Modes of delivery of first and second twins as a function of their presentation. Study of 614 consecutive patients from 1992 to 2000

Induction of labor in twin pregnancies - A retrospective cohort study

OBJECTIVE

To investigate outcomes in spontaneous and induced twin deliveries. Secondary aims were to study impact of delivery interval and breech presentation of the first twin.

METHODS

This retrospective cohort study comprised 354 twin deliveries at a tertiary Norwegian hospital. Spontaneous labor onset and induction of labor were compared in women with planned vaginal delivery and gestational age ≥ 34 weeks. The main outcome was intrapartum cesarean section. Secondary outcomes were umbilical arterial pH and five-minute Apgar scores.

RESULTS

Among the induced labors, 63/229 (27.5%) women underwent intrapartum cesarean section, compared to 45/125 (36%) in spontaneous labors (P = 0.10). Odds ratio for intrapartum cesarean section in induced labors was 0.65 (95% CI 0.40-1.04) after adjusting for maternal age and parity. Median umbilical arterial pH was significantly lower in the second twins in both spontaneous and induced labors, 7.28 (6.94-7.43) vs. 7.32 (7.16-7.42), and 7.27 (6.90-7.48) vs. 7.29 (7.08-7.45), respectively. pH < 7.00 rarely occurred. Second twins born after a delivery interval > 30 min had a significantly higher frequency of pH < 7.10 than those with a shorter interval, P < 0.01. No significant difference was found in frequency of pH < 7.10 between breech-presenting and cephalic-presenting first twins (P = 0.65). One unexpected intrapartum fetal death occurred after labor induction.

CONCLUSION

Our results support spontaneous onset and induction of labor as safe. Intrapartum cesarean section rates did not differ significantly between spontaneous and induced labors. Delivery interval > 30 min was associated with a lower pH in the second twin.

[Delivery of twin pregnancy and materno-fetal prognosis in a level 3 Tunisian University Center: a retrospective study about 399 cases]

En dépit des progrès obstétricaux et pédiatriques, les grossesses gémellaires représentent une situation à haut risque aussi bien pour le déroulement de la grossesse que pour l´accouchement et reste encore une situation angoissante pour l´équipe obstétricale. Le but de cette étude était de décrire la pratique des accouchements des grossesses gémellaires au service de gynécologie obstétrique de Sousse, de décrire le pronostic maternel et fœtal et d´analyser les facteurs pouvant l´influencer. Nous avons réalisé une étude descriptive, rétrospective portant sur les accouchements des grossesses gémellaires sur une période de deux ans. Ont été incluses dans l´étude les grossesses gémellaires ayant atteint au moins 28 semaines d´aménorrhée (SA) et les femmes ayants une grossesse gémellaire compliquée d'une mort fœtale in utéro. Ont été exclues les femmes ayant une grossesse gémellaire et ayant accouchés avant 28 SA. Les grossesses bi-choriales bi-amniotiques représentaient 67% des cas, contre seulement 11,5% de grossesses mono-choriales bi-amniotiques et 3% de grossesses mono-choriale mono-amniotique. Nous avons recensé 52 césariennes programmées. Le travail a été spontané dans 304 cas. Il a été déclenché dans 43 cas. Au total 178 parturientes ont accouché par voie basse (44,6%), contre 215 par voie haute (53,9%). Le taux de césarienne pour le deuxième jumeau était de 1,5%. Quand l'accouchement était par voie basse, 19 cas de complications ont été observés (10,7%). Nous avons analysé le score d'Apgar du premier jumeau et du deuxième jumeau en fonction du mode d'accouchement. Il n'y a pas eu de différence statistiquement significative du score d'Apgar entre les deux voies d'accouchement. La morbi-mortalité périnatale est plus importante pour le deuxième jumeau que pour le premier jumeau. La morbidité maternelle en cas d´accouchement par voie basse était supérieur à la morbidité en cas d´accouchement par césarienne. Il n´y a pas de différences significatives dans le score d´Apgar selon que les enfants sont nés par voie basse ou par césarienne.

