select search filters
roundups & rapid reactions
before the headlines
Fiona fox's blog

expert reaction to paper on 33 Wuhan babies born to mothers with COVID-19

A paper, published in JAMA Pediatrics, reports on babies born to mothers with COVID-19 in Wuhan.


Dr David Evans, Consultant Neonatologist, Neonatal Intensive Care Unit, North Bristol NHS Trust, and vice-President of the Royal College of Paediatrics and Child Health, said:

“This study highlights the potential for vertical transmission, although post-natal infection after birth has not been excluded in the three COVID-19 positive neonates in this paper.

“The clinical course of two out of the three positive neonates was mild and the third required treatment for other conditions, such as bacterial infection and prematurity, although it is not known whether being COVID-19 positive had a bearing on these conditions.

“The study does illustrate the need to adhere to infection control procedures during the neonatal period, both to protect the infant from acquiring the infection from parents and to protect healthcare staff and other infants for whom they care.”


Dr Pat O’Brien, Consultant Obstetrician and Vice President of the Royal College of Obstetricians and Gynaecologists, said:

“We welcome the findings from this small study of thirty-three babies born during the covid-19 outbreak in Wuhan, China.

“The babies were delivered via caesarean section because the mothers were unwell and had coronavirus-related pneumonia. Of these, three babies tested positive for COVID-19 infection. Reassuringly, the outcomes for these babies were positive.

“It is important to note that this study cannot confirm how the three babies contracted coronavirus and we note that the first test for all three babies was not performed until the second day of life, raising the possibility that infection occurred after birth. The babies were all born by caesarean under strict infection control conditions and were immediately separated from their mothers. However, there is a chance that infection may have occurred in the womb, but this study is not conclusive.

“The conclusions from this study reinforce the need for maternity services to maintain strict infection control measures at the time of birth and closely monitor babies born to women with confirmed or possible coronavirus. 

“The introduction of rapid testing in the coming days and weeks will enable diagnosis of coronavirus in labour.  This will not only enable women who test negative to have a birth experience more in keeping with routine practice, but also enable targeted care for women who have COVID-19 and their babies.

“It is absolutely essential that more data and information is collected. A UK Obstetric Surveillance System (UKOSS) study has now been established to monitor coronavirus infection in pregnancy and birth. The RCOG is receiving daily updates on all UK cases to find out as much information as possible.

“The evidence base for this new virus is growing rapidly. Our clinical team is continually reviewing the latest research, and, as and when new information emerges, we will issue new advice through our guidance.”


Dr Erica Watson, University Lecturer in Reproductive Biology at the University of Cambridge, said:

What the paper describes and concludes

“The study attempts to determine whether the SARS-CoV-2 virus can be transmitted in the womb from mother to baby. The authors find that 3 out of 33 newborns of mothers with COVID-19 also tested positive for COVID-19 and showed symptoms. The other 30 newborns tested negative and did not show symptoms. The authors conclude that they cannot rule out mother-to-fetus transmission.

How were the babies affected?  

“The babies that tested positive for COVID-19 in this study had a fever and pneumonia, symptoms typically associated with this virus. The authors state that all three babies appear to have recovered from their infection. All other babies in the study did not show symptoms and tested negative for COVID-19 even though their mothers tested positive for the virus.

What are the implications for babies born in the UK?  Can COVID-19 be contracted in the womb or is it likely to have been contracted in the hospital after birth? 

“The babies in this study were initially tested two days after birth, during which time they might have come into contact with the virus in the hospital. Several other studies have ruled out transmission of COVID-19 in the womb, including a study that found that umbilical cord blood (the baby’s blood) and amniotic fluid (the fluid that surrounds the baby in the womb) were negative for the virus. Based on the evidence so far, it is unlikely that COVID-19 can be contracted in the womb and so babies are unlikely to be born with the infection. If proper care is taken during delivery, the baby should be safe from infection.

Is there an important message here for women who will give birth during the pandemic? 

“Since the immune system is suppressed during pregnancy, it is important that pregnant women practice social distancing and self-isolation to decrease their risk of COVID-19 infection. If they do contract the virus during pregnancy, the evidence so far suggests that their babies are unlikely to become infected in the womb.”


Dr Elizabeth Whittaker, Consultant in Paediatric Infectious Diseases at St Marys hospital Paddington and member of the RCPCH COVID-19 Expert Advisory Group, said:

“This is the largest case-series of COVID-19 infected mothers to date. Reassuringly, less than 10% of infants were infected, all had mild disease and good outcomes. Although there was radiological evidence of pneumonia in all mothers, the reported symptoms were mild-moderate, none required intensive care admission and all had good outcomes.

“Two of the three infants were born at term and developed mild symptoms which resolved within a couple of days without need for significant medical intervention. The third baby was born prematurely at 31 weeks gestation and despite being positive for Sars-CoV-2, followed the expected clinical course for most infants of that gestation with a good outcome.

“This study is reassuring for pregnant mothers in the UK as the majority of babies were uninfected, and those that were had good outcomes following mild infections.

“There is still no conclusive evidence that COVID-19 is contracted in the womb and it is more likely that the infants were exposed during or immediately after delivery

“This paper provides more reassuring information for pregnant women who will give birth during the pandemic. We would recommend that all pregnant women follow national guidance regarding hand hygiene and self-isolation. For staff caring for these women, isolation and testing of symptomatic women is important to identify those at risk and to ensure close monitoring of neonates at risk of COVID-19.”


