Maternal-foetal Transmission of SARS-Cov-2

Overview

One case of maternal-fetal transmission of SARS Cov-2 was published (1). Ig M and Ig G were found at two hours after birth of a new born from a mother COVID-19. Another study on few newborns COVID-19 reported that the SARS-Cov-2 was not transmitted in utero but only after birth. Although there are few data on COVID-19 during pregnancy, according to our national data collections, it appears to be responsible for miscarriages and fetal deaths. There are also intrauterine growth restrictions and an increase of the rate of cesarean sections for maternal indications. Therefore, it is essential to know if there is a maternal viremia which infects the fetus because the consequences in terms of management would be completely different. In fact, the potential intrauterine infection will lead to antenatal monitoring of these patients with an antenatal diagnosis and may be a treatment. Therefore, it seems essential to explore the mode of transmission to the newborn since many newborns have COVID-19 infection The investigators will propose to all pregnant women SARS- Cov-2 positive to perform PCR SARS-Cov-2 tests and /or serology's (IgM and Ig G) on the amniotic fluid, the blood cord and the placenta.

Pregnant women SARS cov-2 positives during pregnancy or during labor tested by a RT-PCR SARS-Cov-2 on nasopharyngeal swabs and/or by serologies. After informed consent the ivestigators will proceed during labor to: 1. A vaginal swab of amniotic fluid during the rupture of the water pocket during labor. 2. a blood sample from the umbilical cord after delivery of the newborn and clamping and sectioning of the cord. PCR Covid-19 and serologies (Ig M and Ig G) as well as investigating viral proteome and cytokines. These are additional samples in addition to the routine samples which have no impact and without risk for the mother the newborn since they are taken after delivery from the side of the placenta after clamping and sectioning of the cord. 3. Samples of 2 fragments of placenta after delivery of the placenta for COVID-19 research, which usually goes to waste or to pathology depending on the clinical context or for infectious tests. In all cases, samples of 3 to 4 cm3 will be taken which will in no way interfere with current analyzes carried out on the placenta which weighs one third of the fetal weight on average. A viral search by COVID-19 PCR will be carried out on the placenta fragment and another part will be frozen for analysis by electron microscopy and study of the viral proteome, cytokines and immune mechanisms. Placenta samples will be frozen at -80 degrees.