The effects of labor and delivery on maternal and neonatal outcomes in term twins: a retrospective cohort study

Maternal and fetal outcomes after planned cesarean or vaginal delivery in twin pregnancy: a comparison between 2 third level birth centers

BACKGROUND

Twin pregnancy is associated with higher risks of adverse perinatal outcomes for both the mother and the babies. Among the many challenges in the follow-up of twin pregnancies, the mode of delivery is the last but not the least decision to be made, with the main influencing factors being amnionicity and fetal presentation. The aim of the study was to compare perinatal outcomes in two European centers using different protocols for twin birth in case of non-cephalic second twin; the Italian patients being delivered mainly by cesarean section with those in Belgium being routinely offered the choice of vaginal delivery (VD).

METHODS

This was a dual center international retrospective observational study. The population included 843 women with a twin pregnancy ≥ 32 weeks (dichorionic or monochorionic diamniotic pregnancies) and a known pregnancy outcome. The population was stratified according to chorionicity. Demographic and pregnancy data were reported per pregnancy, whereas neonatal outcomes were reported per fetus. We used multiple logistic regression models to adjust for possible confounding variables and to compute the adjusted odds ratio (adjOR) for each maternal or neonatal outcome.

RESULTS

The observed rate of cesarean delivery was significantly higher in the Italian cohort: 85% for dichorionic pregnancies and 94.4% for the monochorionic vs 45.2% and 54.4% respectively in the Belgian center (p-value < 0.001). We found that Belgian cohort showed significantly higher rates of NICU admission, respiratory distress at birth and Apgar score of < 7 after 5 min. Despite these differences, the composite severe adverse outcome was similar between the two groups.

CONCLUSION

In this study, neither the presentation of the second twin nor the chorionicity affected maternal and severe neonatal outcomes, regardless of the mode of delivery in two tertiary care centers, but VD was associated to a poorer short-term neonatal outcome.

Association between Diabetes in Pregnancy and Shoulder Dystocia by Infant Birth Weight in an Era of Cesarean Delivery for Suspected Macrosomia

OBJECTIVE

 We estimated the association between diabetes and shoulder dystocia by infant birth weight subgroups (<4,000, 4,000-4,500, and >4,500 g) in an era of prophylactic cesarean delivery for suspected macrosomia.

STUDY DESIGN

 A secondary analysis from the National Institute of Child Health and Human Development U.S. Consortium for Safe Labor of deliveries at ≥24 weeks with a nonanomalous, singleton fetus with vertex presentation undergoing a trial of labor. The exposure was either pregestational or gestational diabetes compared with no diabetes. The primary outcome was shoulder dystocia and secondarily, birth trauma with a shoulder dystocia. We calculated adjusted risk ratios (aRRs) with modified Poison's regression between diabetes and shoulder dystocia and the number needed to treat (NNT) to prevent a shoulder dystocia with cesarean delivery.

RESULTS

 Among 167,589 assessed deliveries (6% with diabetes), pregnant individuals with diabetes had a higher risk of shoulder dystocia at birth weight <4,000 g (aRR: 1.95; 95% confidence interval [CI]: 1.66-2.31) and 4,000 to 4,500 g (aRR: 1.57; 95% CI: 1.24-1.99), albeit not significantly at birth weight >4,500 g (aRR: 1.26; 95% CI: 0.87-1.82) versus those without diabetes. The risk of birth trauma with shoulder dystocia was higher with diabetes (aRR: 2.29; 95% CI: 1.54-3.45). The NNT to prevent a shoulder dystocia with diabetes was 11 and 6 at ≥4,000 and >4,500 g, versus without diabetes, 17 and 8 at ≥4,000 and >4,500 g, respectively.

CONCLUSION

 Diabetes increased the risk of shoulder dystocia, even at lower birth weight thresholds than at which cesarean delivery is currently offered. Guidelines providing the option of cesarean delivery for suspected macrosomia may have decreased the risk of shoulder dystocia at higher birth weights.

KEY POINTS

· >Diabetes increased the risk of shoulder dystocia, even at lower birth weight thresholds than at which cesarean delivery is currently offered.. · Cesarean delivery for suspected macrosomia may have decreased the risk of shoulder dystocia at higher birth weights.. · These findings can inform delivery planning for providers and pregnant individuals with diabetes..

