SARS-CoV-2 Maternal and Perinatal Outcomes

SARS-CoV-2 infection during pregnancy may be significantly associated with an increased risk of adverse maternal outcomes ie, disease requiring hospitalization, admission to an intensive care unit/critical care unit, and/or oxygen therapy and preterm birth, a recent study published in the JAMA Networkhas indicated.

The authors looked at Canadian Surveillance of COVID-19 in Pregnancy (CANCOVID- Preg), the national surveillance program for SARS-CoV-2–affected pregnancies in Canada.    

The analysis presented exploratory, population-level data from 6 Canadian provinces for the period of March 1, 2020, to October 31, 2021. A total of 6012 pregnant persons with a positive SARS-CoV-2 polymerase chain reaction test result at any time in pregnancy were included and compared with 2 contemporaneous groups including age-matched female individuals with SARS-CoV-2 and unaffected pregnant persons from the pandemic time period.

Canadian national population-level outcome data from Statistics Canada of all-female, SARS-CoV-2–positive individuals aged 20 to 49 years were used for comparison with their cohort of pregnant individuals.

Among 6012 pregnancies with complete information about a SARS-CoV-2–related hospitalization or ICU admission, 466 (7.75%) had a hospitalization, 207 (3.4%) required oxygen therapy, and 121 (2.01%) had an ICU admission. When compared with female individuals aged 20 to 49 years in Canada diagnosed with SARS-CoV-2, patients with SARS-CoV-2 during pregnancy were at significantly increased risk of hospitalization.

None of the patients who had received at least 2 doses of a SARS-CoV-2 vaccine experienced any of the adverse maternal outcomes. With their analysis, the authors noted the following

● Among pregnant SARS-CoV-2–positive individuals, increasing age was associated with a significantly increased risk of ICU admission.

● The presence of preexisting hypertension resulted in a significantly increased risk of requiring oxygen therapy.

● Greater gestational age at diagnosis was associated with a significantly greater risk of hospitalization and oxygen therapy; among infections diagnosed at 28 weeks gestation or greater vs infections diagnosed at 15 to 27 weeks gestation.

● Body mass index, type 1 or 2 diabetes, asthma, and race and ethnicity were also significantly associated with an increased risk of adverse maternal outcomes.

● The median length of hospital stay was 6 days.

● The median length of ICU stay was 4 days.

● The median time between hospital admission and delivery was 34 days.

● Rates of preeclampsia, cesarean delivery, and stillbirth did not differ significantly between SARS-CoV-2–affected and unaffected pregnancies in Canada.

● The rate of overall preterm birth (<37 weeks' gestation) among SARS-CoV- 2–affected pregnancies was 11.1%, compared with 6.8% among all unaffected Canadian pregnancies. Of 175 preterm births with detailed delivery information, 46% were spontaneous and 54% were medically indicated. Preterm birth occurred at an elevated rate, even in cases of mild disease not requiring hospitalization (9.3%). the authors wrote.

"Unlike other studies that have solely relied on the identification of infection at delivery and miss cases that resolve during pregnancy, this study captured SARS-CoV-2 infections throughout gestation. Additionally, this analysis was able to compare cumulative incidence of pregnancy and birth outcomes from a comprehensive cohort of SARS-CoV-2–affected pregnancies with national-level data on all pregnancies to quantify the differential risks of pregnancy outcomes associated with SARS-CoV-2" "In this exploratory surveillance study conducted in Canada from March 2020 to October 2021, SARS-CoV-2 infection during pregnancy was significantly associated with increased risk of adverse maternal outcomes and preterm birth," they concluded.