Pregnancy before recurrent pregnancy loss more often complicated by post-term birth and perinatal death

The cause of recurrent pregnancy loss often remains unknown. Possibly, pathophysiological pathways are shared with other pregnancy complications.

All women with secondary recurrent pregnancy loss (SRPL) visiting Leiden University Medical Center (January 2000-2015) were included in this retrospective cohort to assess whether women with SRPL have a more complicated first pregnancy compared with control women. SRPL was defined as three or more consecutive pregnancy losses before 22 weeks of gestation, with a previous birth. The control group consisted of all Dutch nullipara delivering a singleton (January 2000-2015). Information was obtained from the Dutch Perinatal Registry. Outcomes were preeclampsia, preterm birth, post-term birth, intrauterine growth restriction, breach position, induction of labor, cesarean section, congenital abnormalities, perinatal death and severe hemorrhage in the first ongoing pregnancy. Subgroup analyses were performed for women with idiopathic SRPL and for women ≤35 years.

In all, 172 women with SRPL and 1 196 178 control women were included. Women with SRPL were older and had a higher body mass index; 29.7 years vs. 28.8 years and 25.1 kg/m² vs. 24.1 kg/m² , respectively. Women with SRPL more often had a post-term birth (OR 1.86, 95% CI 1.10-3.17) and more perinatal deaths occurred in women with SRPL compared with the control group (OR 5.03, 95% CI 2.48-10.2). Similar results were found in both subgroup analyses.

The first ongoing pregnancy of women with (idiopathic) SRPL is more often complicated by post-term birth and perinatal death. Revealing possible links between SRPL and these pregnancy complications might lead to a better understanding of underlying pathophysiology.