Multiple Pregnancy and the Risk of Postpartum Hemorrhage: Retrospective Analysis in a Tertiary Level Center of Care

The aim of our study was to identify characteristics associated with postpartum hemorrhage (PPH defined as blood loss >1000 mL) in twin pregnancies in order to select patients at higher risk to be treated. This retrospective study includes multiple pregnancies between 2015 and 2020. The possible association between pregnancy characteristics and the primary endpoint (occurrence of PPH) was conducted using chi-square or Fisher exact test and Wilcoxon test. Then, univariate logistic models were performed considering as outcome the PPH, and the odds ratios with 95% CI were estimated. Finally, a multivariate logistic model was implemented, including all significant covariates. Seven hundred seven twin pregnancies giving birth beyond 32 weeks were included and of those, 120 (16.97%) had a PPH. The univariate analysis showed that factors significantly associated with PPH were: Preterm delivery, episiotomy, neonatal weight, and mode of delivery. The multivariate analysis showed that the most important factors were episiotomy and neonatal weight. The results show that the performance of episiotomy and the neonatal weight are the factors that most impact the risk of PPH in twin pregnancies. The correct identification of factors associated with PPH in twins could ideally allow to modify the clinical management and positively affect the rate of complications.

Is Group B Streptococcus Colonization Associated with Maternal Peripartum Infection in an Era of Routine Prophylaxis?

OBJECTIVE

This study aimed to assess whether colonization with group B streptococcus (GBS) is associated with maternal peripartum infection in an era of routine prophylaxis.

STUDY DESIGN

This study presented a secondary analysis of women delivering ≥37 weeks who underwent a trial of labor from the U.S. Consortium on Safe Labor (CSL) study. The exposure was maternal GBS colonization and the outcome was a diagnosis of chorioamnionitis, and secondarily, analyses were restricted to deliveries not admitted in labor and measures of postpartum infection (postpartum fever, endometritis, and surgical site infection). Logistic regression with generalized estimating equations was used accounting for within-woman correlations. Models adjusted for maternal age, parity, race, prepregnancy body mass index, pregestational diabetes, insurance status, study site/region, year of delivery, number of vaginal exams from admission to delivery, and time (in hours) from admission to delivery.

RESULTS

Among 170,804 assessed women, 33,877 (19.8%) were colonized with GBS and 5,172 (3.0%) were diagnosed with chorioamnionitis. While the frequency of GBS colonization did not vary by chorioamnionitis status (3.0% in both groups), in multivariable analyses, GBS colonization was associated with slightly lower odds of chorioamnionitis (adjusted odds ratio [AOR]: 0.89; 95% confidence interval [CI]: 0.83-0.96). In secondary analyses, this association held regardless of spontaneous labor on admission; and the odds of postpartum infectious outcomes were not higher with GBS colonization.

CONCLUSION

In contrast to historical data, GBS colonization was associated with lower odds of chorioamnionitis in an era of routine GBS screening and prophylaxis.

KEY POINTS

· Data in an era prior to routine group B streptococcus (GBS) screening and prophylaxis showed that maternal GBS colonization was associated with a higher frequency of maternal peripartum infection.. · In the current study, GBS colonization was associated with lower odds of chorioamnionitis in an era of routine GBS screening and prophylaxis.. · The results highlight potential benefits of GBS screening and intrapartum antibiotic prophylaxis beyond neonatal disease prevention, including mitigating the risk of maternal infectious morbidity..

Planned Cesarean or planned vaginal delivery for twins: secondary analysis of randomized controlled trial

OBJECTIVE

To evaluate whether there is a differential benefit of planned Cesarean delivery (CD) over planned vaginal delivery (VD) in women with a twin pregnancy and the first twin in cephalic presentation, depending on prespecified baseline maternal and pregnancy characteristics, and/or gestational age (GA) at delivery.

