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

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.

Learning Disabilities in Reading and Writing and Type of Delivery in Twin Births

The aim of this study was to analyse the relationship between the type of delivery (vaginal or caesarean), as a risk factor, and the likelihood of having learning disabilities in reading (reading accuracy) and writing (phonetic and visual orthography), controlling for the interaction and/or confounding effect of gestational, obstetric, and neonatal variables (maternal age at delivery, gestational age, foetal presentation, Apgar 1, and newborn weight) among six-year-old children born in twin births. In this retrospective cohort study, the exposed and non-exposed cohorts consisted of children born by caesarean section and vaginal delivery, respectively. A total of 124 children born in twin births were evaluated in year one of primary education. Intelligence was measured using the K-BIT test; reading and writing variables were evaluated using the Evalúa-1 battery of tests, and clinical records were used to measure gestational, obstetric, and neonatal variables. Binary logistic regressions applied to each dependent variable indicated that caesarean delivery is a possible independent risk factor for difficulties in reading accuracy and phonetic and visual orthography. Future research using larger samples of younger children is required to analyse the relationship between obstetric and neonatal variables and the different basic indicators of reading and writing.

In which groups of pregnant women can the caesarean delivery rate likely be reduced safely in the USA? A multicentre cross-sectional study

OBJECTIVES

To identify obstetrical subgroups in which (1) the caesarean delivery (CD) rate may be reduced without compromising safety and (2) CD may be associated with better perinatal outcomes.

DESIGN

A multicentre cross-sectional study.

SETTING

19 hospitals in the USA that participated in the Consortium on Safe Labor.

PARTICIPANTS

228 562 pregnant women in 2002-2008.

MAIN OUTCOME MEASURES

Maternal and neonatal safety was measured using the individual Weighted Adverse Outcome Score.

METHODS

Women were divided into 10 subgroups according to a modified Robson classification system. Generalised estimated equation model was used to examine the relationships between mode of delivery and Weighted Adverse Outcome Score in each subgroup.

RESULTS

The overall caesarean rate was 31.2%. Repeat CD contributed 29.5% of all CD, followed by nulliparas with labour induction (15.3%) and non-cephalic presentation (14.3%). The caesarean rates in induced nulliparas with a term singleton cephalic pregnancy and women with previous CD were 31.6% and 82.0%, respectively. CD had no clinically meaningful association with perinatal outcomes in most subgroups. However, in singleton preterm breech presentation and preterm twin gestation with the first twin in non-cephalic presentation, CD was associated with substantially improved maternal and perinatal outcomes.

CONCLUSIONS

Women with repeat CD, term non-cephalic presentation, term twins or other multiple gestation and preterm births may be the potential targets for safely reducing prelabour CD rate, while nulliparas or multiparas with spontaneous or induced labour, women with repeat CD, term non-cephalic presentation, term twins or other multiple gestation and preterm births are potential targets for reducing intrapartum CD rate without compromising maternal and neonatal safety in the USA. On the other hand, CD may still be associated with better perinatal outcomes in women with singleton preterm breech presentation or preterm twins with the first twin in non-cephalic presentation.

Delivery of the second twin: influence of presentation on neonatal outcome, a case controlled study

Background

Spontaneous vaginal twin delivery after 32nd week of gestation is safe when first twin presenting cephalic. Aim of this study is to identify obstetric factors influencing the condition of second twin and to verify whether non-cephalic presentation and vaginal breech delivery of the second twin is safe.

Methods

This is a retrospective case controlled cohort study of 717 uncomplicated twin deliveries ≥32 + 0 weeks of gestation from 2005 to 2014 in two tertiary perinatal centers. Obstetric parameters were evaluated in three groups with descriptive, univariate logistic regression analysis for perinatal outcome of second twins.

