IQ5: Should mothers infected with Zika during pregnancy breastfeed?


Once again, Zika virus is the focus of this program. In this episode, we’ll explore two more questions: What healthcare providers should do to evaluate infants with positive or inconclusive Zika virus test results, and, should a mother who had Zika virus infection during pregnancy breastfeed her infant.

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Rick Harp: Welcome to Infectious Questions, a public health podcast produced by the National Collaborating Centre for Infectious Diseases. At NCCID. we help those with infectious disease questions connect to those with answers. Hello, I’m Rick Harp.

Shivoan Balakumar: And I’m Shivoan Balakumar. Once again, Zika virus is the focus of this program.

Last episode, our guest expert shared the latest evidence concerning the virus, pregnant women and their partners. She also discussed whether amniocentesis is recommended for recent travellers to Zika endemic areas. It was one of many questions from public health residents in Saskatchewan and in this episode we’ll explore two more.

Harp: We’ll share how to submit your questions later in the show, but first let’s welcome back our expert guest, Dr Vanessa Poliquin, with the Department of Obstetrics and Gynaecology at the University of Manitoba. Doctor, thanks again for joining us on Infectious Questions.

Dr. Vanessa Poliquin: Thank you for having me back.

Harp: Now as we mentioned, this question comes to us from the residents of the public and preventative medicine program at the University of Saskatchewan. What should healthcare providers do to evaluate infants with positive or inconclusive Zika virus test results?

Poliquin: Yeah, that’s a great question, because evaluation of infections around – in and around birth is always challenging. At this time, if any infants are determined to have a positive or an inconclusive Zika test result, really we’re recommending referral to a specialist in paediatric infectious diseases. And that’s because a specialist will be in the best position to liaise with the laboratory in order to interpret the test results, in the context of the clinical picture and to order the appropriate follow-up investigations. So workup in these situations might include blood work, head ultrasound, ophthalmologic examination, hearing evaluations and neurodevelopmental monitoring. Investigations in the infant will also take into account maternal history and clinical context and there could also be further investigations to rule in or out other concomitant diagnoses.

Balakumar: The next question from the public health residents at U of S asks if a mother had Zika virus infection during pregnancy, should she breastfeed her infant? Doctor?

Poliquin: That’s a really tough question right now. Because at this point in time Zika RNA has been detected in breast milk, however there have not been any documented cases of transmission to infants through breastfeeding. And we know there’s a lot of benefits to breastfeeding. So given the current knowledge, for a woman who is infected with Zika virus during pregnancy, the benefits of breastfeeding currently outweigh the potential risk of Zika transmission through breast milk. And unfortunately it seems like a simple and straightforward answer, but there’s still a lot of unknowns with respect to that answer and hopefully further data will be forthcoming.

Harp: Dr Poliquin, would you be aware of the degree to which this question has even been researched?

Poliquin: Well, any reports of transmission would be based on case report only, so we have no case reports of transmission from that mode of transmission, but any organized studies looking at transmissibility I’m not aware of any that are looking at it through… looking at the transmission through breast milk.

Harp: Doctor, last episode you brought us up-to-date on the most significant developments in Zika-related information concerning pregnancy. I’m curious though, what are those still unanswered questions that you’d like to see investigated?

Poliquin: Even just defining the constellation of what Zika infection looks like in terms of a perinatal infection has yet to be defined, defining whether there are particularly vulnerable times during pregnancy, it looks like there can be certain effects throughout all trimesters, but is there a sequence or is there a pattern that exposure at this time during pregnancy leads to this extent of consequences, that’s an ongoing question. And I think that really looking at what’s happening to the children that are born, having been Zika exposed as they move through life is going to be of primary concern. There are some reports that even those infants who are born with normal head circumference, as they move out from birth, their head circumference can drop from normal into lower than normal criteria. So I think that even those infants that are born looking normal, looking to see what happens to them throughout life in terms of their neurodevelopment is going to be very important as well.

For instance, we know with perinatal infection with cytomegalovirus, a proportion of children are born looking very normal but go on to have sensory-neural hearing loss. I think that the world is waiting to see, for those infants that were exposed to Zika, who are born looking normal, what happens to them as they move through childhood, is a question that many perinatal care providers are waiting to know the answer to.

Harp: Dr Poliquin, thank you.

Poliquin: Okay, thank you very much for having me.

Harp: That’s it for this episode of Infectious Questions.

Balakumar: If you have public health questions about Zika virus to share, email them to, or call us toll-free at 1844 847 9698 and record your question there.

Harp: Infectious Questions is a production of the National Collaborating Centre for Infectious Diseases. Production of this podcast has been made possible through a financial contribution from the Public Health Agency of Canada.

Balakumar: Note that the views expressed here do not necessarily represent those of the Agency. The host organization of the NCCID is the University of Manitoba. Learn more at


A public health podcast produced by NCCID, Infectious Questions connects those with infectious disease questions to those who have answers. Subscribe on iTunes, Stitcher and SoundCloud.