METHODS

This was a secondary analysis of the Twin Birth Study, which included 2804 women with a twin pregnancy and the first twin (Twin A) in cephalic presentation between 32 + 0 and 38 + 6 weeks' gestation at 106 centers in 25 countries. Women were assigned randomly to either planned CD or planned VD. The main outcome measure was composite adverse perinatal outcome, defined as the occurrence of perinatal mortality or serious neonatal morbidity in at least one twin. The baseline maternal and pregnancy characteristics (markers) considered were maternal age, parity, history of CD, use of antenatal corticosteroids, estimated fetal weight (EFW) of Twin A, EFW of Twin B, > 25% difference in EFW between the twins, presentation of Twin B, chorionicity on ultrasound, method of conception, complications of pregnancy, ruptured membranes at randomization and GA at randomization. Separate logistic regression models were developed for each marker in order to model composite adverse perinatal outcome as a function of the specific marker, planned delivery mode and the interaction between these two terms. In addition, multivariable logistic regression analysis with backward variable elimination was performed separately in each arm of the trial. The association between planned mode of delivery and composite adverse perinatal outcome, according to GA at delivery, was assessed using logistic regression analysis.

RESULTS

Of the 2804 women initially randomized, 1391 were included in each study arm. None of the studied baseline markers was associated with a differential benefit of planned CD over planned VD in the rate of composite adverse perinatal outcome. GA at delivery was associated differentially with composite adverse perinatal outcome in the treatment arms (P for interaction < 0.001). Among pregnancies delivered at 32 + 0 to 36 + 6 weeks, there was a trend towards a lower rate of composite adverse perinatal outcome in those in the planned-VD group compared with those in planned-CD group (29 (2.2%) vs 48 (3.6%) cases; odds ratio (OR) 0.62 (95% CI, 0.37-1.03)). In pregnancies delivered at or after 37 + 0 weeks, planned VD was associated with a significantly higher rate of composite adverse perinatal outcome, as compared with planned CD (23 (1.5%) vs 10 (0.7%) cases; OR, 2.25 (95% CI, 1.06-4.77)).

CONCLUSION

The perinatal outcome of twin pregnancies with the first twin in cephalic presentation may differ depending on GA at delivery and planned mode of delivery. At 32-37 weeks, planned VD seems to be favorable, while, from around 37 weeks onwards, planned CD might be safer. The absolute risks of adverse perinatal outcomes at term are low and must be weighed against the increased maternal risks associated with planned CD. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Cesarean delivery rates for overall and multiple pregnancies in Japan: A descriptive study using nationwide health insurance claims data

AIM

Due to the lack of national perinatal registries, population-wide descriptive statistics on cesarean deliveries in Japan are unknown. We aim to describe cesarean deliveries for overall and multiple pregnancies using the Japan National Database of health insurance claims.

METHODS

We calculated the national and prefectural cesarean delivery rates for overall and multiple pregnancies in 2014. We described maternal morbidities (e.g., blood transfusion) and the place and type of the institutions providing prenatal and perinatal care.

RESULTS

The national cesarean delivery rates were 18.6% overall and 82.7% for women with multiple pregnancies. Prefectural cesarean delivery rates for overall and multiple pregnancies varied from 12.5% to 24.2% and from 49.2% to 100%, respectively, showing a moderate positive correlation (r = 0.59, p < 0.001). Overall, 1.4% of cesarean patients received an allogeneic blood transfusion, compared to 3.2% for those with multiple pregnancies. In addition, 65.9% of overall cesarean deliveries occurred at hospitals with ≥20 beds, whereas 94.6% of cesarean patients with multiple pregnancies delivered at hospitals. Older patients were more likely to receive their cesarean section at a different institution than their first visit within the same prefecture, but trans-prefectural movement during pregnancy covered by health insurance was most frequent among those in their early thirties: 7.0% overall and 10.7% for multiple pregnancies.

CONCLUSIONS

The overall cesarean delivery rate in Japan was optimal, but the rate was high for multiple pregnancies, with large regional differences. Data on patient movement across institutions and areas would help to improve the perinatal care system.