Pre- and Perinatal Characteristics Associated with Apgar Scores in a Review and in a New Study of Dutch Twins

A literature review was carried out to identify pre and perinatal characteristics associated with variation in Apgar scores in population-based studies. The parameters identified in the literature search were included in the classical twin design study to estimate effects of pre and perinatal factors shared and nonshared by twins and to test for a contribution of genetic factors in 1- and 5-min Apgar scores in a large sample of Dutch monozygotic (MZ) and dizygotic (DZ) twins. The sample included MZ and DZ twins (N = 5181 pairs) recruited by the Netherlands Twin Register shortly after birth, with data on prenatal characteristics and Apgar scores at first and/or fifth minutes. The ordinal regression and structural equation modeling were used to analyze the effects of characteristics identified in the literature review and to estimate genetic and nongenetic variance components. The literature review identified 63 papers. Consistent with the review, we observed statistically significant effects of birth order, zygosity and gestational age (GA) for 1- and 5-min Apgar scores of both twins. Apgar scores are higher in first-born versus second-born twins and DZ first-born versus MZ first-born twins. Birth weight had an effect on the 5-min Apgar of the first born. Fetal presentation and mode of delivery had different effects on Apgar scores of first- and second-born twins. Parental characteristics and chorionicity did not have significant main effects on Apgar scores. The MZ twins' Apgar correlations equaled the DZ Apgar correlations. Our analyses suggest that individual differences in 1- and 5-min Apgar scores are attributable to shared and nonshared pre and perinatal factors, but not to genotypic factors of the newborns. The main predictors of Apgar scores are birth order, zygosity, GA, birth weight, mode of delivery and fetal presentation.

Mode of delivery of twin pregnancies with the first twin in breech position after the introduction of a policy of planned caesarean delivery for nulliparous women

INTRODUCTION

To evaluate the impact of the mode of delivery of twin pregnancies with the first twin in breech position for all parities combined after introduction of a policy of planned caesarean section in 38 weeks' gestation in nulliparas.

MATERIAL AND METHODS

A retrospective study of the mode of delivery of twin pregnancies with the first twin in breech position was conducted from January 2007 to December 2015 after the implementation of a planned caesarean section in 38 weeks' gestation in nulliparas. Maternal and neonatal outcomes were compared according to the decision of attempted vaginal or planned caesarean delivery.

RESULTS

Among the 134 women included, an attempted vaginal delivery was decided for 30.6% women (n = 41), with 95% (n = 39) who delivered vaginally and 5% (n = 2) by caesarean section during labour. Among the 69.4% women (n = 93) with a planned caesarean section, 64.5% (n = 60) and 11.8% (n = 11) delivered by caesarean before labour and during labour, respectively, and 23.7% (n = 22) delivered vaginally. The overall vaginal delivery rate was 45.5%, and the overall rate of caesarean section was 54.5% for all parities combined. In nulliparous women, the rate of caesarean section during labour was 33%. There were no significant differences in maternal mortality or morbidity between the two groups.

CONCLUSION

A selective policy of attempted vaginal delivery based on parity for twin pregnancies with the first twin in breech position can lead to a reduction in the overall rate of caesarean section in this population.

