Impact of SARS-CoV-2 Infection on Unvaccinated Pregnant Women: Non-Reassuring Fetal Heart Rate Tracing Because of Placentitis.

In 2020, a new coronavirus, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in China. SARS-CoV-2 infection has been shown to be highly morbid in pregnant women, being a risk factor for several obstetric conditions leading to increased maternal and neonatal mortality. A few studies since 2020 have shown SARS-CoV-2 maternal-fetal transmission and noted placental abnormalities grouped under the term placentitis. We hypothesized that these placental lesions could be responsible for abnormalities in placental exchange and therefore abnormalities in cardiotocographic monitoring, leading to premature fetal extraction. The objective is to identify the clinical, biochemical, and histological determinants associated with the occurrence of non-reassuring fetal heart rate (NRFHR) outside labor in fetuses of SARS-CoV-2-infected mothers. We conducted a retrospective multicenter case series of the natural history of maternal SARS-CoV-2 infections resulting in fetal delivery outside labor due to NRFHR. Collaboration was sought with the maternity hospitals in the CEGORIF, the APHP and Brussels hospitals. The investigators were contacted by e-mail on three successive occasions over a period of one year. Data from 17 mothers and 17 fetuses were analyzed. Most women had a mild SARS-CoV-2 infection; only two women presented severe infection. No woman was vaccinated. We found a substantial proportion of maternal coagulopathy at birth: elevation of APTT ratio (62%), thrombocytopenia (41%) and liver cytolysis (58.3%). Iatrogenic prematurity was noted in 15 of 17 fetuses, and 100% were born by cesarean delivery due to emergency criteria. One male neonate died on the day of birth due to peripartum asphyxia. Three cases of maternal-fetal transmission were recorded following WHO criteria. Placental analysis in 15 cases revealed eight cases of SARS-CoV-2 placentitis, causing placental insufficiency. In total, 100% of the placentas analyzed showed at least one lesion suggestive of placentitis. SARS-CoV-2 maternal infection during pregnancy is likely to generate neonatal morbidity in relation to placental damage resulting in placental insufficiency. This morbidity may be the consequence of induced prematurity as well as acidosis in the most severe situations. Placental damage occurred in unvaccinated women and in women with no identified risk factor, in contrast to severe maternal clinical forms.

Exploring the use of UmbiFlow™ to assess the impact of heat stress on fetoplacental blood flow in field studies (preprint)

Objective To evaluate the impact of heat stress on umbilical artery resistance index (RI) measured by UmbiFlow™ in field settings and the implications for pregnancy outcomes. Methods This feasibility study was conducted in West Kiang, The Gambia, West Africa; a rural area with increasing exposure to extreme heat. We recruited women with singleton fetuses who performed manual tasks (such as farming) during pregnancy. The umbilical artery RI was measured at rest, during and at the end of a typical working shift in women ≥ 28 weeks’ gestation. Adverse pregnancy outcomes (APO) were classified as stillbirth, preterm birth, low birth weight, or small for gestational age, and all other outcomes as normal. Results A total of 40 participants were included; 23 normal births and 17 APO. Umbilical artery RI demonstrated a nonlinear relationship to heat stress, with indication of a potential threshold value for placental insufficiency around 32ºC by universal thermal climate index. Preliminary evidence suggests the fetoplacental circulation response to heat stress differs in APO versus normal outcome. Conclusions The Umbiflow™ device proved to be an effective field method for assessing placental function. Dynamic changes in RI may begin to explain the association between extreme heat and APO. Funding The Wellcome Trust (216336/Z/19/Z) Synopsis Extreme heat exposure is increasing and a low-cost umbilical artery doppler device, UmbiFlow™, can aid understanding of fetoplacental function under heat stress conditions.

Acute Placental Insufficiency Two Weeks After an Asymptomatic COVID-19 Maternal Infection: The Deleterious Effects of The SARS-Cov-2 Placentitis Associated with B.1.617.2 (Delta) Variant. Report of Two Cases. (preprint)

We present two cases of acute severe placental insufficiency in the late second trimester and in the third trimester of pregnancy, emerging within 14 days following a mild COVID-19 (Delta variant) disease in two not vaccinated healthy women with hitherto unremarkable pregnancies. The pathognomonic histopathological findings and the RT-PCR positivity of the placenta suggest the SARS-CoV-2 placentitis as the possible cause of the severe fetal distress. At present, propagation of vaccination and a strict feto-maternal surveillance in the first weeks after maternal infection seem to be the only way to protect the gestation from the risks of acute placental insufficiency associated with the SARS-CoV-2 infection.

Stillbirth after COVID-19 in Unvaccinated Mothers Can Result from SARS-CoV-2 Placentitis, Placental Insufficiency, and Hypoxic Ischemic Fetal Demise, Not Direct Fetal Infection: Potential Role of Maternal Vaccination in Pregnancy.

