Development and internal validation of a model predicting severe maternal morbidity using pre-conception and early pregnancy variables: a population-based study in Ontario, Canada

Risk of recurrent severe maternal morbidity: a population-based study

BACKGROUND

Severe maternal morbidity is a composite indicator of maternal health and obstetrical care. Little is known about the risk of recurrent severe maternal morbidity in a subsequent delivery.

OBJECTIVE

This study aimed to estimate the risk of recurrent severe maternal morbidity in the next delivery after a complicated first delivery.

STUDY DESIGN

We analyzed a population-based cohort study of women with at least 2 singleton hospital deliveries between 1989 and 2021 in Quebec, Canada. The exposure was severe maternal morbidity in the first hospital-recorded delivery. The study outcome was severe maternal morbidity at the second delivery. Log-binomial regression models adjusted for maternal and pregnancy characteristics were used to generate relative risks and 95% confidence intervals comparing women with and without severe maternal morbidity at first delivery.

RESULTS

Among 819,375 women, 43,501 (3.2%) experienced severe maternal morbidity in the first delivery. The rate of severe maternal morbidity recurrence at second delivery was 65.2 vs 20.3 per 1000 in women with and without previous severe maternal morbidity (adjusted relative risk, 3.11; 95% confidence interval, 2.96-3.27). The adjusted relative risk for recurrence of severe maternal morbidity was greatest among women who had ≥3 different types of severe maternal morbidity at their first delivery, relative to those with none (adjusted relative risk, 5.50; 95% confidence interval, 4.26-7.10). Women with cardiac complication at first delivery had the highest risk of severe maternal morbidity in the next delivery.

CONCLUSION

Women who experience severe maternal morbidity have a relatively high risk of recurrent morbidity in the subsequent pregnancy. In women with severe maternal morbidity, these study findings have implications for prepregnancy counseling and maternity care in the next pregnancy.

Prepregnancy Emergency Department Use and Risks of Severe Maternal and Neonatal Morbidity in Canada

IMPORTANCE

Emergency department (ED) use during pregnancy may be associated with worse obstetrical outcomes, possibly because of differences in access to health care. It is not known whether ED use before pregnancy is associated with serious adverse maternal and perinatal outcomes.

OBJECTIVE

To study the association between prepregnancy ED use and adverse maternal and perinatal outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study was conducted in Ontario, Canada, and included all livebirths and stillbirths from April 2003 to January 2020.

EXPOSURES

Main exposure was any ED encounter within 90 days preceding the start of the index pregnancy.

MAIN OUTCOMES AND MEASURES

Primary outcome was a composite of severe maternal morbidity (SMM) from 20 weeks' gestation to 42 days' post partum. Secondary outcomes included severe neonatal morbidity (SNM) from 0 to 27 days, neonatal death, and stillbirth. Relative risks (RRs) were adjusted for maternal age, income, and rurality.

RESULTS

Of 2 130 245 births, there were 2 119 335 livebirths (99.5%) and 10 910 stillbirths (0.5%). The mean (SD) maternal age was 29.6 (5.4) years, 212 478 (9.9%) were rural dwelling, and 498 219 (23%) had 3 or more comorbidities. Among all births, 218 011 (9.7%) had a prepregnancy ED visit. The rate of SMM was higher among women with a prepregnancy ED visit than those without (22.3 vs 16.5 per 1000 births), with an RR of 1.34 (95% CI, 1.30-1.38) and an adjusted RR (aRR) of 1.37 (95% CI, 1.33-1.42). Compared with no prepregnancy ED visit, the aRR was higher in those with 1 (1.29; 95% CI, 1.24-1.34), 2 (1.51; 95% CI, 1.42-1.61), and 3 or more (1.74; 95% CI, 1.61-1.90) ED visits. Prepregnancy ED visits for a hematological (aRR, 13.60; 95% CI, 10.48-17.64), endocrine (aRR, 4.96; 95% CI, 3.72-6.62), and circulatory (aRR, 2.27; 95% CI, 1.68-3.07) conditions were associated with the highest aRRs for SMM. The rate of SNM was higher among newborns whose mother visited the ED within 90 days before pregnancy (68.2 vs 55.4 per 1000 births; aRR, 1.24; 95% CI, 1.22-1.26) as was the risk of neonatal death (aRR, 1.26; 95% CI, 1.16-1.37) and stillbirth (aRR, 1.18; 95% CI, 1.11-1.25).

CONCLUSIONS AND RELEVANCE

In this study, ED use was common before pregnancy. These findings suggest that ED use may not only reflect a woman's access to prepregnancy care but also higher future risk of severe maternal and perinatal morbidity, potentially offering a useful trigger for health system interventions to decrease adverse pregnancy outcomes.

Association between Cardiorespiratory Fitness and Hypertensive Disorders of Pregnancy: A Systematic Review and Meta-Analysis

Hypertensive disorders of pregnancy (HDP) are associated with future cardiovascular disease (CVD), which may be mediated by diminished cardiorespiratory fitness (CRF). In this systematic review and meta-analysis, we summarize evidence linking CRF with HDP before, during, and after pregnancy. We searched relevant databases to identify observational or randomized studies that measured CRF (VO2 max or peak, VO2 at anaerobic threshold, or work rate at peak VO2) in women with and without HDP. We pooled results using random effects models. Fourteen studies (n = 2406 women) reporting on CRF before, during, and after pregnancy were included. Before pregnancy, women who developed HDP had lower CRF (e.g., VO2max < 37 vs. ≥37 mL O2/min) than those without HDP (two studies, 811 women). VO2max at 14−18 weeks of pregnancy was marginally lower among women who developed preeclampsia vs. normotensive women (three studies, 275 women; mean difference 0.43 mL/kg/min [95% CI 0.97, 0.10]). Postpartum, there was a trend towards lower VO2peak in women with previous preeclampsia (three studies, 208 women; 0.26 mL/kg/min [−0.54, 0.02]). While exploratory, our findings raise the possibility that CRF can identify women at risk for HDP, and furthermore, that HDP confers a hit to a woman’s cardiorespiratory reserve.