery in monochorionic diamniotic twin pregnancies ≥ 32 weeks of gestation: a multicentre retrospective cohort study

OBJECTIVE

To study perinatal mortality rates in a cohort of 465 monochorionic (MC) twins without twin-twin transfusion syndrome (TTS) born at 32 weeks of gestation or later since reported interauterine fetal death (IUFD) rates >32 weeks of gestations in the literature vary, leading to varying recommendations on the optimal timing of delivery, and to investigate the relation between perinatal mortality and mode of delivery.

DESIGN

Multicentre retrospective cohort study.

SETTING

Ten perinatal referral centres in the Netherlands.

POPULATION

All MC twin pregnancies without TTTS delivered at ≥ 32 weeks of gestation between January 2000 and December 2005.

METHODS

The medical records of all MC twin pregnancies without TTTS delivered at the ten perinatal referral centres in the Netherlands between January 2000 and December 2005 were reviewed.

MAIN OUTCOME MEASURES

Perinatal mortality in relation to gestational age and mode of delivery at ≥ 32 weeks of gestation.

RESULTS

After 32 weeks of gestation, five out of 930 fetuses died in utero and there were six neonatal deaths (6 per 1000 infants). In women who delivered ≥ 37 weeks, perinatal mortality was 7 per 1000 infants. Trial of labour was attempted in 376 women and was successful in 77%. There were three deaths in deliveries with a trial of labour (8 per 1000 deliveries), of which two were related to mode of delivery. Infants born by caesarean section without labour had an increased risk of neonatal morbidity and respiratory distress syndrome.

CONCLUSIONS

In MC twin pregnancies the incidence of intrauterine fetal death is low ≥ 32 weeks of gestation. Therefore, planned preterm delivery before 36 weeks does not seem to be justified. The risk of intrapartum death is also low, at least in tertiary centres.