Dr Chris Gale, Reader in Neonatal Medicine, Imperial College London, said:

“These results are useful because they add to our understanding of how the coronavirus SARS-CoV-2 affects newborn babies of women with COVID-19. This study is reassuring because it shows that when babies do catch the coronavirus SARS-CoV-2 they have mild disease and recover well. These results are consistent with the small number of previous research reports describing babies infected with the coronavirus SARS-CoV-2.

“This study looked at all the babies born to women who had COVID19 in pregnancy around the time of birth, in a single large hospital in Wuhan, China. The study included 33 women with COVID-19 and the coronavirus SARS-CoV-2 was detected in 3 babies, one of which was born 9 weeks early. The 2 term babies with SARS-CoV-2 had mild signs of disease with good recovery, while the preterm baby had a clinical course in keeping with how premature they were (rather than the virus).

“In all 3 babies that tested positive for the coronavirus SARS-CoV-2 in this study the sample was taken on day 2. This means that we are unable to tell from this study whether these babies were born with the virus (caught it in the womb) or were infected with the virus around the time of birth.  This emphasises the importance of further research in mothers and babies affected by COVID19, like that which is ongoing in the UK and elsewhere.”


Prof Andrew Shennan, Professor of Obstetrics at Kings College London, said:

“Transmission from mother to baby of coronavirus has not previously been observed. Studies have shown that coronavirus has not passed to amniotic fluid, fetal cord blood, placentas or the genital tract of infected mothers. These three cases show the babies are at risk of infection, but given when they are positive (2 days after delivery) this could still be after delivery. We need more evidence to prove transmission from mother to baby can occur in pregnancy. Mothers can be reassured that their babies are usually safe even if the mother is infected.”


Prof Paul Hunter, Professor in Medicine, University of East Anglia (UEA), said:

“The paper by Zeng and colleagues adds to what is a very limited amount of data on the impacts of COVID-19 on new-borns when their mothers have the infection close to delivery. The findings in this paper are consistent with previous studies.  About 10% of babies become infected with COVID-19 but so far there does not appear to be any confirmed reports of adverse outcomes in the baby that I can find. One paper1 did report that one baby from a mother with COVID-19 sadly died but the virus was not detected in any sample from the baby so it is not clear that this was due to COVID-19.

“It is not clear how the babies became infected. All the women in the Zeng paper and most of the women in previous reports gave birth by caesarean section and so were unlikely to have been infected during the birth itself. Given that all the infected babies were first shown to be positive at 2 days, I suspect they were infected after being brought into the world rather than in the womb so this does not change the current consensus that vertical transmission (transmission in the womb) is unlikely. See Royal College of Obstetricians and Gynaecologists advice2

“Current guidance3 from both the Royal College of Obstetricians and Gynaecologists and the Royal College of Paediatrics and Child Health advise that unless there are other issues women with COVID-19 should continue to breast feed their babies and this new evidence should not change this.”


1 (Zhu H, Wang L, Fang C, Peng S, Zhang L, Chang G, Xia S, Zhou W. Clinical analysis of 10 neonates born to mothers with 2019-nCoV pneumonia. Translational Pediatrics. 2020 Feb;9(1):51.)




Prof Ian Jones, Professor of Virology, University of Reading, said:

“This paper reports that, of 33 babies born to Covid-19 positive mothers in Wuhan during the epidemic, 3 were also Covid-19 positive. It is unlikely that these babies were infected in the womb as it is not a general feature of coronavirus infections. While it cannot be completely ruled out it is more likely that infections occurred at or just after birth. All the babies resolved their infection quite quickly and although one was distressed at birth it is likely this was due to other factors. The lessons here are that pregnant women who are hospitalized with severe Covid symptoms need particular attention at the time of birth but that the overall risk to the child is limited.”


Prof Andrew Whitelaw, Emeritus Professor of Neonatal Medicine at the University of Bristol, said:

“This study looks to have been carried out competently and thoroughly.

“Only 3 out of 33 infants born to mothers with confirmed COVID-19 infection had any significant illness. The two born at term had only mild shortness of breath for a few days, did not require mechanical ventilation, and did not receive antibiotics, despite having chest X rays interpreted as pneumonia.

“The only infant who did require intensive care was born at 31 weeks and had evidence of serious bacterial infection in the blood.

“No infant suffered serious illness which could be attributed to COVID-19 as the main cause.

“As all infants had amniotic fluid and umbilical cord blood tested for COVID-19 with negative results, this is evidence against the virus being transmitted from mother to fetus via the placenta. It seems more likely that the 3 infants were infected very soon after delivery, possibly from the mother´s fingers.

“On the basis of this small but much needed study, infants born to mothers with COVID-19 do not appear to be at serious increased risk, over and above the background risks of pregnancy and delivery. However, strict precautions need to be taken to minimize virus transmission to staff and other patients. Conclusions may have to change when larger numbers of infants are reported.”



‘Neonatal Early-Onset Infection With SARS-CoV-2 in 33 Neonates Born to Mothers With COVID-19 in Wuhan, China’ by Lingkong Zeng et al. was published in JAMA Pediatrics at 3pm UK time on Thursday 26 March.


All our previous output on this subject can be seen at this weblink:


Declared interests

None received.

in this section

filter RoundUps by year

search by tag