INTRODUCTION: Severe obstetric complications increase by the number of previous cesarean deliveries. In the Nordic countries most women have two children. We present the risk of severe obstetric complications at the delivery following a first elective or emergency cesarean and the risk by intended mode of second delivery.

MATERIAL AND METHOD: A two-year population-based data-collection of severe maternal complications in women with two deliveries in the Nordic countries (n=213 518). Denominators were retrieved from the national medical birth registers.

RESULTS: Out of 35 450 first cesarean deliveries (17%), 75% were emergency and 25% elective. Severe complications at second delivery were more frequent in women with a first cesarean than a first vaginal delivery and rates of abnormally invasive placenta, uterine rupture and severe postpartum hemorrhage were higher after a first elective than a first emergency cesarean delivery (RR 4.1 CI; 2.0-8.1, RR 1.8 CI; 1.3-2.5, RR 2.3 CI; 1.5-3.5). A first cesarean accounted for up to 97% of the severe complications in the second pregnancy. Induction of labor was associated with an increased risk of uterine rupture and severe hemorrhage.

CONCLUSION: Elective repeat cesarean nearly prevents complete uterine rupture at the second delivery, while the risk of severe obstetric hemorrhage, abnormally invasive placenta and peripartum hysterectomy is unchanged by the intended mode of second delivery in women with a first cesarean. Women with a first elective versus emergency cesarean have increased risk of severe complications in the second pregnancy. This article is protected by copyright. All rights reserved.