The phenomenon is not caused by the virus itself but by the need to deliver the baby with a caesarean, thus allowing a better care, even intensive, of the mother.
It can be called a side effect – and not just – of Sars-Cov-2 infection: once the virus is contracted, mothers are in greater real danger of having to give birth to their children long before their natural term (37-41 weeks). It was recorded in the Neonatology of the Federico II Polyclinic in Naples , where 420 babies were born to positive mothers or who developed Covid: five babies needed hospitalization in neonatal intensive care, because they were born at 26, 29 and 33 weeks (here the article
). But not only. It was also discussed in the recent international congress CPC (Covid in Pregnancy and Childhood) Day, organized by Espnic (European Society for Pediatric and Neonatal Intensive Care).
For now we can say that in general the risk of prematurity increases, even if that may mean often mild prematurity (from 34 weeks of gestational age onwards and therefore with relatively mild neonatal problems) e come back severe prematurit (under 28 weeks, which implies far more serious problems), explains the Professor Daniele De Luca, president of Espnic, full professor of Neonatology at the Paris Saclay University and pro-tempore consultant to the World Health Organization.
Very low transmission of the virus from mother to child
Professor De Luca let’s take a step back: is Covid-19 transmitted from mother to child? Yes, although rarely. The set of studies carried out so far shows us that infection from mother to fetus / newborn occurs in 3-4% of cases at most. About half of infants infected with Sars-Cov-2 have no symptoms. The other half have a large percentage of minimal or mild symptoms. Cases of severe neonatal Covid-19 exist but are very rare. How does the infection happen? Generally the “vertical” passage of the virus from mother to child occurs through the placenta, which acts as a lung for the fetus and therefore represents a tissue where the virus finds suitable receptors to enter cells and actively replicate there. We still don’t know exactly why, in a minority of cases, the virus is able to cross the placenta.
Excessive inflammatory reaction
We are studying this theme in our workshops in Paris Saclay and I can anticipate that when the inflammatory reaction of the placenta is particularly sustained this seems to facilitate the passage of the virus into the fetal circulation. It would therefore be a side effect of the excessive placental inflammatory reaction, somewhat like excessive inflammation causes deleterious effects in other organs in patients with severe Covid-19. Because of this WHO has included Sars-Cov-2 in the list of infectious agents transmissible from mother to fetus, such as Toxoplasma or, most recently, the Zika virus. Obviously, these cases of transplacental transmission are much less frequent than those that occur “horizontally”, for the usual route of environmental transmission from the mother or family members to the newborn.
The possible consequences
What are the consequences for the mother? In the recent international congress “CPC (Covid in Pregnancy and Childhood) Day” we were able, at European level, to discuss all the available data. Today we know, that on average, a pregnant woman who contracts Sars-Cov-2 infection has a higher risk of even severe disease than women of the same and non-pregnant. So in general, pregnancy is not a good time to catch Covid-19 at all. And for the baby? For the child they exist two types of risk: that of acquire the infection and develop neonatal Covid-19, which however, as we have seen, extremely low and negligible; is that of be born prematurely which, on the other hand, is not negligible. In fact, due to maternal Covid 19, we are witnessing a significant number of premature births. The latter are mostly iatrogenic in nature, i.e. due to the need to deliver the baby by caesarean section, thus allowing a better assistance, even intensive, for the mother.
A problem with them
But a new problem? No, this is not anything new or a “wave” but a phenomenon that was present since the beginning of the pandemic and that we have learned to recognize by studying Covid-19 mothers and their babies. Preterm birth unfortunately is associated with a whole series of negative consequences that can affect all organs to some extent which are not yet fully developed and especially the lung, brain, intestine or eyes of the baby. The mortality of premature babies and the risk of having sequelae in these organs is inversely proportional to the gestational age at birth: they will be all the more serious the earlier the baby is born.
What do international scientific studies say about it? The data is very clear now, while this effect was not seen in spring 2020 due to the tighter lockdown that had “masked” this effect, protecting mothers from a variety of environmental factors that can contribute to an increased risk of prematurity. With the end of close confinement measures and the advancement of vaccination starting with older people (and women of childbearing age certainly are not), more infections occur in younger people who have not yet been vaccinated and we are observing which is true. effect of Covid-19 in pregnant women, ie on average a more severe form of Covid-19 which may require caesarean section to better assist the patient. Preliminary data from a study we are coordinating at Paris Saclay, but involving various European centers, show that the risk of prematurity is directly proportional to the maternal viral load, that is The more copies of the virus the mother has, the greater the risk of having to have a premature birth with all the negative consequences on the little one. The data are very consistent since it is an effect already described for other consequences of Covid-19, which are all the more serious the higher the patient’s viral load.
Data from the international register
Do positive mothers at Covid end up giving birth earlier? And how much? The very variable average because it depends on various factors, including viral load, but also other variables that determine the severity of the mother’s clinical picture. To understand if some of these are particularly predictive of an extremely preterm gestational age b
idreaming of waiting for enough data and analyzing it. The Epicenter International Registry (here the article
) managed by Espnic has recently closed and will also be able to answer this question. For now we can say that in general the risk of prematurity increases, although this can often mean mild prematurity (from 34 weeks of gestational age onwards and therefore with relatively mild neonatal problems) and sometimes severe prematurity (below 28 weeks, which implies far more serious problems).
Vaccines, unique and powerful weapon
At present, what are the weapons available to mothers to avoid the risk of having a premature birth? Fortunately we have an extremely powerful weapon, vaccination with mRna vaccines. It is of paramount importance that pregnant women, and more generally young women of childbearing age, are vaccinated as soon as possible. This will significantly reduce the risk of developing Covid-19 while also protecting their baby from the risk of premature birth and early miscarriage. The data are evident and clearly demonstrate a very high efficacy of these vaccines. If the mother also becomes infected despite vaccination, we know that it will have a much lower average viral load and that consequently it will not develop Covid-19, or it will develop in a mild form and the risk of prematurity will be much lower just for what I said before.
The contraindications? None
Are there any contraindications to vaccination? Which?
None. The data accumulated first in animal trials, then in randomized clinical trials and finally the clinical data accumulated in “real life” after millions of doses also administered to pregnant women clearly demonstrate that there is no real contraindication. There is no risk for the fetus which, moreover, is not even reached by the injected mRna that is used and then degraded in a short time near the injection site allowing the cells of the immune system to have the correct information to train to recognize and fight Sars -CoV-2 should they ever meet him. On the contrary, the data show that the antibodies produced by vaccination arrive in the mother’s milk and, partially, in the fetal circulation, protecting the baby. Each different thesis is a mere speculation that is not based on anything scientific and not only unsupported by the aforementioned data but not even by basic cell biology knowledge. Because of this i Centers for Disease Control and Prevention in the USA (but also many other international scientific organizations and societies) now recommend vaccination in pregnant women exactly the same way as recommended in any other subject. Because of this a Paris Saclay, that a referral center for high-risk births, pregnant women have been vaccinated for several months now.
August 23, 2021 (change August 23, 2021 | 4:45 pm)