A Single-Center Cohort Study on 1663 Twin Births from Two Decades: Descriptive Statistics and General Trends

ABSTRACT Background: Twin pregnancies continue to be associated with increased perinatal morbidity and mortality. The aim of this study is to describe our experience with twin deliveries and provide this data as reference. Methods: In this retrospective study, twin deliveries occurring after 22+0 weeks of gestational age in the Department of Obstetrics and Gynecology, University Hospital Ulm were analyzed. 1663 datasets (including 3326 children) were available for analysis. Results: Over time there was an average of 83 twin births per year (median 80, range 56 - 104) in our department, with a significant increase in the number of twin births per year over time (n = 20, rs = 0.821, p < 0.001). The average maternal age was 31 years (range 17 - 47), and in the time frame maternal age significantly increased (rs = 0.167, p < 0.001). The median gestational age at delivery was 35 weeks (range 22+0 - 42+0 weeks). Overall, 400 (20.1%) twin births had a planned/elective cesarean section (C/S). In 575 (34.6%) cases both twins were delivered vaginally and in 641 (38.5%) cases both twins were delivered by secondary (unplanned / emergency) C/S. In 47 (2.8%) cases, the first twin was born vaginally, and the second twin by secondary C/S. Of the 575 vaginal twin births, both twins were born spontaneously in 471 (81.9%) and by assisted vaginal delivery in 24 (4.2%) cases. In 53 (9.2%) cases the first twin was born by assisted vaginal delivery while the second twin was born spontaneously, and for 27 (4.7%) twin births this pattern was reversed. Conclusions: The optimal mode of delivery of twins is still a subject of continuing debate. Though the database provides very detailed information on the delivery it is not possible to draw clinical conclusions from our results as these need to be evaluated in prospective randomized trials. Keywords: Gemini, Twin, Delivery, Outcome, Retrospective, Pregnancies