Comparison of Maternal and Perinatal Outcomes Associated with Delta (B.1.617.2) and Other Variants of Severe Acute Respiratory Syndrome-Coronavirus 2.

Objective: To compare the frequency of adverse maternal and perinatal outcomes associated with delta (B.1.617.2) and other variants of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2).

Study design: An observational study. Place and Duration of the Study: Bursa City Hospital, Bursa, Turkey, from March 2020 to February 2022.

Methodology: The study included 423 pregnant women diagnosed with COVID-19 based on real-time reverse transcriptase-polymerase chain reaction (RT-PCR) testing. The patients were divided into the delta variant (n=135) and other variants (n=288) (alpha, beta, gamma) groups, and maternal and perinatal outcomes were compared between the groups. Data including symptoms, laboratory findings, radiological findings, hospital and intensive care unit (ICU) stay, delivery outcomes, and mortality rates were recorded.

Results: The delta variant group demonstrated higher rates of moderate and severe pneumonia than the other variant group (p=0.005). According to the World Health Organization (WHO) classification, 49.6% and 18.5% of patients experienced moderate and severe disease, respectively in the delta variant group, compared to 38.5% and 10.1%, respectively in the other variant group (p=0.001). A total of 20.0% of the patients in the delta variant group and 8.3% of the patients in the other variant group required ICU stay. The length of ICU stay was significantly longer in the delta variant group (p=0.001).

Conclusion: The rates of maternal morbidity and mortality increased in the pregnant population with low rates of vaccination in the period of the fourth wave which was associated with the delta variant. No significant difference was observed in perinatal morbidity between the delta and other variants.

Key words: COVID-19, Delta variant, Maternal morbidity, Perinatal outcomes, Adverse pregnancy outcomes.