Outcomes of non-vertex second twins, following vertex vaginal delivery of first twin: a secondary analysis of the WHO Global Survey on maternal and perinatal health.
BACKGROUND
Mode of delivery remains a topic of debate in vertex/non-vertex twin pregnancies. We used the WHO Global Survey dataset to determine the risk of adverse maternal/perinatal outcomes associated with presentation of the second twin, following vaginal delivery of a vertex first twin.


METHODS
We analysed a derived dataset of twin pregnancies ≥ 32 weeks gestation where the first twin was vertex and delivered vaginally. Maternal, delivery and neonatal characteristics and adverse outcomes were reported by presentation of the second twin. Logistic regression models (adjusted for maternal and perinatal confounders, mode of delivery and region) were developed to determine odds of adverse outcomes associated with presentation.


RESULTS
1,424 twin pregnancies were included, 25.9% of these had a non-vertex second twin and Caesarean was more common in non-vertex presentations (6.2% vs 0.9%, p < 0.001). While the odds of Apgar < 7 at 5 minutes were higher in non-vertex presenting second twins (16.0% vs 11.4%, AOR 1.42 95% CI 1.01-2.00), the odds of maternal ICU admission (4.6% vs 1.7%, AOR 1.30, 95% CI 0.88-1.94), blood transfusion (6.0% vs 3.4%, AOR 1.23, 95% CI 0.67-2.25), stillbirth (7.6% vs 4.7%, AOR 1.15, 95% CI 0.72-1.73), early neonatal death (3.8% vs 2.1%, AOR 1.68, 95% CI 0.96-2.94), and NICU admission (26.6% vs 23.2%, AOR 0.93, 95% CI 0.62-1.39) were not.


CONCLUSIONS
After a vaginal delivery of a vertex first twin, non-vertex presentation of the second twin is associated with increased odds of Apgar <7 at 5 minutes, but not of other maternal/perinatal outcomes. Presentation of the second twin is not as important a consideration in planning twin vaginal birth as previously considered.
School of Population Health, Faculty of Medicine, Dentistry and Health Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia. vogeljo@who.int.
Joshua P
JP
Vogel
Erica
E
Holloway
Cristina
C
Cuesta
Guillermo
G
Carroli
João Paulo
JP
Souza
Jon
J
Barrett
D000328:Adult; D000349:Africa / Q000453:epidemiology; D001034:Apgar Score; D001208:Asia / Q000453:epidemiology; D001803:Blood Transfusion; D002585:Cesarean Section; D005260:Female; D006306:Health Surveys; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D015931:Intensive Care, Neonatal; D007746:Labor Presentation; D007843:Latin America / Q000453:epidemiology; D007744:Obstetric Labor Complications / Q000453:epidemiology* / Q000628:therapy; D036801:Parturition; D011247:Pregnancy; D059285:Pregnancy, Twin; D050497:Stillbirth / Q000453:epidemiology; D014944:World Health Organization; D055815:Young Adult