According to results from four current clinical
trials, vaccination with the ChAdOx1 nCoV-19 vaccine has no effect on
fertility, miscarriage, or other birth outcomes in women who were vaccinated
before pregnancy, adding to the body of information on the safety of COVID-19
vaccine in these women.
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"Fears of COVID-19 vaccination having negative
effects on fertility have hampered vaccine adoption in some communities,"
the Oxford COVID Vaccine Trial Group researchers explained.
"Vaccine reluctance during pregnancy or among
women of reproductive age could have significant public health
implications," they explained, "since infection with SARS-CoV-2
during pregnancy is a risk factor for severe maternal disease and
sequelae."
The current study looked at pregnancies that occurred
in four ongoing ChAdOx1 nCoV-19 (AZD1222) clinical trials in three countries:
the United Kingdom, Brazil, and South Africa. Women of reproductive age
(specified as 49 years) were randomized to receive either the ChAdOx1 nCoV-19
vaccine or a placebo vaccine in the experiments. These women were not supposed
to be expecting a child when they enrolled in the study. Women who became
pregnant after being vaccinated were tracked for three months after their
babies were born.
121 out of 9,755 participants (about 1%) became
pregnant throughout the research.
Overall, the researchers found no link between the
ChAdOx1 nCoV-19 vaccine and decreased fertility (rates, 0.0102 versus 0.0089;
rate ratio [RR], 1.14; p=0.53). When the study was confined to include women
with viable pregnancies, the results were similar (rate, 0.0065 versus 0.0060;
RR, 1.08; p=0.80).
With ChAdOx1 nCoV-19 vs control, there was also no
increased risk of miscarriage (defined as loss of pregnancy before 23 weeks of
gestation; RR, 0.67; p=0.51).
According to the researchers, 15 livebirths had
occurred by the time of analysis, three of which were preterm births in the
ChAdOx1 nCoV-19 group, though they were all in the late preterm stage (34 to 37
weeks of gestation).
In fact, neither group experienced any stillbirths or
neonatal deaths.
"Vaccination with ChAdOx1 nCoV-19 had no effect
on fertility," the researchers concluded. "In global clinical trials
with ChAdOx1 nCoV-19, there was no increased risk of miscarriage and no cases
of stillbirth in women vaccinated before pregnancy."
"With the growing availability of misinformation,
which continues to effect vaccine uptake," they wrote, "our results,
combined with published data on mRNA vaccines, can provide evidence to guide
women in making vaccination decisions."
Source: [Lancet 2021;doi:10.1016/S0140-6736(21)02282-0]