COVID-19 during pregnancy could potentially affect placental function

Objective: COVID-19 is an ongoing pandemic and has been extensively studied. However, the effects of COVID-19 during pregnancy, particularly on placental function, have not been verified. In this study, we used blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to evaluate whether COVID-19 incidence during pregnancy has any lasting effects with respect to placental oxygenation.Methods: This is a case-control study, in which eight cases of singleton pregnancies before 30 weeks gestation with COVID-19 mothers were included. Placental oxygenation was evaluated using BOLD-MRI after 32 weeks of gestation. BOLD-MRI was consecutively performed under normoxia (21% O-2), hyperoxia (100% O-2), and normoxia for 4 min each. Individual placental time-activity curves were evaluated to calculate the peak score (peak +/- R2*) and the time from the start of maternal oxygen administration to the time of peak Delta R2* (time to peak +/- R2*). Eighteen COVID-19-free normal pregnancies from a previous study were used as the control group.Results: No significant differences were found between the two groups regarding maternal background, number of days of delivery, birth weight, and placental weight. The parameter peak +/- R2* was significantly decreased in the COVID-19 group (8 +/- 3 vs. 5 +/- 1, p < .001); however, there was no significant difference in time to peak +/- R2* (458 +/- 74 s vs. 471 +/- 33 s, p = .644).Conclusions: In this study, BOLD-MRI was used to evaluate placental oxygenation during pregnancy in COVID-19-affected patients. COVID-19 during pregnancy decreased placental oxygenation even post-illness, but had no effect on fetal growth; further investigation of the possible effects of COVID-19 on the fetus and mother is warranted.