A decrease in subsequent births after severe maternal morbidity has been reported.

Reported reduction in subsequent births after severe maternal illness | Image credit: © Dimid – © Dimid – Stock.adobe.com.

Women who have severe maternal morbidity (SMM) during their first pregnancy are less likely to have subsequent pregnancies, according to a recent study published in . jam.¹

SMM is defined as a life-threatening event that occurs during pregnancy, childbirth, and up to 42 days postpartum. Sweden reported a combined SMM rate of 270.2 per 10,000 deliveries from 1999 to 2019.

Women may experience persistent health problems after SMM. These include reproductive challenges that can affect future fertility. A small study has found a potential link between SMM at first birth and increased risk of common and reproductive health problems after pregnancy.

Currently, there is a lack of data on the association between SMM at first birth and the probability of subsequent births. Therefore, researchers conducted a population-based retrospective cohort study to quantify this association.

The Swedish Medical Birth Register (MBR) has been cross-linked with the nationwide National Patient Register (NPR) for data on births in Sweden from 2019 to 2021. Data on antenatal, obstetric, and neonatal care were obtained from the MBR, and data on inpatient admissions were obtained from the MBR. NPR alerted me.

The basis for the diagnosis was International Statistical Classification of Diseases and Related Health Problems, 10th Edition code. Women who had given birth for the first time during the study period were included, and exclusion criteria included hysterectomy at first delivery, missing gestational age or sex, and missing maternal age.

All SMMs from 22 weeks of gestation to 42 days postpartum were reported as primary exposures. SMM was defined in 14 different types based on the validated SMM definition used for maternal health surveillance in Sweden.

Subsequent births were reported as the primary outcome and were determined using MBR records from 1999 to 2021. For stillbirths, data from 28 weeks of gestation onwards were available until July 1, 2008, and thereafter data from 22 weeks of gestation onwards. Relevant maternal characteristics were obtained from the MBR.

The final analysis included 1,046,974 women, of whom 3.5% presented with SMM at their first birth. These patients were more likely to be older and shorter, and to have higher BMI, pre-pregnancy hypertension, diabetes, and use of assisted reproductive technology compared to patients without SMM.

Fertility rates subsequently decreased significantly, 136.6 per 1000 person-years versus 182.4 per 1000 person-years for SMM and non-SMM women, respectively. After adjusting for maternal characteristics, the adjusted hazard ratio (aHR) for subsequent live births was reported to be 0.88.

This association was found regardless of SMM type. However, more significant reductions in the odds of subsequent birth were reported for cardiac complications, severe uterine rupture, and severe mental health conditions, with aHRs of 0.49, 0.48, and 0.48, respectively.

These results indicate that women with SMM during their first pregnancy have a lower probability of having a subsequent birth. The researchers recommended improved reproductive counseling and monitoring for women with SMM.

“Clinical monitoring of these women is essential and they require individualized advice about the possibility of future pregnancies,” said Eleni Zamantioti, a PhD student at Karolinska Institutet and lead author of the study. .² Sweden has observed a steady decline in birth rates over time, highlighting the importance of addressing reproductive health.

References

1. Tsamantioti E, Sandstrom A, Lindblad Wollmann C, Snowden JM, Razaz N. Association between severe maternal morbidity and subsequent live births. Japan Automobile Manufacturers Association. 2024.doi:10.1001/jama.2024.20957
2. Women who suffer from pregnancy complications have fewer children. Karolinska Institutet. November 25, 2024. Accessed November 25, 2024. https://www.eurekalert.org/news-releases/1065748