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Cases of two women with COVID-19 who gave birth to a baby who tested positive for the SARS-CoV-2 virus suggested possible intrauterine transmission, but at the Virtual COVID-19 Conference 2020. The Italian scholars who gave the lecture have not yet fully declared it.
“It’s rare, but the evidence that it’s actually possible is accumulating and accumulating,” said Dr Claudio Fenizia, a specialist in immunology at the University of Milan. Still, this should not affect the practices of clinicians-at least not yet, he added.
He said the scientific community needs to rate “the real risk of getting infected during pregnancy. It’s a marginal risk and can have marginal consequences.” Medscape Medical News..
In one of the cases, SARS-CoV-2 was detected in the placenta, vaginal tract, maternal blood of an Italian woman and cord blood of her infant. The virus is Seen before It is rarely found in the placenta, or in maternal blood, or in the female vaginal canal, but in infants who test positive for nasopharyngeal swabs at birth, all are rarely found in the same female.
Examination of pregnant women
Fenizia and his colleagues evaluated 31 women with SARS-CoV-2 who gave birth at three Italian hospitals early in the COVID-19 pandemic. All women were in the final trimester of pregnancy.
“At that time-and I say it was years ago, it’s actually 5 months, not even the length of pregnancy-there was no data on pregnancy,” he said. Explained.
“We have started to collect all possible samples and store them in the best possible way,” he reported. The team came in “to process the placenta and other tissues to store samples in an appropriate manner during the weekends and at night.”
They didn’t know what to do with the sample and knew they had to keep it. “There was a lack of information,” he said.
In addition to storing samples from placenta, maternal blood, umbilical cord blood, vaginal secretions, and the umbilical cord itself, researchers also identified similar inflammation for immunoglobulin (Ig) M and IgG antibodies to SARS-CoV-2. For markers. After birth, each infant was tested for the virus in a nasopharyngeal swab. If positive, the test was repeated.
This is a strength of research, Phenia said.
“In one study, it was not IgM, in another it was placenta,” he explained. “This is a collective report that is a fairly deep analysis of 6 or 7 different sample types from each delivery.”
Researchers included viral RNA results in their studies only if they were able to find the entire genome of the virus and not possible fragments that could not replicate. However, the virus was not cultured to confirm infectivity. This is consistent with many other studies they have found that do not report the ability of the virus to infect cells, he said.
The virus was detected only in two samples of the maternal placenta, and both women had an infant with a nasopharyngeal swab positive at birth.
Distinguish between the two cases
One of those women had severe COVID-19 symptoms and her body was spilled with the virus at birth. SARS-CoV-2 was present in her blood, vaginal swabs, and placenta, and her blood contained both IgM and IgG antibodies. The virus was detected in cord blood and IgG antibody was detected in infant cord blood, but IgM antibody was not detected. Approximately 1 week after birth, infants tested negative for SARS-CoV-2.
Another woman had been sick for a longer period (17 days vs. 6 days), but her symptoms were mild and did not require hospitalization. IgM and IgG antibodies were detected in her own blood and in her infant’s cord blood.
“IgM antibodies are usually not transferred from the placenta, so their presence is the result of direct exposure of the fetus to the virus,” Phenizia said.
Her nasopharyngeal swab was positive for SARS-CoV-2, but the woman had no virus in her blood or vagina at birth. Initially, the researchers classified her placenta negative for SARS-CoV-2, but subsequent testing detected the virus in some placental tissues.
This is interesting, Phenizia explained. If she had a viral surge a few weeks ago, had viremia in her blood, and then had her fetus exposed through the placenta, she and her infant would have had antibodies. Infant nasopharyngeal swabs were positive at birth but negative after 2 days.
The researchers did not have breastfeeding data for either woman.
In only 31 cases, the analysis of data on vertical transmission is limited, “two of the 31 are 6%,” he noted. “I think it’s very rare. I don’t know how rare it is because there aren’t enough to define it, but it’s not even 10%.”
Evaluation of survey results
In contrast, mother-to-child transmission rates HIV Rimmo Fenson, MD, a senior HIV technical adviser at the Elizabeth Glazer Pediatric AIDS Foundation in Washington, DC, said it has been studying for decades whether HIV can pass through the placenta and infect the fetus.
Since the advent of COVID-19, she has been tracking the illness of pregnant women and following case reports of potential vertical transmission. She added that Italian studies add to the literature but are not conclusive.
For one, as much as the medical staff endeavors to keep the delivery room sterile when the baby compresses the intestine in it. Vaginal birth, Feces often come out. In addition, studies have shown that SARS-CoV-2 may be present in feces, which can result in accidental exposure during childbirth.
In addition, unless the amniotic fluid sample also showed the presence of SARS-CoV-2, nasopharyngeal tests were much more likely to identify SARS-CoV-2 in infants at birth than in utero, she said. .. And this study lacked such data because of its completeness.
Moreover, cord blood and placenta SARS-CoV-2 are not definitive evidence of what appears to be an infection.
“In HIV, we didn’t use cord blood because it could be contaminated with maternal blood,” she said. “If you used cord blood, you needed a newborn blood sample for confirmation. As you mentioned with HIV, the placenta may be positive, but not necessarily an infected infant. Placenta is positive That means that maternal viremia has occurred: the placenta, but not necessarily the infant.”
Data on Italian women experiencing severe COVID-19 symptoms make a strong case of vertical transmission, Mofenson said. However, she said she would classify the second woman’s infection as possible “transient contamination”, which resolved at 48 hours at birth.
That doesn’t mean that vertical transparency is a myth. Another example of vertical transmission — report But it’s not yet part of the peer-review process—it’s by far the most definitive if it survives the review.
These researchers discovered SARS-CoV-2 in amniotic fluid, placenta, maternal blood, and neonatal blood. In addition, the infant was intubated and bronchoalveolar lavage was positive for SARS-CoV-2 as a result of the procedure.
However, Moffensson said he agreed with Phenizia that vertical transmission is likely to be rare. Unlike HIV, where the untreated virus warrants the virus in the blood, viremia with SARS-CoV-2 is rare.
“Usually mothers don’t have the virus in their blood,” she said in SARS-CoV-2. Medscape Medical News.. “That’s the first hurdle. If you don’t clear that first hurdle, communication won’t happen.”
Virtual COVID-19 Conference 2020. Truck A11384, announced on July 10, 2020.
