Antepartum severe maternal morbidity: A population-based study of risk factors and delivery outcomes

Risk of Adverse Neonatal Events in Pregnancies Complicated by Severe Maternal Morbidity

OBJECTIVE

To investigate the risk of adverse neonatal events after a pregnancy complicated by severe maternal morbidity.

STUDY DESIGN

We analyzed a population-based cohort of deliveries in Quebec, Canada, from between 2006 and 2021. The main exposure measure was severe maternal morbidity comprising life-threatening conditions, such as severe hemorrhage, cardiac complications, and eclampsia. The outcome included adverse neonatal events, such as very preterm birth (gestational age <32 weeks), bronchopulmonary dysplasia, hypoxic ischemic encephalopathy, and neonatal death. Using log-binomial regression models, we estimated adjusted relative risks (RR) and 95% confidence intervals (CI) for the association between severe maternal morbidity and adverse neonatal events.

RESULTS

Among 1,199,112 deliveries, 29,992 (2.5%) were complicated by severe maternal morbidity and 83,367 (7.0%) had adverse neonatal events. Severe maternal morbidity was associated with 2.96 times the risk of adverse neonatal events compared with no morbidity (95% CI 2.90-3.03). Associations were greatest for mothers who required assisted ventilation (RR 5.86, 95% CI 5.34-6.44), experienced uterine rupture (RR 4.54, 95% CI 3.73-5.51), or had cardiac complications (RR 4.39, 95% CI 3.98-4.84). Severe maternal morbidity was associated with ≥3 times the risk of neonatal death and hypoxic-ischemic encephalopathy and ≥10 times the risk of very preterm birth and bronchopulmonary dysplasia.

CONCLUSIONS

Severe maternal morbidity is associated with an elevated risk of adverse neonatal events. Better prevention of severe maternal morbidity may help reduce burden of severe neonatal morbidity.

Global burden of potentially life-threatening maternal conditions: a systematic review and meta-analysis

BACKGROUND

Potentially life-threatening maternal conditions (PLTCs) is an important proxy indicator of maternal mortality and the quality of maternal health services. It is helpful to monitor the rates of severe maternal morbidity to evaluate the quality of maternal care, particularly in low- and lower-middle-income countries. This study aims to systematically identify and synthesize available evidence on PLTCs.

METHODS

We searched studies in English from 2009‒2023 in PubMed, the National Library of Medicine (NLM) Gateway, the POPLINE database, and the Science Direct website. The study team independently reviewed the illegibility criteria of the articles. Two reviewers independently appraised the included articles using the Joanna Briggs Instrument for observational studies. Disputes between the reviewers were resolved by consensus with a third reviewer. Meta-analysis was conducted in Stata version 16. The pooled proportion of PLTCs was calculated using the random effects model. The heterogeneity test was performed using the Cochrane Q test, and its level was determined using the I2 statistical result. Using Egger's test, the publication bias was assessed.

RESULT

Thirty-two cross-sectional, five case-control, and seven cohort studies published from 2009 to 2023 were included in the meta-analysis. The highest proportion of PLTC was 17.55% (95% CI: 15.51, 19.79) in Ethiopia, and the lowest was 0.83% (95% CI: 0.73, 0.95) in Iraq. The pooled proportion of PLTC was 6.98% (95% CI: 5.98-7.98). In the subgroup analysis, the pooled prevalence varied based on country income level: in low-income 13.44% (95% CI: 11.88-15.00) I2 = 89.90%, low-middle income 7.42% (95% CI: 5.99-8.86) I2 = 99.71%, upper-middle income 6.35% (95% CI: 4.21-8.50) I2 = 99.92%, and high-income 2.67% (95% CI: 2.34-2.99) I2 = 99.57%. Similarly, it varied based on the diagnosis criteria; WHO diagnosis criteria used 7.77% (95% CI: 6.10-9.44) I2 = 99.96% at P = 0.00, while the Centers for Disease Controls (CDC) diagnosis criteria used 2.19% (95% CI: 1.89-2.50) I2 = 99.41% at P = 0.00.

CONCLUSION

The pooled prevalence of PLTC is high globally, predominantly in low-income countries. The large disparity of potentially life-threatening conditions among different areas needs targeted intervention, particularly for women residing in low-income countries. The WHO diagnosis criteria minimize the underreporting of severe maternal morbidity.

TRIAL REGISTRATION

CRD42023409229.