Association Between Maternal Obesity and Group B Streptococcus Colonization in a National U.S. Cohort

Objective: To investigate the association between maternal obesity as measured by prepregnancy body mass index (BMI) and group B streptococcus (GBS) colonization. Methods: We conducted a secondary analysis from the Consortium on Safe Labor Study (CSL) in the United States cohort study (2002-2008). Pregnant women with deliveries at ≥37 weeks of gestation who attempted labor were included (115,070 assessed deliveries). The association between maternal prepregnancy BMI, categorized as normal weight or below (<25 kg/m²), overweight (25 to <30 kg/m²), class I obesity (30 to <35 kg/m²), class II obesity (35 to <40 kg/m²), and class III obesity (≥40 kg/m²), and GBS colonization was modeled using logistic regression with generalized estimating equations. Models adjusted for maternal age, parity, race, pregestational diabetes, insurance status, study site/region, and year of delivery. Results: The overall prevalence of GBS colonization was 20.5% (23,625/115,070), which increased with rising maternal BMI, normal weight 19.3% (13,543/70,098), overweight 20.8% (5,353/25,733), class I obesity 23.0% (2,596/11,275), class II obesity 26.1% (1,270/4,850), and class III obesity 27.7% (863/3,114). In multivariable analysis, increasing maternal obesity severity was associated with higher odds of GBS colonization, namely overweight (adjusted odds ratio [AOR]: 1.09, 95% confidence interval [CI]: 1.05-1.13), class I obesity (AOR: 1.20, 95% CI: 1.15-1.26), class II obesity (AOR: 1.42, 95% CI: 1.33-1.51), and class III obesity (AOR: 1.50; 95% CI: 1.38-1.62) compared with normal weight. In secondary analyses, these associations persisted when stratified by maternal race. Conclusions: In a national U.S. sample, increasing maternal obesity severity as assessed by prepregnancy BMI was associated with a higher likelihood of maternal GBS colonization during pregnancy.

Severe maternal morbidity by mode of delivery in women with twin pregnancy and planned vaginal delivery

Planned vaginal delivery in twin pregnancies has three potential outcomes: vaginal or cesarean delivery of both twins, or cesarean for the second twin. Our objective was to assess the association between delivery mode and severe acute maternal morbidity (SAMM) in women with twin pregnancies and planned vaginal deliveries. We limited this planned secondary analysis of the JUMODA cohort, a national prospective population-based study of twin deliveries, to women with planned vaginal delivery at or after 24 weeks of gestation who gave birth to two live fetuses at hospital. The association between delivery mode and SAMM was estimated from multivariate Poisson regression models. Of 5,055 women with planned vaginal delivery, 4,007 (79.3%) delivered both twins vaginally, 134 (2.6%) had cesarean for the second twin and 914 (18.1%) cesarean for both twins. Compared to vaginal delivery of both twins, the risk of SAMM was significantly higher after cesarean for the second twin (9.0% versus 4.5%; aRR 2.22, 95% CI 1.27-3.88) and for both twins (9.4% versus 4.5%, aRR 1.56, 95% CI 1.16-2.10). In twin pregnancies with planned vaginal delivery, cesarean deliveries for the second twin and for both twins are associated with higher risks of SAMM than vaginal delivery.

Perinatal outcomes in Finnish twins: a retrospective study

BACKGROUND

To establish the changes in perinatal morbidity and mortality in twin pregnancies in Finland, a retrospective register research was conducted. Our extensive data from a 28-year study period provide important information on the outcome of twin pregnancies in Finland that has previously not been reported to this extent.

METHODS

All 23,498 twin pregnancies with 46,996 children born in Finland during 1987-2014 were included in the study. Data were gathered from the Medical Birth Register and the Hospital Discharge Register (Finnish Institute for Health and Welfare, Finland) regarding perinatal mortality (PNM) and morbidity. For statistical analysis, binomial regression analysis and crosstabs were performed. The results are expressed in means, percentages and ranges with comparison to singletons when appropriate. Odds ratios from binomial regression analysis are reported. A p-value <0.05 was considered statistically significant.

RESULTS

There were 46,363 liveborn and 633 stillborn twins in Finland during 1987-2014. Perinatal mortality decreased markedly, from 45.1 to 6.5 per 1000 for twin A and from 54.1 to 11.9 per 1000 for twin B during the study period. Yet, the PNM difference between twin A and B remained. Early neonatal mortality did not differ between twins, but has decreased in both. Asphyxia, respiratory distress syndrome, need for antibiotics and Neonatal Intensive Care Unit (NICU) stay were markedly more common in twin B.

