Pregnancy is considered a special immunological situation. During pregnancy, the maternal immune system is supposed to establish and maintain tolerance to the fetus which is considered an allogeneic graft, while it must preserve the ability to protect against pathogens. Therefore, systemic and local immune responses must be finely regulated during pregnancy.5. Changes in immune responses during pregnancy could make pregnant women susceptible to COVID-195 and lead to perinatal and maternal complications. In the present study, we investigated these complications in a large cohort of pregnant women with COVID-19. Overall, clinical manifestations of COVID-19 were not different between our cohort of pregnant women and previously reported cases.4. Among the women evaluated, 22 women had to be admitted to intensive care and 30 premature deliveries occurred. However, there was no significant difference in the rate of prematurity between women admitted to intensive care and the other group of pregnant women. There were significant associations between ICU admission and many parameters such as presence of dyspnea, COVID-19 related CT scan results, need for a ventilator and low O2 saturation – all of which indicate the plight of patients. In accordance with the difference between the therapeutic protocols for patients admitted to intensive care and those treated in general departments, admission to intensive care was associated with the administration of antivirals, corticosteroids and heparin treatments.
Notably, the cause of delivery was significantly different between the two groups, with preterm labor pain and fetal distress being the most common cause of delivery in non-hospitalized and ICU admitted patients, respectively. This could indicate the impact of a critical situation of the pregnant woman on fetal distress. Additionally, we reported that route of delivery, neonatal death and asphyxia, Apgar score, and gestational age at delivery were associated with ICU admission. However, the rate of IUGR was lower in the non-ICU population. This could be due to better maternal health conditions in women not admitted to ICU compared to those admitted to ICU.
The observed association between ICU admission and delivery route is consistent with the previously reported need for emergency caesarean sections as a complication of pregnancy in women with COVID-1911SEA12and SARS infections13. According to a recent meta-analysis, symptomatic COVID-19 was associated with a higher possibility of caesarean section and preterm delivery compared to asymptomatic infection.ten.
The frequency of preterm labor in our patient cohort was significantly lower than the previously reported rate of 42%14. A population-based cohort study has suggested an association between COVID-19 in late pregnancy and a higher risk of iatrogenic preterm birth15.
In the present study, significant associations were also observed between prematurity and variables such as positive PCR results, the need for a ventilator, the absence of enoxaparin sodium administration, the administration of heparin, diabetes, preeclampsia, route of administration, platelet count and creatinine level. These observations indicate a possible link between prematurity and maternal health complications. Moreover, many parameters such as diabetes and preeclampsia could affect perinatal complications in women with COVID-19.
Regarding adverse neonatal outcomes, ICU admission was associated with low Apgar score and neonatal admission to the ICU neonatal ward (NICU). A systematic review of clinical outcomes of 211 PCR-confirmed and 84 clinically diagnosed cases of pregnant women with COVID‐19 reported nearly one-third of neonates admitted to NICU16. Yet, in our patient cohort, 31 cases were admitted to NICU.
In our cohort of patients, asphyxia occurred in two cases; both were born to pregnant women admitted to intensive care. This observation could also imply the impact of a critical situation of the mother on the newborn. Among 40 PCR tests performed on neonatal throat samples, 11 tests came back positive, indicating the possible transmission of SARS-CoV-2. Consistent with our finding, Zeng et al. reported three positive SARS-CoV-2 cases among 33 neonates born to women affected by COVID-1917. Although environmental contamination cannot be excluded, similar to the study conducted in China17, the maternal origin is mostly supported thanks to strict prevention measures. A systematic review of the literature indicated a 3.2% rate of vertical transmission of SARS-CoV-218.
As expected, significant associations were also observed between prematurity and IUGR, NICU admission, and neonatal weight.
The data presented above show that neonatal outcomes are different in this cohort of pregnant women infected with COVID-19. Observed differences in neonatal outcomes could be explained by complex immune responses, differences in gestational age, and duration and severity of COVID-19 infection, necessitating individualized approaches for treating these women.
Taken together, in the present study, we reported the association between numerous clinical variables and perinatal outcomes in pregnant women with COVID-19. The main strength of the present study is the inclusion of a large sample of cases that is comparable to published systematic reviews in this area.