Association between Timing of COVID-19 Diagnosis in Pregnancy and Maternal-Fetal Outcomes: A Retrospective Study.

Objective: To examine the relationship between COVID-19 diagnosis timing during pregnancy and adverse maternal and fetal outcomes.

Methods: Pregnant women diagnosed with COVID-19 by a nasopharyngeal swab SARS-CoV-2 PCR between January 1, 2021, and December 31, 2021, irrespective of the pregnancy outcome, were included in the study. Patients not diagnosed with COVID-19 were included as a comparison group. The timing of COVID diagnosis was categorized by trimester (first trimester, <13 weeks; second trimester, 13 to <27 weeks; third trimester, >27 weeks). Maternal outcomes included placental abnormalities, HELLP syndrome, deep vein thrombosis, pulmonary embolism, and maternal death. Fetal outcomes included pregnancy loss, intrauterine growth restriction, preterm birth, stillbirth, and admission to the NICU. Quantitative data were analyzed using a one-way ANOVA and are presented as mean ± standard deviation (SD). Nominal data were compared using chi-square or Fisher's exact tests and are reported as frequency (percent). Statistical significance was set at p < 0.05.

Results: A total of 289 COVID-affected pregnancies and 1706 non-COVID-19 pregnancies were included. Most patients, 189 (65.4%), were diagnosed with COVID-19 in the third trimester, 66 (22.8%) in the second trimester, and 34 (11.8%) in the first trimester. There was a statistically significant higher proportion of patients experiencing placental abnormalities in patients diagnosed with COVID-19 in the 3rd trimester with lowest occurrence in non-COVID-19 pregnancies, followed by patients diagnosed in the 1st and 2nd trimesters (p<0.001). Further, preterm delivery followed a similar frequency pattern, occurring most often in patients diagnosed with COVID-19 in the 3rd trimester (p<0.001).

Conclusion: Patients with COVID-19 infection in the third trimester of pregnancy face a heightened risk of adverse maternal-fetal outcomes. Further investigation into this relationship is warranted.