1 Aalborg University Hospital, The Faculty of Medicine, Aalborg University, VBN2 Klinik Kvinde-Barn og Urinvejskirurgi, The Faculty of Medicine, Aalborg University, VBN3 Gynækologi, Graviditet og Fødsel (Gynækologi og Obstetrik), The Faculty of Medicine, Aalborg University, VBN4 Department of Clinical Medicine, The Faculty of Medicine, Aalborg University, VBN5 The Faculty of Medicine, Aalborg University, VBN6 2nd Department of Obstetrics and Gynecology7 Medical Consultant in the Department of Fetal Medicine8 Medical Consultant at the Department of Obstetrics and Gynecology9 Fetal Medicine Unit
A Population-Based Study of Occurrence and Outcome
BACKGROUND: Although management of twin deliveries has been a topic of discussion for decades, a consensus on how to deliver twins is lacking. The objective of this study was to examine short-term neonatal outcome of the second twin delivered by cesarean section after vaginal delivery of the first-born twin (combined delivery) and to identify predictors of combined delivery. METHODS: This study was a 3-year, population-based, retrospective cohort investigation of 1,254 twin births in Denmark. The twin births were divided into three groups: vaginal deliveries, planned cesarean deliveries, and combined deliveries. Data were extracted from medical records, a fetal medicine software program (Astraia), and the National Birth Registry. Short-term poor neonatal outcome was measured as a 5-minute Apgar score ≤ 7, umbilical cord pH ≤ 7.10, and admission to neonatal intensive care unit for more than 3 days. RESULTS: Vertex-nonvertex fetal presentations were more prevalent in combined deliveries than vaginal deliveries (OR 4.4, 2.5-7.8). Nonvertex second twins born by combined delivery had a higher risk of Apgar score ≤ 7 and umbilical cord pH ≤ 7.10 compared with vaginal delivery, unadjusted OR 6.2 (2.1-18), and unadjusted OR 3.9 (1.6-9.5). Prenatal ultrasound scans were evaluated in combined deliveries, of which 48 percent were vertex-vertex at the last ultrasound scan in pregnancy (mean gestational age 34 + 0) and 37 percent were vertex-vertex at birth. CONCLUSIONS: Vertex-nonvertex presenting twins have an increased risk of combined delivery. Combined deliveries are associated with increased neonatal morbidity for the second twin.