Pregnancy outcomes after SARS-CoV-2 infection by trimester: A large, population-based cohort study

Abstract

Objectives Data regarding women infected with SARS-CoV-2 during early trimesters are scarce. We aimed to assess preterm birth (PTB) and small-for-gestational-age (SGA) rates in a large and unselected cohort by trimester at infection and overall. Design A retrospective cohort study including all women with a positive SARS-CoV-2 RT-PCR test during a non-ectopic singleton pregnancy between February 21st 2020 and July 2nd 2021 (N = 2753). Each infected woman was matched to a non-infected pregnant woman by age, last menstruation date, sector, and socioeconomic status. Methods Logistic regression was conducted to assess the risks of PTB and SGA including an interaction between group and trimester of infection. Multivariable models included underlying diseases, previous abortions and null parity. Subgroup analyses were conducted on symptomatic infected women and matched non-infected women. Results A total of 2753 /2789 (98.7%) eligible women that were infected during pregnancy could be matched, among them, 17.4% and 48.4% were infected during the first and third trimesters, respectively. While first and second trimester infections were not associated with PTB (p>0.8), third trimester infections and in particular after 34 weeks of gestation had a greater risk of PTB with adjusted ORs of 2.76 (95% CI 1.63–4.67) and 7.10 (95% CI 2.44–20.61), respectively. PTB risk was further heightened in symptomatic third trimester infections (OR = 4.28, 95% CI 1.94–9.25). SGA risk was comparable between study groups across all trimesters of infection. Pregnancy loss incidence was similar in both groups (adjusted OR = 1.16; 95% CI 0.90–1.50). Conclusion SARS-CoV-2 infection was associated with increased risk of PTB only among women infected during late pregnancy, particularly among symptomatic women.

COVID-19 and pregnancy: clinical outcomes; mechanisms, and vaccine efficacy

“…Recently, a large cohort study indicated that the SARS-CoV-2 infection during third trimester is significantly associated with preterm births as compared to matched non-infected controls. 100 First and second trimester infections did not cause any adverse pregnancy outcomes when compared to non-infected controls. This study emphasizes the importance of gestational age at SARS-CoV-2 infection in determining the outcome of the pregnancy.…”

The impact of maternal SARS-CoV-2 infection and COVID-19 vaccination on maternal-fetal outcomes

“… [7] , [10] , [11] , [12] , [13] , [14] , [16] , [18] , [19] , [30] , [31] , [33] , [36] , [38] , [53] Multiple studies report an increased risk of premature birth even after adjusting for common cofactors. [11] , [12] , [14] , [18] , [31] , [37] , [53] , [54] Preterm birth is also significantly more likely following COVID-19 in a high-risk pregnancy compared to an infection in a low-risk pregnancy. [28] In addition, several of these studies considered preterm birth in the context of infection severity with mixed reports on how COVID-19 severity impacted preterm birth risk.…”

“…Babies born to people with COVID-19 during pregnancy weighed significantly less at delivery. [12] , [13] , [18] , [38] , [54] , [59] There were mixed reports about whether COVID-19 during pregnancy impacted the relative risk for SGA with one study reporting a 1.3 fold increase, [18] one study recording a 0.9 fold decrease, [59] and four noting no change ( Table 4 ). [12] , [13] , [30] , [54] Babies born to mothers with COVID-19 during pregnancy were also 1.2-2.4 fold more likely to be admitted to the NICU ( Table 4 ).…”

“… [12] , [13] , [18] , [38] , [54] , [59] There were mixed reports about whether COVID-19 during pregnancy impacted the relative risk for SGA with one study reporting a 1.3 fold increase, [18] one study recording a 0.9 fold decrease, [59] and four noting no change ( Table 4 ). [12] , [13] , [30] , [54] Babies born to mothers with COVID-19 during pregnancy were also 1.2-2.4 fold more likely to be admitted to the NICU ( Table 4 ). [26] , [37] , [59] Most studies report increased risk for neonatal death, perinatal death, or stillbirth following a maternal SARS-CoV-2 infection, however there are mixed results ( Table 4 ).…”

El enigma del coronavirus – ¿El final de la pandemia COVID-19? – La mujer, la gestante y el feto – Vacunas - Futuro

“…El riesgo de pequeño para edad gestacional fue comparable entre los grupos de estudio en todos los trimestres de la infección, y la pérdida del embarazo fue similar en ambos grupos. La infección por SARS-CoV-2 se asoció con un mayor riesgo de PPT solo entre las mujeres infectadas durante el último trimestre del embarazo, particularmente entre las mujeres sintomáticas (18) .…”