Mode of birth in twins: data and reflections

Our primary objective was to compare neonatal and maternal outcomes in women with twin pregnancies, beyond 32 weeks, having a planned vaginal birth or a planned caesarean section (CS). This was a retrospective cohort study from a single tertiary centre over nine years. 534 sets of twins ≥32 + 0 weeks of gestation were included. 401 sets were planned vaginally and 133 sets were planned by CS. We compared a composite adverse perinatal outcome (perinatal mortality or serious neonatal morbidity; five minute APGAR score ≤4, neurological abnormality and need for intubation) and a composite maternal adverse outcome (major haemorrhage, trauma or infection) between the groups. There were no significant differences. Given the similarity of these results with several other larger studies of twin birth, we sought to look at reasons why there is still a rising rate of CS for twin births. We further make suggestions for keeping this rate to a sensible minimum. Impact statement What is already known on this subject? The largest randomised controlled study comparing planned vaginal birth with planned CSs for lower risk twins between 32 and 39 weeks of gestation, showed no added safety from planned CS. However, in most of the Western countries this conclusion has failed to increase the number of planned vaginal births for lower risk twins. What do the results of this study add? This observational study from a single tertiary centre provides external validation of the twin trial results in a practical day-to-day setting. It also provides insights as to how planned vaginal birth can be developed and maintained, with a key focus on safety and maternal participation in decision making. It does focus on consent and providing accurate data. What are the implications of these findings for clinical practice and/or further research? There are good grounds to encourage vaginal birth for low-risk twin pregnancies. The trend of rising caesarean rates in low-risk twin pregnancies worldwide will erode important skills for the conduct of vaginal births without any clear benefit for mothers or babies. The current situation demands careful thought about implementing innovative training opportunities for younger obstetricians. Finally, we need intelligent responses to many non-evidence-based factors which can drive clinical practice.

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.

Racial disparities in outcomes of twin pregnancies: elective cesarean or trial of labor?

OBJECTIVE

The objective of the study was to determine the relationships between maternal race and obstetric outcomes in twin gestations by planned mode of delivery.

STUDY DESIGN

We performed a secondary analysis of the Consortium on Safe Labor data. Patients with twin gestations in vertex-vertex presentation greater than 32 weeks' gestational age were grouped according to race. Demographic information and neonatal and maternal outcomes were analyzed according to planned mode of delivery: elective cesarean or trial of labor (with subsequent vaginal delivery, unplanned cesarean, or combined delivery). The primary outcome was unplanned cesarean. Secondary outcomes included maternal and neonatal outcomes.

RESULTS

One thousand nine vertex-vertex twin pregnancies were identified. There were no significant differences across ethnicities in the rate of unplanned cesarean delivery, which occurred in 233 of patients undergoing trial of labor (27%). Elective cesarean occurred in 151 patients (15%). African American women were less likely to have an elective cesarean compared with whites (odds ratio, 0.5; 95% confidence interval, 0.3-0.8), and Asian women were more likely to have an elective cesarean compared with whites (odds ratio, 2.0; 95% confidence interval, 1.2-3.4. Combined delivery occurred in 67 patients (8%) and did not differ among the groups. Subgroup analysis did not reveal any significant differences in neonatal outcomes. Adverse maternal outcomes were rare across ethnicities.

CONCLUSION

Unplanned cesarean delivery rates are similar in twin pregnancies, regardless of race. Maternal and neonatal outcomes in twin gestations are similar across ethnicities, regardless of mode of delivery.

[Active management of the second twin for vaginal delivery: ruptured versus intact membranes. Apropos a series of 182 patients]

AIM

The vaginal management of the second twin (T2) differs throughout our country. In 2009, the French National College of Gynecologists and Obstetricians released practice guidelines, with low-level evidence, encouraging active management of the second twin, using maneuvers with intact membrane.

PATIENTS AND METHODS

In our level III labour ward, these maneuvers are systematically performed when the second twin is in a breech or transverse presentation and after ruptured membranes in most cases. We studied 182 twin pregnancies with active management of the T2 at more than 28 weeks of gestation, from 1st January 1996 to 31st December 2010, by comparing the membrane status during delivery of T2.

RESULTS

The results did not show any significant differences between the two groups of patients concerning the neonatal or maternal results. The technique is feasible, even by residents. Our results show that total breech extraction of the second twin with ruptured membranes is feasible, which allows for reappraisal of the national recommendations.

CONCLUSION

In our practice, it is possible to actively deliver the T2 with ruptured membranes without altering maternal and fetal prognosis and thus simplifying learning for young doctors.

