SARS-CoV-2 tied to increased obstetric-related morbidity, mortality

SARS-CoV-2 infection during pregnancy or the postpartum period is tied to an increased risk of maternal mortality or serious morbidity due to obstetric complications, a study from the US showed.

This retrospective cohort study included 14,104 pregnant and postpartum individuals (mean age 29.7 years) with singleton or twin gestation who delivered between March and December, 2020, at 17 hospitals in the US. The 2,352 individuals with a positive SARS-CoV-2 test (during pregnancy or within 6 weeks postpartum) were compared with the 11,752 without a positive test (negative test or no documented infection during pregnancy). Individuals who tested positive during pregnancy most often did so during the third trimester (80.1 percent). Among the 103 individuals who tested positive postpartum, median time of positive test was 18 days post-delivery.

The composite outcome of maternal any-cause death or serious morbidity related to hypertensive disorders of pregnancy, postpartum haemorrhage, or non–SARS-CoV-2 infection was significantly increased among those with vs without SARS-CoV-2 infection (13.4 percent vs 9.2 percent; adjusted relative risk [adjRR], 1.41, 95 percent confidence interval [CI], 1.23–1.61). [JAMA 2022;doi:10.1001/jama.2022.1190]

Conversely, the risk of Caesarean birth was not increased among individuals with vs without SARS-CoV-2 infection (34.7 percent vs 32.4 percent; adjRR, 1.05, 95 percent CI, 0.99–1.11).

There were five maternal deaths, all of which occurred among individuals with SARS-CoV-2 infection.

Individuals with SARS-CoV-2 infection had an increased risk of severe maternal morbidity or mortality and intensive care unit (ICU) admission compared with those without infection (adjRRs, 4.39 and 5.82, respectively). The need for mechanical ventilation or vasopressor support and incidence of cardiomyopathy and venous thromboembolism were elevated in those with vs without SARS-CoV-2 infection. No incidents of multisystem inflammatory syndrome were documented.

Infection severity affects outcomes

A total of 586 individuals had COVID-19 that was considered moderate, severe, or critical. The risk of the composite maternal death or serious morbidity outcome was increased in this group compared with those without SARS-CoV-2 infection (26.1 percent vs 9.2 percent; adjRR, 2.06). This group also had an increased risk of Caesarean birth (45.4 percent vs 32.4 percent; adjRR, 1.17), severe maternal morbidity and mortality (13.3 percent vs 1.4 percent; adjRR, 12.84), and ICU admission (12.8 percent vs 1.2 percent; adjRR, 16.98) vs those without SARS-CoV-2 infection.

The risk of the composite maternal death or serious morbidity outcome was not increased among individuals who had mild or asymptomatic COVID-19 compared with those without SARS-CoV-2 infection (9.2 percent in each group; adjRR, 1.11), nor was the risk of Caesarean birth (31.2 percent vs 32.4 percent; adjRR, 1.00). However, individuals who had mild or asymptomatic SARS-CoV-2 infection had elevated risks of superficial or deep surgical site infection (1.8 percent vs 0.7 percent; RR, 2.55) and hypertensive disorders of pregnancy (7.1 percent vs 6.5 percent; adjRR, 1.28).

SARS-CoV-2 impacts neonatal outcomes

A total of 14,471 neonates were included, 2,297 and 12,017 born to individuals with and without SARS-CoV-2 infection during pregnancy, respectively.

The risk of preterm birth (<37 weeks gestation) was increased among those born to individuals with vs without SARS-CoV-2 infection during pregnancy (17.7 percent vs 14.1 percent; adjRR, 1.15), as was the risk of neonatal ICU (NICU) admission (22.0 percent vs 17.8 percent; adjRR, 1.15).

About 59 percent of preterm births in the SARS-CoV-2 positive group were medically indicated or not due to spontaneous preterm labour, with COVID-19 being the indication in 8.3 percent. Of the 1,323 live births in the exposed group with a SARS-CoV-2 test, 1.2 percent of neonates tested positive for SARS-CoV-2 before discharge.

Individuals with moderate, severe, or critical COVID-19 had an increased risk of preterm birth and NICU admission vs those without SARS-CoV-2 infection, while the outcomes for those with mild or asymptomatic COVID-19 did not significantly vary from those without SARS-CoV-2 infection.

Timely care is vital

According to the authors, evidence on the association between SARS-CoV-2 and obstetric-related morbidity and mortality is scarce and conflicting.

“[In this study,] SARS-CoV-2 infection was associated with an increased risk for a composite outcome of maternal mortality or serious morbidity from obstetric complications,” they said.

“Prevention of serious morbidity related to these common complications relies on timely presentation to care, as well as appropriate monitoring and rapid intervention. Care modifications for pregnant individuals with SARS-CoV-2, such as limitations on in-person visits, isolation of infected individuals, and time for hospital staff to don necessary personal protective equipment, could all plausibly delay evaluation and treatment resulting in disease progression and morbidity,” they pointed out. In addition, COVID-19 infection could contribute to certain complications.

The authors noted that as data was obtained before circulation of the delta strain of SARS-CoV-2 as well as widespread SARS-CoV-2 vaccination campaigns, the findings may not apply to obstetric outcomes during the circulation of the omicron strain. Furthermore, most women tested positive during the third trimester and as such, “the observed morbidity may be related to virus acquisition surrounding the time of delivery,” the authors said.