Maternal and perinatal outcomes in high vs low risk-pregnancies affected by SARS-COV-2 infection (Phase-2): The WAPM (World Association of Perinatal Medicine) working group on COVID-19.

OBJECTIVES: To evaluate maternal and perinatal outcomes in high compared to low-risk pregnancies complicated by SARS-COV-2 infection.

METHODS: This was a multinational retrospective cohort study including women with laboratory-confirmed SARS-COV-2 from 76 centers from 25 different countries in Europe, United States, South America, Asia and Australia from 04 April 2020 till 28 October 2020. The primary outcome was a composite measure of maternal mortality and morbidity including admission to intensive care unit (ICU), use of mechanical ventilation, or death. Secondary outcome was a composite measure of adverse perinatal outcome, including miscarriage, fetal loss, neonatal (NND) and perinatal (PND) death, and admission to neonatal intensive care unit. All these outcomes were assessed in high-risk compared to low-risk pregnancies. Pregnancies were considered as high risk in case of either pre-existing chronic medical conditions pre-existing pregnancy or obstetric disorders occurring in pregnancy. Fisher-test and logistic regression analysis were used to analyze the data.

RESULTS: 887 singleton pregnancies tested positive to SARS-COV-2 at RT-PCR nasal and pharyngeal swab were included in the study. The risk of composite adverse maternal outcome was higher in high compared to low risk-pregnancies with an OR of 1.52 (95% CU 1.03-2.24; p= 0.035). Likewise, women carrying a high risk-pregnancies were also at higher risk of hospital admission (OR: 1.48, 95% CI 1.07-2.04; p= 0.002), presence of severe respiratory symptoms (OR: 2.13, 95% CI .41-3.21; p= 0.001), admission to ICU (OR: 2.63, 95% CI 1.42-4.88) and invasive mechanical ventilation (OR: 2.65, 95% CI 1.19- 5.94; p= .002). When exploring perinatal outcomes, high-risk pregnancies were also at high risk of adverse perinatal outcome with an OR 0f 1.78 (95% CI .15-2.72; p= 0.009). However, such association was mainly due to the higher incidence of miscarriage in high risk compared to low risk pregnancies (5.3% vs 1.6%, p= 0.008), while there was no difference as regard as the other explored outcomes between the two study groups. At logistic regression analysis, maternal age (OR: 1.12, 95% CI 1.02-1.22, p= 0.023) and the presence of a high-risk pregnancies (OR: 4.21, 95% CI 3.90-5.11, p<0.001) were independently associated with adverse maternal outcome.

CONCLUSIONS: High-risk pregnancies complicated by SARS-COV-2 infection are at higher risk of adverse maternal outcome compared to low-risk gestations.