Severe maternal morbidity during first birth reduces chances of future births

First-time mothers who sustain life-threatening events during pregnancy, delivery, and up to 42 days postpartum are less likely to have more children, as suggested in a large retrospective study.

Researchers looked at 1,046,974 women in Sweden who had their first birth. They used the Swedish Medical Birth Register and National Patient Register to identify severe maternal morbidity (SMM) and SMM subtypes.  

Multivariable Cox proportional hazards regression was applied to examine associations between SMM and time to subsequent birth. Additionally, sibling analysis was conducted to assess potential genetic and familial confounding.

Of the women, 36,790 (3.5 percent) had an SMM event during their first birth. Women with vs without SMM tended to be older, be shorter, have higher BMI, have pregestational hypertension and diabetes, and have undergone assisted reproductive technology treatment.

The incidence rate of subsequent birth was lower among women with any SMM than among those who did not have any (136.6 vs 182.4 per 1,000 person-years; adjusted hazard ratio [aHR], 0.88, 95 percent confidence interval [CI], 0.87–0.89).

Looking at SMM subtypes, the probability of subsequent birth was especially lower among women with severe uterine rupture (aHR, 0.48, 95 percent CI, 0.27–0.85), cardiac complications (aHR, 0.49, 95 percent CI, 0.41–0.58), cerebrovascular accident (aHR, 0.60, 95 percent CI, 0.50–0.73), and severe mental health conditions (aHR, 0.48, 95 percent CI, 0.44–0.53).

Sibling analysis showed that the associations were not influenced by familial confounding.

The findings underscore the importance of providing adequate reproductive counselling and enhancing antenatal care for women with a history of SMM.