Stillbirth is a recently recognized complication of COVID-19 in pregnant women. Other congenitally transmitted infections from viruses, bacteria and parasites can cause stillbirth by infecting fetal organs following transplacental transmission of the agent from the maternal bloodstream. However, recent research on pregnant women with COVID-19 having stillbirths indicates that there is another mechanism of stillbirth that can occur in placentas infected with SARS-CoV-2. In these cases, viral infection of the placenta results in SARS-CoV-2 placentitis, a combination of concurrent destructive findings that include increased fibrin deposition which typically reaches the level of massive perivillous fibrin deposition, chronic histiocytic intervillositis and trophoblast necrosis. These three pathological lesions, in some cases together with placental hemorrhage, thrombohematomas and villitis, result in severe and diffuse placental parenchymal destruction. This pathology can involve greater than one-half of the placental volume, averaging 77% in the largest study of 68 cases, effectively rendering the placenta incapable of performing its function of oxygenating the fetus. This destructive placental process can lead to stillbirth and neonatal death via malperfusion and placental insufficiency which is independent of fetal infection. Fetal autopsies show no evidence that direct infection of fetal organs is contributory. Because all mothers examined have been unvaccinated, maternal vaccination may prevent viremia and consequent placental infection.

Acute SARS-CoV-2 alpha variant infection leading to placental insufficiency and fetal distress.

The effect of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Alpha variant (also known as B.1.1.7 lineage, 20I/501Y.V1, the UK variant or VOC 202012/01) infection on pregnancy is currently unknown. We present a case of a 37-year-old woman admitted to our tertiary hospital at a gestational age of 29 weeks and 1 day because of oligohydramnios with reduced fetal movements for 10 days. About 20 days before admission, she tested positive for SARS-CoV-2 Alpha variant. The following day, due to abnormal cardiotocography, increased brain sparing, and absent end-diastolic flow in the umbilical artery, an urgent cesarean section was performed. The neonate had an uneventful admission to the neonatal intensive care unit. All neonatal samples proved negative for SARS-CoV-2. Pathological examination of the placenta revealed intervillous fibrin deposition, ischemic necrosis of villi and histiocytic intervillositis, corresponding with the SARS-CoV-2 placentitis triad. The placental tissue demonstrated a high viral load, possibly explaining the acute onset of placental insufficiently and subsequent fetal distress. This case demonstrates the importance of seeking medical care when experiencing reduced fetal movement in SARS-CoV-2 infected patients since acute infection can induce significant placental and subsequent fetal pathology.

Maternal and fetal effects of COVID-19 virus on a complicated triplet pregnancy: a case report.

BACKGROUND: Coronavirus disease 2019 (COVID-19), the global pandemic that has spread throughout the world, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given the limited scientific evidence on the manifestations and potential impact of this virus on pregnancy, we decided to report this case. CASE PRESENTATION: The patient was a 38 year-old Iranian woman with a triplet pregnancy and a history of primary infertility, as well as hypothyroidism and gestational diabetes. She was hospitalized at 29 weeks and 2 days gestational age due to elevated liver enzymes, and finally, based on a probable diagnosis of gestational cholestasis, she was treated with ursodeoxycholic acid. On the first day of hospitalization, sonography was performed, which showed that biophysical scores and amniotic fluid were normal in all three fetuses, with normal Doppler findings in two fetuses and increased umbilical artery resistance (pulsatility index [PI] > 95%) in one fetus. On day 4 of hospitalization, she developed fever, cough and myalgia, and her COVID-19 test was positive. Despite mild maternal symptoms, exacerbated placental insufficiency occurred in two of the fetuses leading to the rapid development of absent umbilical artery end-diastolic flow. Finally, 6 days later, the patient underwent cesarean section due to rapid exacerbation of placental insufficiency and declining biophysical score in two of the fetuses. Nasopharyngeal swab COVID-19 tests were negative for the first and third babies and positive for the second baby. The first and third babies died 3 and 13 days after birth, respectively, due to collapsed white lung and sepsis. The second baby was discharged in good general condition. The mother was discharged 3 days after cesarean section. She had no fever at the time of discharge and was also in good general condition. CONCLUSIONS: This was a complicated triplet pregnancy, in which, after maternal infection with COVID-19, despite mild maternal symptoms, exacerbated placental insufficiency occurred in two of the fetuses, and the third fetus had a positive COVID-19 test after birth. Therefore, in cases of pregnancy with COVID-19 infection, in addition to managing the mother, it seems that physicians would be wise to also give special attention to the possibility of acute placental insufficiency and subsequent fetal hypoxia, and also the probability of vertical transmission.

COVID-19 during pregnancy should we really worry from vertical transmission or rather from fetal hypoxia and placental insufficiency? A systematic review and meta -analysis (preprint)

Background:COVID-19 is the largest outbreak to strike humanity. The wide scale of fatalities and morbidities lead to a concurrent pandemic of uncertainty in scientific evidence. Conflicting evidences are released on daily basis about the neonatal outcomes of COVID-19 positive mothers.  The aim of this study was to use the relevant case reports and series to determine the percentage of newborns who test positive in COVID-19 positive mothers. Secondary outcomes included examining laboratory and placental abnormalities among fetus-mother pairs.Methods:Systematic review was performed on all studies reporting primary data on fetus-mother pairs with COVID-19. Data bases were searched for studies that met our inclusion and exclusion criteria.Results: Final screening revealed 66 studies, from which the primary data of 1787 mother-infant pairs was obtained. Only 2.8% of mother infant pairs were tested positive, and this finding is identical to percentages reported in former coronaviridae outbreaks. Whereas, 20% manifested with intrauterine hypoxia alongside placental abnormalities suggestive of heavy placental vaso-occlusive involvement. Conclusions: These findings suggest that while vertical transmission is unlikely, there appears to be an underlying risk of placental insufficiency due to the prothrombotic tendency observed in COVID-19 infection. Guidelines for proper prophylactic anticoagulation in COVID positive mothers need to be established.