*** Last updated: November 3, 2020 ***
“These are strange times” is something we’ve been hearing a lot lately. Stranger still when you’re growing a tiny human. My name is Jillian Bardsley and I am family doctor who practices low-risk Obstetrics and delivers at The Ottawa Hospital – General Campus. I decided to write this blog post to help give expectant moms some factual information on their risks with regards to COVID-19, as well as some idea about what to expect about their appointments and time in the hospital.
A research group in England just completed a ‘meta-analysis,’ or intense scientific summary and comparison, of 77 studies on COVID and pregnancy. We now have information on tens of thousands of pregnant women who developed COVID. While our full understanding of COVID in pregnancy and babies continues to evolve, I continue to think that things are overall reassuring.
The rate of COVID in pregnancy is likely somewhere between 7 to 18%; it is likely closer to 7% because this is the rate when ‘universal screening’ or testing everyone is done. Another study has found that approximately 1 in 20 women who show up to labour and delivery have COVID-19, even if they don’t have symptoms. These numbers came from the US and China, where either the government chose not to prepare or didn’t have time to prepare with public health measures. I would be our rate in Ottawa is lower than 7%.
So if you get COVID, will you get sick? How sick?
75% of pregnant women who tested positive for COVID in places doing universal screening had no symptoms at all. That is great news. Compared to non-pregnant women, expectant moms with COVID are actually about 50% less likely to have fever and body aches. This is very interesting as most viruses cause worse symptoms and more severe disease in pregnant women.
Data from New York suggests that 86% of infected pregnant women have only mild symptoms. 9% had severe symptoms, and 5% had very severe symptoms. The general population has rates of 80%, 15% and 5% for mild, severe and very severe COVID infections. Again, this is reassuring.
The large British study that I mentioned earlier did find that globally, compared to non-pregnant women with COVID, pregnant women were more likely be admitted the ICU and to have a breathing tube placed than. They were however, not more likely to die from their COVID infection. Slightly less reassuring, but the rates of these severe infections are generally low. The likelihood of a severe infection increased if the mothers had obesity, high blood pressure or diabetes. These are the same risks for the general population. If you are concerned that you have these risk factors, talk to your prenatal provider about ways to reduce your risk. Maintaining or increasing fitness in pregnancy is a great way to reduce your risk of hypertension, diabetes and excess weight gain. Eat for one, walk for two! Your body and your baby will thank you.
Can COVID affect my baby?
For women early in their pregnancy journey, you do not need to be worried about an increased risk of miscarriage or congenital abnormalities. COVID-19 is somewhat similar to the SARS virus. During that epidemic, we did not see an increased risk of miscarriage or congenital anomalies in women who were infected with SARS. We are expecting this to hold true for COVID-19.
For women later in their pregnancy, getting any bad infection (COVID, the flu, a really bad cold that turns into pneumonia) can increase your risk of pregnancy complications. However, that large British study has given me more good news.
Earlier we thought that the rate of late preterm birth was around 15- 30%. This high number was likely ‘iatrogenic’ or caused by a doctor’s decision. The high percentage came from early pandemic experiences in China where women with COVID were given a C-section to get the baby out ASAP. This was done because the doctors weren’t sure how women in pregnancy would cope with COVID (as written above, we know now that the vast majority of you do very well). When we look at newer data from Western countries, we now see the rate of spontaneous (your body/baby’s decision) preterm birth is actually 6% for women with COVID. Funny enough, the pre-pandemic rate of preterm labour in the US was actually 9.5%. Rates of preterm labour have reduced during in the pandemic- likely because women are getting less sick with other viruses.
The risk of stillbirth or neonatal death is not increased in women who have COVID infections compared with pregnant women who don’t. Phew.
COVID-19 is not present in amniotic fluid nor breast milk. This means that vertical transmission, or the passing of an infection from mother to baby during pregnancy is unlikely. A study out of Wuhan, China has found evidence of an immune response to COVID in babies born to COVID-positive mothers, perhaps suggesting that a small amount of virus is transmitted across the placenta. However, the babies and all maternal fluids (amniotic fluid, vaginal secretions, breast milk) continue to test negative for COVID. Testing done on newborns in New York City also gives us reassurance that there is no vertical transmission. In summary, we do not think that pregnant mothers can transmit COVID to their babies in utero or via breastmilk. There is one report of probable vertical transmission (see last blog post, new as of May 27, Kirtsman et al) in a Torontonian woman with a compromised immune system. The baby tested positive at birth. After a brief support for his blood sugars and temperature, he did very well. I am taking this to mean that vertical transmission is possible, then it is rare. The mother in this care report has evidence of COVID in her breast milk and successfully fed what turned out to be a healthy baby.
With many illnesses, we worry about the effects on the very young and the very old. COVID-19 seems to be different, which children being spared severe disease relative to their adult counterparts. That does not mean that children can’t get sick. It means that very few infected children will get sick enough to cause permanent damage or death. A study that looked at pooled data from multiple other studies confirms that 98% of children with COVID will have mild illness (Chang, et al; see resources as of April 30th). Another pooled study looked at the results of 444 patients under the age of 9 with COVID. There were no deaths in this entire group, and only 1 severe case. (Castagnoli et al.) There is data on 60 pregnant women with COVID-19 and their babies in Wuhan, China. There was only one stillborn baby, born 6 weeks early to a mother with extremely severe COVID. The majority of mothers and babies have done very well. A Wuhan- based study from the week of March 26th reported good outcomes in a group of 7 women and their babies. Only one baby tested positive for COVID within 1 month of birth and recovered very well after a short admission. Data out of New York City also confirms that most mother’s with COVID do well, as do their babies (Breslin, et al). New reassurance from the Canadian Paediatric Society, confirms that children with COVID fare better than their adult counterparts, with the caveat that infants under the age of 12 months, are more likely (around the range of 10%), to have severe disease than children over 12 months.
Most children born to COVID-positive mothers do well but some newborns can get very sick so caution is needed. Red flags in newborns include fever (rectal temperature over 38 degrees Celsius), grunting/moaning, skin near their ribs sucking in when they are breathing and breathing very fast. When you have your baby, ask your nurse to teach you about normal newborn breathing and how to correctly take a temperature. These steps will help you make the judgement call about whether to seek care at CHEO if you think your newborn becomes ill after leaving the hospital.