Mode of delivery in non-cephalic presenting twins: a systematic review

Purpose

This systematic review aims to determine if there are evidence-based recommendations for the optimal mode of delivery for non-cephalic presenting first- and/or second twins. We investigated the impact of the mode of delivery on neonatal outcome for twin deliveries with (1) the first twin (twin A) in non-cephalic presentation, (2) the second (twin B) in non-cephalic presentation and (3) both twins in non-cephalic presentation.

Methods

A computer-aided search of Medline, Embase, Cinahl and Cochrane databases was carried out and quality of the studies was assessed with the Cochrane Collaboration’s tool for assessing risk of bias and the GRADE approach.

Results

One high-quality clinical trial (60 twin pairs) and 16 moderate/low-quality observational studies (3,167 twin pairs) showed no difference in neonatal outcome between vaginal and caesarean delivery in twin A and/or B.

Conclusion

Our results do not suggest benefit of caesarean over vaginal delivery for selected twin gestations with twin A and/or twin B in non-cephalic presentation. However, no final conclusion can be drawn due to the small sample sizes and statistic limitations of the included studies. Randomized studies with sufficient power are required to make a strong recommendation.

Trends in cesarean delivery for twin births in the United States: 1995-2008

OBJECTIVE

To estimate trends and risk factors for cesarean delivery for twins in the United States.

METHODS

This was a cross-sectional study in which we calculated cesarean delivery rates for twins from 1995 to 2008 using National Center for Health Statistics data. We compared cesarean delivery rates by year and for vertex compared with breech presentation. The order of presentation for a given twin pair could not be determined from the available records and therefore analysis was based on individual discrete twin data. Multivariable logistic regression was used to estimate independent risk factors, including year of birth and maternal factors, for cesarean delivery.

RESULTS

Cesarean delivery rates for twin births increased steadily from 53.4% to 75.0% in 2008. Rates rose for the breech twin category (81.5%-92.1%) and the vertex twin category (45.1%-68.2%). The relative increase in the cesarean delivery rate for preterm and term neonates was similar. After risk adjustment, there was an average increase noted in cesarean delivery of 5% each year during the study period (risk ratio 1.05, 95% confidence interval 1.04-1.05).

CONCLUSION

Cesarean delivery rates for twin births increased dramatically from 1995 to 2008. This increase is significantly higher than that which could be explained by an increase in cesarean delivery for breech presentation of either the presenting or second twin.

[Twin delivery with the first twin in breech position. A study of 137 continuous cases]

AIM

The first twin (T1) in breech position is at risk of complications during vaginal delivery, making the choice of the appropriate delivery route highly important. Although British and American practice guidelines recommend the cesarean section, the French National College of Obstetricians and Gynecologists concluded that there was not enough data to choose one delivery route or the other. In this context, we set out to describe practices in our centre.

MATERIAL AND METHODS

Our retrospective study was conducted at a level III labor ward between January 1st, 1995 and December 31st, 2006. One hundred and thirty-seven twin pregnancies at more than 26 gestational weeks (GW), with T1 in breech and T2 in any position, were included.

RESULTS

A cesarean section was performed before labor in 60.6 % cases. Among the 54 (39.4 %) cases where a trial of labor was accepted, 29 patients (53.7 % success rate) delivered vaginally and 25 (46.3 %) had a cesarean section during labor. No statistical difference was observed between the neonatal outcomes after cesarean section as compared to vaginal birth. However, a significant relationship was found between delivery route and parity. Less than one-third of nulliparas versus two-third of patients with a history of at least one delivery, having trials of labor, ultimately gave birth vaginally. Thus, we observed a high rate of cesarean section during labor in nulliparas (68 % of the initially accepted trials of labor).

CONCLUSION

Our study is the first one that clearly shows that the success rate of the trial of labor is closely related to a history of vaginal birth. Following these results and because of more than two-third of cesarean section during labor in nulliparas, we subsequently plan an elective cesarean section at the 38th GW for nulliparas with twin pregnancies and T1 in breech position. Nevertheless, if any of these patients go in labor before the cesearean section, a careful trial of labor is offered.