CONCLUSIONS

In Finland, PNM and early neonatal mortality in twins decreased significantly during 1987-2014 and are nowadays very low. However, twin B still faces more complications. The outline provided may be used to further improve the monitoring and thus perinatal outcome of twins, especially twin B.

Maternal complications in twin pregnancies in Finland during 1987-2014: a retrospective study

BACKGROUND

To investigate the trends and changes in the incidence and overall outcome of twin pregnancies in Finland, a retrospective study was conducted with emphasis on maternal complications, covering a 28-year study period.

METHODS

All 23,498 twin pregnancies with 46,363 live born and 633 stillborn children in Finland during 1987-2014 were included in the study. Data were collected from the national Medical Birth Register and the Care Register on Hospital Care (Finnish Institute for Health and Welfare, Finland) regarding the parturients' characteristics and incidences of several pregnancy and childbirth complications. The incidences of twin pregnancies and maternal complications during pregnancy and childbirth are the main outcome measures of the study. The results are expressed in percentages, means, medians, ranges and standard deviations (SD), when appropriate.

RESULTS

Twins comprised 1.4% of all births in Finland in 1987-2014. Parturients' mean age has remained stable, but the share of over 35 year-old parturients is increasing. The incidences of pre-eclampsia, intrahepatic cholestasis of pregnancy, gestational diabetes and postpartum haemorrhage have risen during the study period. Almost half (44.9%) of twins were born preterm, almost half via Caesarean section (47.1%), and 27.7% of twin labours were induced.

CONCLUSIONS

Several pregnancy complications increased during the study period. Advanced maternal age among twin parturients has risen, enhancing the risks for developing complications in a pregnancy already of a high-risk category, and predisposing to preterm delivery. National and international guidelines are necessary to improve the overall outcome of twin pregnancies.

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.

Twin pregnancy and risk of postpartum hemorrhage

Objective: To identify maternal and peripartum characteristics in twin gestations that are associated with postpartum hemorrhage (PPH) in which one or more units of packed red blood cells (PRBCs) were either administered or recommended but declined (PPH + PRBC).Methods: This retrospective cohort study evaluated all women with twin gestations who delivered at greater than 23 weeks of gestational age at a single, tertiary medical center from 2011 to 2016. Patients were included if they had documentation of estimated blood loss (EBL) at delivery and complete inpatient medical records available for review. Patients with incomplete records or an intrauterine fetal demise of one or both twins were excluded. The primary outcome was PPH + PRBC. Secondary outcomes included PPH with delivery EBL ≥1500 ml, PPH with atony and uterotonic administration, PPH with maternal hemorrhagic morbidity (MHM), and PPH with severe maternal morbidity (SMM). MHM was a composite outcome defined as PPH associated with any of the following: atony requiring uterotonics, any PRBC transfusion (≥1 unit), uterine or hypogastric artery ligation, hysterectomy, compression sutures, intrauterine balloon tamponade, uterine artery embolization, and/or exploratory laparotomy. SMM was a composite outcome defined as PPH associated with any of the following: administration of ≥4 units of PRBC, administration of ≥2 units of PRBC, and ≥2 units of fresh frozen plasma (FFP), return to operating room for any major procedure (excludes dilation and curettage), any peripartum hysterectomy, uterine artery embolization, intrauterine balloon tamponade or compression suture placed and administration of ≥2 units of PRBC, and/or intensive care unit (ICU) admission for invasive monitoring/treatment. A multivariable logistic regression analysis was performed.Results: A total of 1081 women with twin gestations were included. PPH + PRBC occurred in 4.4% (n = 48), delivery EBL ≥1500 ml occurred in 3.9% (n = 42), and atony with uterotonic administration occurred in 12.1% (n = 131) of the study population. The rate of MHM and SMM were 13.9% (n = 150) and 1.9% (n = 20), respectively. Although the rate of cesarean delivery was high overall (83.2%), it was nearly universal in the PPH + PRBC group (97.9%; p < .02). PPH + PRBC occurred at a rate of 0.5% (n = 1/182) among vaginally delivered twins compared to 5.2% (n = 47/899) among those delivered by cesarean (p < .03). The final multivariable logistic regression model to predict PPH + PRBC identified six significant maternal and peripartum factors: nulliparity, either pregestational or gestational diabetes, intrapartum magnesium sulfate, admission hematocrit <30%, admission platelets <100 000/µL and administration of general anesthesia.Conclusions: A number of maternal and peripartum factors are associated with PPH in twin gestations. Optimization of maternal hematologic parameters and chronic medical conditions, and reduction in the rate of cesarean delivery in twin pregnancies may decrease the risk of postpartum hemorrhage.

