OBG Management: When do you recommend that ObGyns administer the flu vaccine for pregnant women?
Dr. Ault: There are 2 issues to this question: when throughout the year and when during the pregnancy to administer the vaccine. First, you want to give the flu vaccine during the usual influenza season during the fall. As soon as the vaccine is available, you will recommend that pregnant women, even in their late pregnancy, get vaccinated so that their newborns who are 3 and 4 months old in the peak flu season are protected. The patients who deliver over the summer, who are coming in for their postpartum visit during the fall, should be getting vaccinated as well, because they are still vulnerable to influenza and pneumonia for several months postpartum.
If you have patients that come in for preconception visits, you could say: “Let’s get this out of the way. You could be pregnant by the time flu season really gets cranked up.”
Because we see patients 10 or 12 times during pregnancy, we certainly have plenty of opportunities to educate patients about and administer the flu vaccine. There are older data that demonstrate if patients do not get the flu vaccine done during early pregnancy, the opportunity may be lost. It is different now because there is more emphasis on vaccinating all adults. Your patients certainly can get their vaccine at the pharmacy or at their primary care doctor; however, delaying until later pregnancy usually means not getting the vaccine.
I would like to address one recent study from Donahue and colleagues that showed a potentially increased risk of miscarriage with flu vaccination.5 That study was an anomaly, as there are many other studies into the issue. Yes, there are not a lot of first trimester data, but there are other studies, including studies by the same authors, that did not find this to be the case.6-10
The 2017 study by Donahue and colleagues was an anomaly because the group of women they were vaccinating were already at high risk for miscarriage. The women were older, had diabetes, or a history of miscarriages. There is selection bias in the study because the pregnant women who were vaccinated were already at higher risk for miscarriage. The Centers for Disease Control and Prevention and the American College of Obstetricians and Gynecologists are not going to change any of their recommendations based on a single study that is different than our previous data.11