With pregnant women left out of COVID-19 vaccine trials last year, and with some health organizations initially issuing uncertain statements and punting guidance to individual providers, some expecting mothers have been hesitant to get the vaccine.

But obstetricians see no reason to believe the vaccine poses a risk for pregnant women, and more data is coming out showing not only that it is safe, but also that vaccination may confer some benefits to the baby.

Jazmine Kaminski, a labor and delivery nurse at Backus Hospital who is 27 weeks pregnant, said she would've been vaccinated sooner if pregnant women were included in the trials.

She instead opted to wait. After doing more research, talking to doctors, and seeing that vaccinated patients are doing fine, Kaminski now says she will try to get vaccinated before giving birth, though she doesn't have an appointment yet.

As of last week, 69,337 people reported to v-safe — a voluntary health check-in tool from the Centers for Disease Control and Prevention — that they were pregnant when they received the COVID-19 vaccine.

Some also enroll in the pregnancy registry, which involves being contacted once per trimester, after delivery, and when the baby is three months old. The CDC's Advisory Committee on Immunization Practices reported that among the 1,815 people enrolled as of Feb. 19, 275 had completed their pregnancies, including 232 live births.

ACIP noted that miscarriage rates among vaccinated women were in line with background rates of miscarriages among unvaccinated women, and that "no unexpected pregnancy or infant outcomes have been observed related to COVID-19 vaccination during pregnancy."

In late March, the American Journal of Obstetrics & Gynecology published a study finding that the vaccine elicited comparable immune responses in pregnant and non-pregnant women, and that after pregnant women were vaccinated, antibodies were present in umbilical cord blood and breastmilk.

The study enrolled 131 reproductive-age women to get the vaccine, including 84 pregnant, 31 lactating and 16 non-pregnant. No differences were noted in side effects across the groups.

Of the 84 pregnant women enrolled, 13 — all of whom were vaccinated in the third trimester — delivered during the study timeframe. The researchers suggested that transfer of antibodies would be optimized if women were vaccinated earlier but said this needs to be studied further.

The Society for Maternal Fetal Medicine "strongly recommends that pregnant and lactating people have access to the COVID-19 vaccines and that they engage in a discussion about potential benefits and unknown risks with their healthcare providers regarding receipt of the vaccine."

SMFM noted that while risk remains low, reports have shown that pregnancy is associated with a threefold increased risk for intensive care unit admission and 1.7-fold increased risk of death.

Some health organizations take stronger stance than others

Women's Health Connecticut, which includes Shoreline OB GYN in New London and Thameside ObGyn Centre in Groton, is "unequivocally telling women to get vaccinated regardless of the gestational age of their pregnancy," Chief Medical Officer Dr. Mat Saidel said. He said it doesn't matter which vaccine a pregnant woman gets.

He said we "want to make it clear to our pregnant population that the worst thing you can do to your baby is to infect yourself, because you are the container and the shield and the nurturer and the vessel in which this baby is developing, and if you're sick, the baby's going to be sick," he said.

Saidel noted that the science behind the vaccines is not new, and that pregnant women are given other vaccines all the time.

"We recommend that women who are pregnant be the first in line to get flu vaccines, for example, because respiratory viruses are much worse in pregnant women, because their immune system is suppressed," he said. Plus, pregnant women get the Tdap (tetanus, diphtheria and pertussis) vaccine in their third trimester.

He added that after signaling the immune system to produce antibodies, mRNA is broken down rapidly, meaning it "doesn't hang around long enough to cross the placenta." Contrary to some misinformation circulating, the vaccine does not alter DNA, nor does it cause infertility.

Saidel said he can't think of any complication from pregnancy that would cause doctors and nurses at Women's Health to tell people not to get the vaccine.

He said the World Health Organization didn't help with its initial guidance.

In interim recommendations for use of the Pfizer and Moderna vaccines, respectively released Jan. 8 and Jan. 25, WHO said it recommends not to use the vaccine in pregnancy "unless the benefit of vaccinating a pregnant woman outweighs the potential vaccine risks, such as in health care workers at high risk of exposure and pregnant women with comorbidities."

The lack of recommendation was due not to specific concerns but to lack of evidence at the time. WHO said while "pregnant women are at higher risk of severe COVID-19" and the coronavirus is associated with a higher risk of preterm birth, the available data on COVID-19 vaccination in pregnant women "are insufficient to assess vaccine efficacy or vaccine-associated risks in pregnancy."

The organization put out different language on the Moderna vaccine on Jan. 26, saying that "based on what we know about this kind of vaccine, we don't have any specific reason to believe there will be specific risks that would outweigh the benefits of vaccination for pregnant women."

A March 31 article from WHO says there "is no evidence that suggests vaccination would cause harm during pregnancy."

Dr. Stefanie Parks of Coastal Ob Gyn & Midwifery in New London commented, "We have no reason to believe that the vaccine poses any harm during pregnancy, and we give a lot of vaccines during pregnancy, like the Tdap vaccine."

She said OB GYNs are counseling patients that there are real risks to getting COVID-19 while pregnant. She talks to patients about their risk of getting COVID-19 but said it's "ultimately up to the woman to think about what type of risk she wants to undertake."

Parks said she would only recommend against the vaccine if women have had severe allergic reactions to vaccines in the past.

She estimates that 60 or 70% of patients are interested in the vaccine but said that's lower in the first trimester.

Choosing to wait

Michelle Davis, a Pawcatuck resident pregnant with her first child, plans to get vaccinated after giving birth, largely due to timing: She's eight months pregnant. Her age group initially wasn't eligible for vaccination until May 1, less than two weeks before her due date, and she just wanted to focus on giving birth.

Now, her concern would be having the second dose scheduled too close to her due date and having side effects, "because I'm trying to gear up for labor, which I've heard is not a walk in the park."

Jasmine Hinds — who is, like Jazmine Kaminski, a 28-year-old labor and delivery nurse at Backus — said she plans on getting the vaccine when she's no longer pregnant, because it's a newer vaccine that wasn't studied in pregnant women.

She said patients are tested for COVID-19 before coming in, and she thinks she would've more strongly considered getting the vaccine while pregnant if she was working on a COVID unit.

While pregnant women were excluded from initial trials, they are included in current or upcoming studies. Pfizer announced on Feb. 18 that the first participants had been dosed in a global study to evaluate the safety and efficacy of the vaccine in pregnant women.

The trial involves about 4,000 healthy pregnant women vaccinated during 24 to 34 weeks, and monitoring will continue until the infants are about six months old.

Dr. Mathai Mammen, global head of research and development at Johnson & Johnson, said Friday the company is in discussions "to initiate studies in pregnant women and children in the near future."

A local woman is participating in a study involving vaccinated women who are breastfeeding, through the Rebecca Powell Laboratory at the Icahn School of Medicine at Mount Sinai Hospital in New York City. 

New London resident Alison Langeveld had twins last March. She freezes breastmilk at specified intervals after vaccination, and researchers will eventually pick up the samples to assess their antibodies.

As a nurse working on the COVID floor at Lawrence + Memorial Hospital, Langeveld knew she wanted the vaccine regardless, though the lack of data on pregnant or breastfeeding women in the Pfizer and Moderna trials did give her pause.

"You don't know if your kids are getting any benefit or getting any harm from it," she said, "but at the same time, COVID is likely to harm them, and we don't know the aftereffects years down the road."

e.moser@theday.com