Association of chorioamnionitis and its duration with adverse maternal outcomes by mode of delivery: a cohort study

OBJECTIVE

To investigate the association of chorioamnionitis and its duration with adverse maternal outcomes by mode of delivery.

DESIGN

A retrospective cohort study.

SETTING

Data from the Consortium on Safe Labor Study in the USA (2002-2008).

POPULATION

Singleton deliveries at ≥23 weeks of gestation (221 274 assessed deliveries, 62 331 by caesarean section).

METHODS

The association of chorioamnionitis, and secondarily the duration of chorioamnionitis estimated from intrapartum antibiotic use, with adverse maternal outcomes was analysed using logistic regression with generalised estimating equations, adjusting for age, parity, race, pregestational diabetes, chronic hypertension, gestational age at delivery, study site and delivery year. Analyses were stratified by vaginal versus caesarean delivery.

MAIN OUTCOME MEASURES

The composite adverse maternal outcome included: postpartum transfusion, endometritis, wound/perineal infection/separation, venous thromboembolism, hysterectomy, admission to intensive care unit and/or death.

RESULTS

Chorioamnionitis was associated with higher odds of the composite adverse maternal outcome with caesarean delivery (adjusted odds ratio 2.31; 95% CI 1.97-2.71); and the association persisted regardless of whether a woman had a trial of labour, preterm delivery or maternal group B streptococcus colonisation. The most common adverse outcomes after caesarean section were postpartum transfusion (56.0%) and wound/perineal infection or endometritis (38.6%). Chorioamnionitis was not associated with adverse maternal outcomes after vaginal delivery. The duration of chorioamnionitis as the exposure did not alter the association between chorioamnionitis and adverse maternal outcomes.

CONCLUSIONS

Chorioamnionitis, but not the estimated duration, was associated with increased odds of adverse maternal outcomes with caesarean delivery. This finding has implications for care programmes to prevent maternal morbidity after a caesarean section complicated by chorioamnionitis.

TWEETABLE ABSTRACT

Chorioamnionitis, but not its duration, increases the risk of adverse maternal outcomes with caesarean delivery.

Term twin birth - impact of mode of delivery on outcome

INTRODUCTION

The main aims of this study were to compare maternal and neonatal outcomes in term twin birth according to the planned mode of delivery and to study the effects of chorionicity and inter-twin delivery time on neonatal outcome.

MATERIAL AND METHODS

A single-center cohort study of 495 women with twin deliveries at ≥37⁺⁰ weeks of gestation. Term twin deliveries were divided into a trial of labor group (TOL, 69.3%) and a planned cesarean section (CS) group (30.7%). The primary outcomes were maternal and neonatal morbidity.

RESULTS

80.8% of women attempting TOL achieved vaginal birth. In the TOL group, mothers had less bleeding [median 500 mL (range 150-2700 mL) vs. 950 mL (range 150-3500 mL), p < 0.001) and fewer surgical complications (3.2% vs. 8.6%, p = 0.011), whereas second twins more often had five-minute Apgar scores of <7 (5.0% vs. 0%, p = 0.002) or umbilical artery pH < 7.05 (5.7% vs. 0%, p = 0.003), compared with the planned CS group. There was a slight, non-significant tendency for more NICU admissions in the TOL group, yet the need for NICU treatment was infrequent in the whole study material. Outcomes among dichorionic (DC) second twins were similar to those in the whole material, but among monochorionic (MC) second twins there were no differences between the TOL and planned CS groups. In secondary analysis, a five-minute Apgar score <7 occurred significantly more often in the DC group among second twins if the inter-twin delivery time exceeded 30 min.

