Pregnancy and the COVID-19 vaccine: what to expect after receiving the shot

Effects of a COVID-19 vaccine on pregnant women An obstetrician-gynecologist answers her pregnant patients' top concerns about getting a COVID-19 vaccine.

MONTREAL — Now that Quebec has opened up vaccine eligibility to pregnant women in the province, obstetrician-gynecologists are working to answer a flurry of questions from patients about safety and side effects.

While some are still hesitant to get a COVID-19 vaccine, Montreal resident Poulami Roychowdhury, now seven months pregnant, made up her mind early on.

“My doctor recommended it but even before she did, I knew I would take it when it was made available, said the McGill University sociology professor.

She made her appointment online Wednesday night, the first day pregnancy was prioritized.

Quebec made its decision about ten days after the Society of Obstetricians and Gynecologists of Canada (SOGC) sounded the alarm about a "daily wave of pregnant women and individuals coming into Ontario ICUs, many requiring ventilators.”

Roychowdhury said she booked her jab for the following week, and “as I was falling asleep, I was feeling really, really happy. I thought, 'Oh, okay, this has been stressing me out!'”

But while much relieved, the academic still had some questions about the possible side effects of the vaccine.

So do the many patients of Dr. Gabrielle Cassir, an obstetrician-gynecologist at St. Mary’s Hospital, specializing in high-risk pregnancies, who offers some guidance below.

NOTE: Pregnant women should speak to their doctors for medical advice.

IS IT SAFE FOR PREGNANT WOMEN TO GET ANY ONE OF THE CURRENTLY AVAILABLE COVID-19 VACCINES?

“The mRNA vaccines like Pfizer and Moderna are the ones recommended in pregnancy given the more robust safety data that’s available,” said Cassir.

However, what matters is having access to a vaccine, and in a timely way, Cassir explained, even though mRNA vaccines are preferred.

ARE THERE ANY CONTRAINDICATIONS ASSOCIATED WITH GETTING THE PFIZER OR MODERNA VACCINES DURING PREGNANCY?

There are no particular constraints for pregnant women, according to Cassir. As with anyone else in the population, if someone has a known allergy to an ingredient of the Pfizer or Moderna vaccines, like polyethylene glycol, they should not receive them, she explained.

Cassir said she is frequently quizzed about the risks of other allergies: eggs, seafood, latex, but says pregnant patients with those allergies are eligible for COVID vaccination.

AT WHAT STAGE OF A PREGNANCY IS IT THE BEST TIME TO GET VACCINATED?

“A patient can get it at any point, at any time irrespective of gestational age,” said Cassir, though it's preferable to get it before the third trimester because that last stage of pregnancy is “a risk factor for more severe COVID-19 infection.”

WHAT HAPPENS IF YOU NEED TO GET OTHER TYPES OF VACCINES AROUND THE SAME TIME?

It’s recommended to wait 14 days after getting a different kind of vaccine, before getting the COVID-19 vaccine, based on limited data, said Cassir.

The opposite situation calls for a different strategy. If a pregnant woman gets a COVID-19 vaccine, “then other vaccines should be delayed by 28 days. One exception being if somebody was post-hepatitis B exposure and needs a [hepatitis B] vaccine,” the specialist said.

There also is no "necessary delay required if a pregnant woman needs to get the WinRho vaccine if she is Rh negative," said Cassir.

WHAT ARE THE POSSIBLE VACCINE SIDE EFFECTS DURING PREGNANCY?

Pain at the injection site is the most frequent complaint so far, and pregnancy-specific complications should not be expected, said the obstetrician-gynecologist.

Cassir said, “on the contrary, tiredness, muscle aches, fever, chills were actually less frequent in pregnant patients in a large U.S. database and that same study managed to show that administration of the vaccine during pregnancy did not increase the risk of miscarriage, preterm birth, malformations or even growth issues in the baby.”

IS A VACCINE SAFE FOR WOMEN WHO ARE BREASTFEEDING?

The COVID-19 vaccine "is recommended for lactating women,” once they’re eligible to receive it in Quebec, Cassir said. In addition to offering protection from disease to the mother, immunity can also be conferred to the newborn through breast milk.

It's not necessary to stop or delay breastfeeding because of vaccination, according to Cassir, a position maintained by the SOGC.

CAN THE VACCINE PRODUCE SIDE EFFECTS IN A BREASTFED INFANT?

Some recent studies have shown that breastfed newborns can develop a fever after their mothers get vaccinated.

One study carried out in Israel ”showed four infants that ended up being diagnosed with a bit of fever but all following a mild course, and most importantly there were no serious adverse effects that occurred in either the mom or the baby,” the specialist said.

MONTREAL RESEARCH ON VACCINES AND PREGNANCY

Since early in the pandemic, the CONCEPTION study based at Ste-Justine Hospital in Montreal has focused on the pandemic’s effects on pregnant women, enrolling about 4,000 participants in the process.

The first phase examined the impact of the health crisis on their mental health and rates of prematurity.

Now the researchers will look at vaccine acceptance, how many pregnant patients end up getting the vaccine, and they'll also gather information about any side effects.

“Now that the government has given the go-ahead we really want to include these women who got the vaccine and some of them who are pregnant and didn’t get the vaccine yet,” said Anick Berard, a perinatal epidemiologist and a professor at the University of Montreal.

So the team is relaunching their recruitment efforts to find as many new pregnant participants as possible.

Those interested in signing up can call the coordinator toll-free at 1-866-220-2654 or send an email to [e-mail].

“Moving forward it’s essential to have local data,” Berard said so that “decisionmakers” in Quebec can base their analyses on how the province's pregnant population has been affected, rather than extrapolating from studies conducted in other countries.