Pregnancy outcomes before and after institution of a specialised twins clinic: a retrospective cohort study

Hypertensive disorders of pregnancy and neonatal outcomes in twin vs. singleton pregnancies after assisted reproductive technology

OBJECTIVE

Hypertensive disorders of pregnancy (HDP) are associated with an increased risk of adverse neonatal outcomes. Although twin pregnancies had a higher risk of developing HDP, it is not known whether HDP in twins will increase the risk of adverse neonatal outcomes. We aimed to assess whether this association differed in singleton and twin pregnancies in women who conceived with assisted reproductive technology (ART).

METHODS

We finally included 193,590 live births born via ART from the National Vital Statistics System (NVSS) for the years 2015-2019. We used Log-binomial regression to evaluate the associations between HDP and the risk of adverse neonatal outcomes in ART mothers.

RESULTS

Among 193,590 ART-treated mothers, there were 140,870 and 52,720 mothers who had singleton pregnancies and twin pregnancies, respectively. Those ART mothers with twin pregnancies had a higher rate of HDP than singleton pregnancies (20.5% vs. 11.0%). In singleton pregnancies, the risks of preterm birth [adjusted risk ratio (aRR)): 2.80, 95% CI 2.67-2.93], low birth weight (aRR: 2.80, 95% CI 2.67-2.93), small for gestational age (aRR: 1.41, 95% CI 1.34-1.49), 5 min Apgar <7 (aRR: 1.66, 95% CI 1.50-1.83) and cesarean section (aRR: 1.23, 95% CI 1.21-1.25) were significantly higher in HDP mothers than in non-HDP mothers respectively. However, in contrast to singleton pregnancies, these associations were weak or reversed in twin pregnancies, after adjusting for confounding factors.

CONCLUSION

In ART-treated women, although twin pregnancies had a higher HDP rate, the risk of adverse neonatal outcomes associated with HDP was lower than that of singletons.

Reduction in twin stillbirth following implementation of NICE guidance

OBJECTIVE

There has been an unprecedented fall in the rate of stillbirth in twin pregnancy in the UK. It is contested whether implementation of the National Institute for Health and Care Excellence (NICE) guidance on the antenatal management of uncomplicated twin pregnancies has contributed to this change. The aim of this study was to investigate whether the implementation of NICE guidance was associated with a reduction in the rate of stillbirth in twin pregnancies delivered in a large UK hospital.

METHODS

This was a retrospective cohort study including all twin pregnancies delivered at St George's Hospital, London, UK, between 2000 and 2018. Data were analyzed according to two time periods: before implementation of the NICE guidance on twins (before June 2013; pre-NICE) and after its implementation (after June 2013; post-NICE). The exclusion criteria were higher-order multiple gestations, pregnancies of unknown chorionicity, pregnancies complicated by miscarriage, those that underwent termination and those diagnosed with vanishing twin. The main outcome was stillbirth. Other outcomes included neonatal death (NND), admission to the neonatal intensive care unit (NICU) and emergency Cesarean section. We planned a priori a sensitivity analysis according to chorionicity. The chi-square test and Mann-Whitney U-test were used to compare outcomes between the study groups.

RESULTS

We included in the analysis 1666 twin pregnancies (3332 fetuses), of which 1114 pregnancies (2228 fetuses) were delivered before and 552 pregnancies (1104 fetuses) after June 2013. Of those, 1299 were dichorionic and 354 were monochorionic diamniotic. The incidence of stillbirth was significantly lower in the post-NICE than in the pre-NICE group (3.6 per 1000 births vs 13.5 per 1000 births; P = 0.008). The reduction in stillbirth rate was from 8.5 to 3.6 per 1000 births (P = 0.161) in dichorionic and from 33.6 to 3.8 per 1000 births (P = 0.011) in monochorionic diamniotic twin pregnancies. There was no significant difference in the rates of NND (P = 0.625), NICU admission (P = 0.506) or emergency Cesarean section (P = 0.820) between the two groups. The median gestational age at delivery was significantly lower in the post-NICE than in the pre-NICE group (median 36.3 vs 36.9 weeks; P < 0.001), as a consequence of a significant increase in preterm birth between 34 and 37 weeks' gestation (39.3% vs 27.0%; P = 0.002), but not before 34 weeks (P = 0.473).

CONCLUSIONS

A significant reduction of > 70% in the stillbirth rate in twin pregnancies was noted after implementation of the NICE guidance. This reduction was statistically significant in monochorionic, but not dichorionic, twin pregnancies. The improvement in twin pregnancy outcome was achieved without a concomitant increase in NND, admission to the NICU or emergency Cesarean section. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Expertise in physiological breech birth: A mixed-methods study

BACKGROUND

The safety of vaginal breech birth depends on the expertise of birth attendants, yet the meaning of "expertise" remains unclear and subjectively defined. The objective of this study was to define expertise and the roles experts may play in expanding access to this service.

METHODS

We performed an integrative analysis of two strands of data concerning expertise in physiological breech birth, including the following: survey data from a Delphi study involving 26 very experienced clinicians (mean experience = 135 breech births) and 2 service user representatives, and interviews from a grounded theory study of 14 clinicians more moderately experienced with physiological methods (5-30 upright breech births). Data were pooled and analyzed using constant comparative methods.

RESULTS

Expertise is defined by its ongoing function, the generation of comparatively good outcomes, and confidence and competence among colleagues. Although clinical experience is important, expertise is developed and expressed in social clinical roles, which expand as experience grows: clinician, mentor, specialist, and expert. To develop expertise within a service, clinicians who have an interest in breech birth should be supported to perform these roles within specialist teams.

CONCLUSIONS

Specialist breech teams may facilitate the development of expertise within maternity care settings. Evaluation of expertise based on enablement of women and colleagues, as well as outcomes, will potentially avoid the pitfalls of alienation produced by some forms of specialist authority.

Uncommon complications of monochorionic twin pregnancies: Twin reversed arterial perfusion sequence

Introduction

Twin reversed arterial perfusion (TRAP) sequence occurs when there is one non-viable twin without cardiac structures and a viable pump twin that perfuses the acardiac mass. This study aims to investigate the management and immediate neonatal outcomes for monochorionic multiple pregnancies complicated by TRAP referred to the NSW Fetal Therapy Centre (NSW FTC).

Methods

Retrospective cohort study of multiple pregnancies referred to NSW FTC between April 2006 and April 2014, reviewing data for cases of TRAP sequence (n = 19, including two triplet cases) compared to a timeframe matched sample of uncomplicated monochorionic diamniotic (MCDA) twin pregnancies managed in the unit (n = 45).

Results

Primary management of the 19 TRAP cases was expectant management in 10 (53%), radiofrequency ablation (RFA) in 6 (32%), and bipolar cord coagulation, amniodrainage and termination of pregnancy in 1 case each. 1 of 6 RFA cases had pump twin demise <1 week post-procedure. Average gestation at birth (35.1 ± 5.0 vs. 35.0 ± 2.8 weeks) and mean birthweight (2157 ± 1019 g vs. 2245 ± 537 g) were similar between TRAP pump fetuses and uncomplicated MCDA cases. Pump twin survival was 81% (twins only) compared to 98% for uncomplicated MCDA twins (P = 0.02), and in 5 of 19 (26%) TRAP pregnancies the pump fetus had a congenital anomaly.

Conclusion

Mean gestational age at birth and mean birthweight were similar for both TRAP and uncomplicated MCDA pregnancies. TRAP cases, however, had higher perinatal mortality, and high rates of congenital anomaly. The overall neonatal outcome at NSW FTC for TRAP cases is similar to reported international outcomes.