Babies may be at risk of catching the coronavirus from their mother during pregnancy, scientists have warned.
Chinese doctors studied four newborns who tested positive for the infection within a few days of a Caesarean delivery, after experiencing mild tell-tale symptoms.
Three had been isolated as soon as they were born because their mothers had been diagnosed before birth. The fourth mother and baby tested positive a fortnight later.
The researchers said they ‘couldn’t rule out’ that the babies had picked up the virus while still in the womb via the placenta – however, there was no direct evidence of this.
It’s possible the babies contracted the killer virus from the hospital, but the odds were ‘low’ due to special infection control measures in place at the time, the scientists said.
Mothers-to-be are included in the UK Government’s list of vulnerable people who must be protected from the virus.
It’s a precautionary measure because scientists still don’t know if their babies are at risk of infection.
Babies may be at risk of catching the coronavirus from their mother during pregnancy, scientists in China have warned. Pictured, a Thai nurse caring for a newborn wearing a protective face shield to prevent the spread of the coronavirus
The researchers said they ‘couldn’t rule out’ that the babies had picked up the virus while still in the womb via the placenta. The possibility of catching the virus while in hospital was ‘low’ because the babies had been isolated very quickly. Pictured, newborns in Thailand
In the latest study, Dr Zhi-Jiang Zhang and colleagues at Wuhan University studied four babies born via C-section between December 2019 and March 2020.
Three of the mothers were known to have the virus before birth and their babies were separated immediately. Their children presented symptoms while in isolation.
While they can’t be certain, the scientists believe these three babies picked up the virus from their mother.
But the researchers are not so sure when it came to the fourth child because the boy and his mother were not diagnosed until 17 days weeks after his birth.
During that time he was breastfed and came into contact with an infected relative – two scenarios where he could’ve contracted the bug.
|Baby one||Baby two||Baby three||Baby four|
|Age at diagnosis||30 hours||17 days||5 days||5 days|
|Symptoms||Shortness of breath||Fever, cough, vomiting||Fever||No symptoms|
|Setting of disease onset||Hospital||Home||Home||Hospital|
|Isolation at birth||In hospital||No||No||In hospital|
|Hospital stay duration||Not yet discharged||23||30||16|
|Symptoms||Fever||Cough||Fever, cough, loss of appetite||Fever|
|Diagnosis||Before delivery||After delivery||Before delivery||Before delivery|
ARE PREGNANT WOMEN MORE VULNERABLE TO COVID-19 AND WHAT IS THE RISK TO BABIES?
There is no evidence that pregnant women become more severely unwell if they develop coronavirus than the general population.
It is expected the large majority of pregnant women will experience only mild or moderate symptoms because more severe symptoms such as pneumonia appear to be more common in older people, those with weakened immune systems or long-term conditions.
There are no reported deaths of pregnant women from coronavirus at the moment.
If you are pregnant you are more vulnerable to getting infections than a woman who is not pregnant, according to the Royal College of Obstetricians and Gynaecologists.
If you have an underlying condition, such as asthma or diabetes, you may be more unwell if you have coronavirus because is poses a higher risk to those with underlying health conditions.
In terms of risk to the baby, the RCOG says: ‘Emerging evidence suggests that transmission from mother to baby during pregnancy or birth (vertical transmission) is probable.’
But the college emphasised that in all reported cases of newborn babies developing coronavirus very soon after birth, the baby was fine.
There is no evidence right now to suggest an increased risk of miscarriage.
RCOG says: ‘Given current evidence, it is considered unlikely that if you have the virus it would cause problems with the baby’s development, and none have been observed currently.’
Some babies born to women with symptoms of coronavirus in China have been born prematurely. It is unclear whether coronavirus caused this or the doctors made the decision for the baby to be born early because the woman was unwell.
The researchers emphasised they didn’t find ‘direct evidence’ of vertical transmission – there were no traces of the virus being found in amniotic fluid or the umbilical cord blood. But they also didn’t find evidence to dispute it.
Chickenpox, rubella and the herpes simplex virus are examples of infections that can carry over to the foetus and possibly cause harm.
Other than one boy, the babies were not breastfed. Therefore, it’s not possible for them to have caught the virus while drinking their mother’s milk.
The babies may have caught the infection while in hospital shortly after birth, which is known to happen in adult patients.
However, strict infection and prevention controls implemented during delivery make chances of hospital infection low.
The team in Wuhan ruled that babies are significantly more at risk of infection than infants – and this may be due to intrauterine transmission.
Ultimately, ‘intrauterine vertical transmission is possible but direct evidence is still lacking’, the team said.
Lead author Dr Zhi-Jiang Zhang, of Wuhan University, added: ‘COVID-19 is highly contagious and our study suggests that intrauterine transmission [when infection passes across the placenta in the womb] cannot be ruled out, but that the prognosis is good for both pregnant women and newborn babies.’
There are several papers looking into COVID-19 in babies, but more research is needed to to distinguish the risks.
The virus has infected humans for a short time, since December 2019, and so there are many questions over how it could affect a mother during a nine month pregnancy.
The only new mothers who have had the virus during pregnancy were in their third trimester.
The latest study findings are ‘particularly interesting’, according to Dr Shamez Ladhani, paediatric infectious diseases specialist at St George’s, University of London. The hospital is currently recruiting pregnant women with diagnosed COVID-19 for research in the UK.
Dr Ladhani said: ‘Although this study doesn’t provide direct evidence of vertical transmission of coronavirus from mother to baby, it’s difficult to explain how the babies develop the disease so soon after birth.
‘In this case, it’s particularly interesting, as the infants were born by caesarean section and separated from their mother at birth.
‘The good news is that young babies appear to develop mild disease and recover quickly from the infection. However, expectant mothers should continue be mindful of the current measures to prevent spread of the disease to protect both themselves, their babies and those around them.’
Professor Tobias Welte, an infections expert from the European Respiratory Society who was not involved in the study, said: ‘It’s important to protect pregnant women and newborn babies against infection.
‘It’s also important that any cases of Covid-19 in newborns are picked up, monitored and treated quickly and carefully.
‘At this stage we still do not know whether there are any longer-term consequences of infection.’
The findings, published in the European Respiratory Journal, have not been subject to peer-review.
They do support the claims of scientists at Huazhong University of Science and Technology, who also warned intrauterine transmission was possible in a paper published in Jama Paediatrics.
After studying three babies with coronavirus born at Wuhan Children’s Hospital, who each recovered well, they said ‘it is likely’ the virus came from the mother, and not the hospital.
Dr Zeng Lingkong and colleagues said it is ‘crucial’ for mothers to be screened to spot COVID-19 infection.
On the other hand, Dr Chen Huijun and colleagues argued there was ‘currently no evidence for intrauterine infection’ in their paper published in The Lancet.
The team at Wuhan University studied nine pregnant women with COVID-19. Swabs from six of the babies tested negative for the virus, along with amniotic fluid, cord blood, and breastmilk samples.