INTRODUCTION: The aim of this study was to compare short-term maternal outcomes in healthy primiparous women with uncomplicated pregnancies who delivered a singleton child at term by planned cesarean or planned vaginal delivery.

MATERIAL AND METHODS: Nationwide population-based cohort study of 145 821 low-risk primiparous women with healthy singletons in cephalic position in Denmark, 2008-2016. Data from the Medical Birth Register and the Danish National Patient Registry were linked and compared according to planned mode of delivery. Main outcome measures were major morbidity including maternal death, cardiac arrest, hysterectomy and thromboembolic disease. Minor maternal morbidity includes wound infection, postpartum fever, wound rupture and reoperation, bladder lesions, spinal headache and Ogilvie syndrome. Additionally, anal sphincter injuries were registered.

RESULTS: The study included 141 782 planned vaginal deliveries and 4039 planned cesarean deliveries. Severe maternal complications occurred in fewer than 1/4000 in both categories. Women with planned cesarean had a slightly higher risk of wound infections (0.17% vs 0.07%; P = 0.04). There were no significant differences in the remaining minor and major outcomes. Women with planned vaginal delivery had a 4.97% risk of obstetric anal sphincter injuries.

CONCLUSIONS: For healthy primiparous women, both planned vaginal delivery and planned cesarean delivery are highly safe procedures when the short-term maternal outcome is taken into account. Planned cesarean delivery is associated with a slightly increased risk of wound infection compared with planned vaginal delivery. Women with planned vaginal delivery had a 4.97% risk of obstetric anal sphincter injuries.