CONCLUSIONS

TOL is a good option for women with twin pregnancy at term, regardless of chorionicity. Active management of labor for the second twin is important, also in DC births. Maternal outcomes were more favorable with TOL and although low Apgar scores and low umbilical blood pH may be more frequent after TOL - especially with the second twin - serious neonatal morbidity is rare and does not differ from that after planned CS.

Induction of twin pregnancy and the risk of caesarean delivery: a cohort study

Background

Complications are common in twin pregnancies and induction of labour is often indicated. Most methods for induction are used but data on risks related to induction methods are sparse. The aim of this study was to investigate the association between induction of labour and caesarean delivery in twin pregnancies, and to assess the influence of induction method.

Methods

Cohort study of twin pregnancies ≥ 34 weeks, planned for vaginal delivery, from two University Hospitals in Sweden. Data were collected from medical records during the periods 1994 (Örebro) and 2004 (Uppsala) to 2013. During the study period there were 78,180 live born births and 1,282 were twin births. Women with previous caesarean section were excluded. Induction methods were categorized into amniotomy, oxytocin and cervical ripening (intra cervical Foley catheter or prostaglandin). Adjusted odds ratios (AOR) with 95 % confidence interval (CI) for caesarean section were calculated by logistic regression and were adjusted for parity, maternal age, gestational length, complications to the pregnancy, infant birth weight and year of birth. Spontaneous labour onsets were used as the reference group. The main outcome measure was caesarean section.

Results

In 462 twin pregnancies, 220 (48 %) had induction of labour and 242 (52 %) a spontaneous labour onset. Amniotomy was performed in 149 (68 %) of these inductions, oxytocin was administered in 11 (5 %) and cervical ripening was used in 60 (27 %). The rate of caesarean sections was 21 % in induced and 12 % in spontaneous labours (p 0.01). The absolute risk of caesarean section following induction was: 15 % with amniotomy; 36 % with oxytocin and 37 % with Foley/prostaglandin. Induction of labour increased the risk of caesarean section by 90 % compared with spontaneous labour onset (AOR 1.9, 95 % CI 1.1-3.5) and, when cervical ripening was used, the risk increased more than two fold (AOR 2.5, 95 % CI 1.2-5.3).

Conclusion

Induction of labour in twin pregnancies increases the risk of caesarean section compared with spontaneous labour onset, especially if Foley catheter or prostaglandins are required. However, approximately 80 % of induced labours are delivered vaginally.

Association of prelabor cesarean delivery with reduced mortality in twins born near term

OBJECTIVE

To examine short-term and longer-term outcomes for twins born at or near term, comparing prelabor cesarean delivery with birth after a trial of labor.

METHODS

This study was conducted on a retrospective cohort of twin pregnancies delivered at 36 weeks of gestation or greater from 2000 to 2009. Pregnancies with an antenatal death, lethal anomaly, birth weight discordance 25% or more, or birth weight less than 2,000 g or more than 4,000 g were excluded. Outcomes included severe hypoxia, stillbirth and neonatal death, and hospital admissions or death during the first 5 years of life.

RESULTS

Approximately 45% of 7,099 twin pregnancies were delivered by prelabor cesarean delivery. Compared with delivery after labor, prelabor cesarean delivery was associated with significantly reduced risks of adverse neonatal and child outcomes including severe birth hypoxia (0.08% compared with 0.75%, relative risk 0.10, 95% confidence interval [CI] 0.04-0.26), neonatal death (0.00% compared with 0.15%, relative risk 0.05, 95% CI 0.00-0.82), and death up to 5 years of age (0.16% compared with 0.40%, relative risk 0.41, 95% CI 0.20-0.85). Whereas total mortality for first twins was similar after labor (0.15%) compared with prelabor cesarean delivery (0.16%), total mortality was four times more common in second twins born after labor (0.64%) compared with second twins born after prelabor cesarean delivery (0.16%).

CONCLUSION

Compared with prelabor cesarean delivery, twin pregnancies at and beyond 36 weeks of gestation delivered after labor have increased risks for birth outcomes associated with hypoxia, with second twins having significantly increased mortality up to 5 years of age. However, the absolute mortality rate for relatively uncomplicated twin pregnancies delivered at or near term is low and needs to be balanced against maternal morbidity.

LEVEL OF EVIDENCE

II.