Birth rates down after vaccine

Rates of Successful Conceptions According to COVID-19 Vaccination Status: Data from the Czech Republic

Birth rates about 30% lower in vaccinated v unvaccinated women

1,300,000 women

Total fertility rate in the Czech Republic

2021, 1.83 births per 1000 women

2022, 1.62 births per 1000 women

2023, 1.45 births per 1000 women

Declining birth rates have been reported in many countries following the COVID-19 pandemic,

and have been linked with economic instability, social inequality, and related social restrictions

Adverse effects of COVID-19 vaccination on human menstrual cycle characteristics have been observed,

but limited data are available on the relationship between vaccination status and birth rates.

We used nationwide data from the Czech Republic

To examine rates of successful conceptions

i.e., conceptions leading to live births 9 months later,

for women,

either vaccinated or unvaccinated against COVID-19,

before successful conceptions

Data from January 2021 to December 2023

Monthly COVID-19 vaccination and birth data for women aged 18-39 years in the Czech Republic

Numbers of SCs per month per 1,000 women,

preconception-vaccinated or unvaccinated women

Pfizer and Moderna mRNA vaccines comprised 96% of all vaccine doses,

Results

1,300,000 women aged 18-39 years in the Czech Republic

The proportion of COVID-19-vaccinated women increased until reaching a steady state of around 70% by the end of 2021.

During the entire study period, SCs per 1,000 women were considerably lower for women who were vaccinated,

compared to those that were unvaccinated.

At the end of June 2021

39% of all women had been vaccinated,

those vaccinated before SC contributed only 7% of all SCs.

Furthermore, SC rates for the vaccinated group were generally much lower than expected based on their proportion of the total population.

Throughout 2022, SC rates remained about 1.5 times higher for women that were unvaccinated before SC compared with those that were vaccinated before SC

Conclusions

In the Czech Republic, SC rates were substantially lower for women vaccinated against COVID-19 before SC than for those who were not vaccinated.

These hypothesis-generating and preliminary results call for further studies of the potential influence of COVID-19 vaccination on human fecundability and fertility.

Unfortunately, the potential influence on reproductive health was not assessed in randomized preauthorization trials of COVID-19 vaccines

The Czech Republic is one of the few countries where nationwide birth data are available for women who were vaccinated or unvaccinated for COVID-19,

It is possible that more women who wished to become pregnant, i.e., achieve SC, chose not to be vaccinated, and/or that more women who did not plan to become pregnant opted for vaccination.

Mechanisms

Vaccination may be associated with menstrual pain and changes in menstrual flow and cycle length

Direct effects of Pfizer on the ovarian follicle were reported recently.