Results

The three groups included twins delivered by elective cesarean section ECS (n = 277, 38.6%), by unplanned cesarean section UPC (n = 233, 32.5%) and vaginally (n = 207, 28.9%). Serious adverse fetal outcome is rare and we found no differences between the groups. Second twins after ECS had significant better umbilical artery UA pH (p < 0.001) and better Apgar compared to UPC (p = 0.002). Variables for a fetal population “at risk” for adverse neonatal outcome after vaginal delivery (UA pH < 7.20, Apgar 5´ < 9) were associated with higher gestational age (p = 0.001), longer twin-twin interval (p = 0.05) and vacuum extraction of twin A (p = 0.04). Non-cephalic presentation of second twins was not associated (UA pH < 7.20 OR 1.97, CI 95% 0.93–4.22, p = 0.07, Apgar 5´ < 9 OR 1.63, CI 95% 0.70–3.77, p = 0.25, Transfer to neonatal intermediate care unit p = 0.48). Twenty-one second twins (2,9%) were delivered by cesarean section following vaginal delivery of the first twin. Even though non-cephalic presentation was overrepresented in this subgroup, outcome variables were not significantly different compared to cephalic presentation.

Conclusions

Even though elective cesarean means reduced stress for second twins this seems not to be clinically relevant. Non-cephalic presentation of the second twin does not significantly influence the perinatal outcome of the second twin but might be a risk factor for vaginal-cesarean birth.

Early neonatal mortality in twin pregnancy: Findings from 60 low- and middle-income countries

Background

Around the world, the incidence of multiple pregnancies reaches its peak in the Central African countries and often represents an increased risk of death for women and children because of higher rates of obstetrical complications and poor management skills in those countries. We sought to assess the association between twins and early neonatal mortality compared with singleton pregnancies. We also assessed the role of skilled birth attendant and mode of delivery on early neonatal mortality in twin pregnancies.

Methods

We conducted a secondary analysis of individual level data from 60 nationally-representative Demographic and Health Surveys including 521 867 singleton and 14 312 twin births. We investigated the occurrence of deaths within the first week of life in twins compared to singletons and the effect of place and attendance at birth; also, the role of caesarean sections against vaginal births was examined, globally and after countries stratification per caesarean sections rates. A multi-level logistic regression was used accounting for homogeneity within country, and homogeneity within twin pairs.

Results

Early neonatal mortality among twins was significantly higher when compared to singleton neonates (adjusted odds ratio (aOR) 7.6; 95% confidence interval (CI) = 7.0-8.3) in these 60 countries. Early neonatal mortality was also higher among twins than singletons when adjusting for birth weight in a subgroup analysis of those countries with data on birth weight (n = 20; less than 20% of missing values) (aOR = 2.8; 95% CI = 2.2-3.5). For countries with high rates (>15%) of caesarean sections (CS), twins delivered vaginally in health facility had a statistically significant (aOR = 4.8; 95% CI = 2.4-9.4) increased risk of early neonatal mortality compared to twins delivered through caesarean sections. Home twin births without SBA was associated with increased mortality compared with delivering at home with SBA (aOR = 1.3; 95% CI = 1.0-1.8) and with vaginal birth in health facility (aOR = 1.7; 95% CI = 1.4-2.0).

Conclusions

Institutional deliveries and increased access of caesarian sections may be considered for twin pregnancies in low- and middle- income countries to decrease early adverse neonatal outcomes.

Birth management and fetal outcome in multiple gestation: analysis of 1.444 births

PURPOSE

Since the late 1990s, controversies came up concerning the mode of delivery for multiples births. The twin birth study indicated no difference in maternal and fetal outcome between planned vaginal delivery and planned caesarean section, but did not analyze the influence of maternal and fetal characteristics or the obstetric management in vaginal birth. The purpose of this study is to analyze these parameters regarding fetal outcome.

METHODS

A large-scale retrospective analysis of twin births (n = 1.444) was performed at a university medical center. The analysis included pregnancy, delivery, and maternal and fetal parameters, including pH and base excess (BE) differences between the first- and second-born twin (delta pH, delta BE).

RESULTS

Delta pH correlated significantly with the birth interval for various positions of twins in the womb (p < 0.05). The longer the birth interval, the greater the delta pH with a lower pH of the second twin. Delta BE values were significantly correlated with the birth interval for a combination of twins in cephalic and breech presentation. Furthermore, it could be shown that higher differences in birth weight between the first/second twin are associated with higher delta pH, higher delta BE values (all p < 0.05). We found significantly decreasing delta pH values in vaginal deliveries over secondary and, finally, primary caesarean sections (p < 0.001).

CONCLUSION

We conclude a vaginal delivery of twin appears safe if experienced staff monitor birth weight discrepancies, birth interval, and blood values consequently. A good outcome also for the second twin delivered spontaneously is nevertheless feasible if experienced staff is available.