Severe Maternal Morbidity and Infant Mortality in Canada

Association between stillbirth and severe maternal morbidity

BACKGROUND

Severe maternal morbidity has been increasing in the past few decades. Few studies have examined the risk of severe maternal morbidity among individuals with stillbirths vs individuals with live-birth deliveries.

OBJECTIVE

This study aimed to examine the prevalence and risk of severe maternal morbidity among individuals with stillbirths vs individuals with live-birth deliveries during delivery hospitalization as a primary outcome and during the postpartum period as a secondary outcome.

STUDY DESIGN

This was a retrospective cohort study using birth and fetal death certificate data linked to hospital discharge records from California (2008-2018), Michigan (2008-2020), Missouri (2008-2014), Pennsylvania (2008-2014), and South Carolina (2008-2020). Relative risk regression analysis was used to examine the crude and adjusted relative risks of severe maternal morbidity along with 95% confidence intervals among individuals with stillbirths vs individuals with live-birth deliveries, adjusting for birth year, state of residence, maternal sociodemographic characteristics, and the obstetric comorbidity index.

RESULTS

Of the 8,694,912 deliveries, 35,012 (0.40%) were stillbirths. Compared with individuals with live-birth deliveries, those with stillbirths were more likely to be non-Hispanic Black (10.8% vs 20.5%); have Medicaid (46.5% vs 52.0%); have pregnancy complications, including preexisting diabetes mellitus (1.1% vs 4.3%), preexisting hypertension (2.3% vs 6.2%), and preeclampsia (4.4% vs 8.4%); have multiple pregnancies (1.6% vs 6.2%); and reside in South Carolina (7.4% vs 11.6%). During delivery hospitalization, the prevalence rates of severe maternal morbidity were 791 cases per 10,000 deliveries for stillbirths and 154 cases per 10,000 deliveries for live-birth deliveries, whereas the prevalence rates for nontransfusion severe maternal morbidity were 502 cases per 10,000 deliveries for stillbirths and 68 cases per 10,000 deliveries for live-birth deliveries. The crude relative risk for severe maternal morbidity was 5.1 (95% confidence interval, 4.9-5.3), whereas the adjusted relative risk was 1.6 (95% confidence interval, 1.5-1.8). For nontransfusion severe maternal morbidity among stillbirths vs live-birth deliveries, the crude relative risk was 7.4 (95% confidence interval, 7.0-7.7), whereas the adjusted relative risk was 2.0 (95% confidence interval, 1.8-2.3). This risk was not only elevated among individuals with stillbirth during the delivery hospitalization but also through 1 year after delivery (severe maternal morbidity adjusted relative risk, 1.3; 95% confidence interval, 1.1-1.4; nontransfusion severe maternal morbidity adjusted relative risk, 1.2; 95% confidence interval, 1.1-1.3).

CONCLUSION

Stillbirth was found to be an important contributor to severe maternal morbidity.

Associations Between State-Level Severe Maternal Morbidity and Other Perinatal Indicators

This cross-sectional study examines state-level associations between severe maternal morbidity and other perinatal indicators, including prepregnancy hypertension, prepregnancy diabetes, prepregnancy obesity, low-risk cesarean delivery, preterm birth, and maternal and infant mortality.

The effect of severe maternal morbidity on infant costs and lengths of stay

OBJECTIVE

To examine the association between severe maternal morbidity (SMM) and infant health using the additional infant costs and length of stay (LOS) as markers of added clinical complexity.

STUDY DESIGN

Secondary data analysis using California linked birth certificate-patient discharge data for 2009-2011 (N = 1,260,457). Regression models were used to estimate the association between SMM and infant costs and LOS.

RESULTS

The 16,687 SMM-exposed infants experienced a $6550 (33%) increase in costs and a 0.7 (18%) day increase in LOS. Preterm infants had ($11,258 (18%) added costs and 1.3 days (8.1%) longer LOS) than term infants ($2539 (38%) added costs and 0.5 days (22%) longer LOS).

CONCLUSIONS

SMM was associated with increased infant costs and LOS, suggesting that SMM may have adverse health effects for infants, including term infants. The relatively larger effect on costs indicates an increase in treatment intensity (clinical severity) greater than additional LOS.

Perinatal Risks of Neonatal and Infant Mortalities in a Sub-provincial Region of China: A Livebirth Population-based Cohort Study

Background

Current vital statistics of birth population and neonatal outcome in China lacked information and definition of deaths at delivery and during hospitalization, especially for extreme preterm (EPT) birth. This study aims to delineate the prevalence of neonatal hospitalization, neonatal and infant mortality rates (NMR, IMR) and associated perinatal risks based on all livebirths in Huai’an, an evolving sub-provincial region in eastern China.

Methods

This retrospective cohort study established a comprehensive database linking information of whole regional livebirths and neonatal hospitalization in 2015, including deaths at delivery and EPT livebirths. The primary outcomes were NMR and IMR stratified by gestational age (GA) and birthweight (BW) with 95% confidence intervals. Causes of the neonatal and infant deaths were categorized according to the International Statistical Classification of Diseases 10th version, and population attributable fractions of GA and BW strata were analyzed. Perinatal risks of infant mortalities in continuum periods were estimated by Cox regression models.

Results

Among the whole livebirth population (59056), 7960 were hospitalized (prevalence 13.5%), with 168 (2.8‰) in-hospital deaths. The NMR was 3.6 (3.2, 4.1)‰ and IMR 4.9 (1.4, 4.5)‰, with additionally 35 (0.6‰) deaths at delivery. The major causes of infant deaths were perinatal conditions (2.6‰, mainly preterm-related), congenital anomalies (1.5‰), sudden unexpected death in infancy (0.6‰) and other causes (0.2‰). The deaths caused by preterm and low BW (LBW) accounted for 50% and 40% of NMR and IMR, with 20-30% contributed by EPT or extremely LBW, respectively. Multivariable Cox regression analysis revealed that peripartum factors and LBW strata had strong association with early- and late-neonatal deaths, whereas those of GA < 28 weeks were highly associated with postneonatal deaths. Congenital anomalies and neonatal hospitalization remained high death risks over the entire infancy, whereas maternal co-morbidities/complications were modestly associated with neonatal but not postneonatal infant mortality.

Conclusions

The NMR, IMR, major causes of deaths and associated perinatal risks in continuum periods of infancy, denote the status and quality improvement of the regional perinatal-neonatal care associated with socioeconomic development. The study concept, applicability and representativeness may be validated in other evolving regions or countries for genuine comparison and better maternal-infant healthcare.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04653-8.

Escalating Care on Labor and Delivery

Maternal morbidity and mortality are rising due in part to the rising prevalence of chronic illness, socioeconomic and racial disparities, and advanced maternal age. Prevention of maternal adverse outcomes requires prompt escalation of care to facilities with appropriate capabilities including intensive care services. The development of obstetrical-specific risk assessment tools and protocolized care for the most common causes of maternal intensive care unit (ICU) admission has helped to reduce preventable complications. However, significant work remains to address barriers to the escalation of maternal care and minimize delays in appropriate management.