Is a planned cesarean necessary in twin pregnancies?

OBJECTIVE

Evaluation of elective cesarean section for twin delivery as a standard of care.

DESIGN

Historical cohort in a national database (2 597 twin pregnancies).

SETTING

France.

SAMPLE

Twins with first child in cephalic presentation.

METHODS

Decision analysis.

MAIN OUTCOME MEASURES

All neonatal complications, i.e. death, whether intrapartum or in the delivery room or the immediate postpartum period, or neonatal transfer to intensive (or special) care, or trauma, of one or both twins.

RESULTS

When we focused on neonatal complications for either or both twins, the strategy of planned vaginal delivery was preferable; the weight of its decision tree branch was lower than that for planned cesarean (26.5 vs. 31.7). If only twin 2 was considered, vaginal delivery was also preferred (weight of vaginal delivery=27.6 vs. 32.7 for planned cesarean). As long as the morbidity and mortality of twin 1 or twin 2 or both during a cesarean for twin 2 in the case of planned vaginal delivery does not exceed 31.5%, all else being equal, vaginal delivery should be preferred to a planned cesarean for twin 1 and twin 2. The two-variable sensitivity analysis confirmed the robustness of the results.

CONCLUSIONS

The results of our study do not support a policy of planned cesarean delivery for twin pregnancies at and after 34 weeks of gestation.

LEVEL OF EVIDENCE

II.

[Modes of deliveries of twins as a function of their presentation. A study of 371 pregnancies]

OBJECTIVE

In France, global rate of caesarian section in twin pregnancies has been 50.2% in 2003. Modes of delivery according to different twin presentations remain controversial in the literature. The purpose of our study is to analyze our practice of twin deliveries in a 5-year period, with neonatal outcomes.

PATIENTS AND METHODS

Among 22,243 women having delivered in our maternity (22 weeks and over) during the study period, the study population consisted of 371 twin pregnancies, of which 305 after 33 weeks gestation.

RESULTS

Different presentations were relatively identical whatever the gestational age of pregnancies: the "cephalic-cephalic" presentation represented 60 to 70% of the total, the "cephalic-breech" presentation approximately 10% while the "breech-cephalic" or "breech-breech" presentations approximately 8% each. Mean terms of pregnancies were 35.2 ± 2.8 weeks, mean birthweight being 2243 ± 561 g. C-section rate was 53.5%. When the first twin was in cephalic presentation, C-section rate was 40% while it was almost 100% when the first twin was in breech or "other" presentations.

CONCLUSION

There were no significant differences in neonatal outcomes (mean birthweights, Apgar scores, transfers in neonatology, perinatal deaths) according to different mode of deliveries (vaginal or C-sections). Our policy of planned cesarean section may need to be revised.

Neonatal outcomes of twins according to birth order, presentation and mode of delivery: a systematic review and meta-analysis

BACKGROUND

The optimal mode of delivery for twins is undetermined.

OBJECTIVE

To review literature regarding the neonatal outcomes following twin delivery.

DATA SOURCES

Searches were conducted in PubMed, Medline, Embase, Cochrane library and reference lists.

SELECTION CRITERIA

Studies selection criteria were: both twins alive at labour, outcomes stratified for birth order, presentation, planned and actual delivery mode. Eighteen articles were included in the meta-analysis (39, 571 twin sets).

DATA COLLECTION AND ANALYSIS

The Meta-analysis of Observational Studies in Epidemiology guidelines were followed. Interstudy heterogeneity (I(2) ) was tested. A fixed model was generated whenever I(2)<25%. Pooled odds ratios (OR) with 95% CI were computed. Intergroup comparison was significant if 95% CI did not encompass 1. The first and second twins were indicated as Twin A (TA) and Twin B (TB), respectively.

MAIN RESULTS

Neonatal morbidity was lower in TA than TB (3.0 versus 4.6%; OR 0.53; 95% CI 0.39-0.70). TA experienced neonatal death less often than TB (0.3 versus 0.6%; OR 0.55; 95% CI 0.38-0.81). No differences were noted between vertex and non-vertex and attempted vaginal delivery versus planned caesarean section in either TA or TB. In TA, neonatal morbidity was lower after vaginal delivery (1.1%) than caesarean section (2.2%; OR 0.47; 95% CI 0.27-0.82). Neonatal death was not associated with actual delivery mode. In TB, morbidity following combined delivery (19.8%) was higher than after vaginal delivery (9.5%; OR 0.55; 95% CI 0.41-0.74) or caesarean section (9.8%; OR 0.47; 95% CI 0.43-0.53). When outcomes were stratified for both presentation and delivery mode, mortality rate was lower after vaginal delivery than caesarean section for both vertex and nonvertex TB. AUTHOR'S CONCLUSION: An attempt at vaginal delivery should be considered in twin pregnancies with vertex/vertex presentation.

Long-term neurologic outcome of infants born by cesarean section

Prevention of neurologic injury to the fetus through skilled and attentive care during the peripartum period is designed to identify signs of fetal distress so that appropriate obstetric interventions can occur. The impact of mode of delivery on neurologic outcome varies depending on the clinical indication for cesarean delivery and the associated maternal and fetal conditions. This review summarizes current knowledge of the impact of mode of delivery on long-term neurologic outcome.

Intervalle de naissance entre les jumeaux: une limite de temps est-elle justifiée?

OBJECTIVES

To assess the effect of the twin-to-twin delivery interval on the umbilical cord blood gas status and the neonatal outcome of the second twin following vaginal delivery.

PATIENTS AND METHODS

Retrospective study of twin deliveries at or beyond 34 weeks of gestation over a period of five years. The correlation between the twin-to-twin delivery interval, and the umbilical arterial blood gas parameters of the second twin, including pH, PO(2), PCO(2), HCO(3-) and base excess, was studied. A second analysis was performed after exclusion of non-vertex presentation, need for general anesthesia, growth restriction and weight difference between the twin>30%.

RESULTS

Two hundred and thirty-nine patients were studied. The mean twin-to-twin delivery interval was 11.3+/-6.4 minutes (between 6 and 14 minutes in 56.1% of cases). The second twin had more Apgar score<7 at 1 minute (P<0.02) and more arterial ombilical pH<7.20 (P<0.01) than the first twin. Over 15 minutes, the mean arterial pH was lower (P<0.01) and the number of arterial pH<7.20 increased (P<0.03). In contrast, the mean Apgar score and the rate of neonatal transfer did not differ significantly. There were significant negative correlations between arterial pH, base excess and bicarbonates and the twin-to-twin delivery interval (P<0.05). Similar results were found in the homogenised population. The reduction in the second twin arterial pH was expressed as pH=7.282-0.003 x time.

DISCUSSION AND CONCLUSION

Umbilical cord arterial blood gas parameters deteriorate with increasing twin-to-twin delivery interval. Our results suggest that this interval should be less than 15 minutes, but obstetrician should adapt to every clinic situation.

Trial of Vaginal Breech Delivery: Current Role

Breech presentation occurs at term in approximately 3% to 4% of singleton gestations. This presentation is associated with a variety of maternal and fetal conditions including preterm labor, abnormal amniotic fluid volume, hydrocephaly, anencephaly, mullerian anomalies, abnormal placentation, and multifetal gestation. Cesarean delivery has been associated with increased risk of subsequent accreta, placenta previa, hemorrhage, and hysterectomy. The Term Breech Trial initially suggested that planned vaginal breech delivery is associated with increased neonatal morbidity and mortality compared with planned cesarean delivery. Long-term follow-up of these vaginally delivered infants contradict the initial findings. Current debate surrounds the dilemma of whether the untoward complications of cesarean delivery are warranted given uncertain minimal increases in neonatal survival and improvement in neurologic outcome with planned cesarean.