mRNA COVID vaccines can protect during pregnancy
mRNA COVID vaccines help protect against severe illness during pregnancy. Large studies have not found increased miscarriage or infertility. Serious side effects are rare. Other vaccine types need their own evidence, and recommendations differ by country.
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Several kinds of evidence support protection
A 2024 review combined 67 studies involving 1.8 million women overall; different outcomes used different subsets. It found protection against COVID complications during pregnancy. mRNA vaccines use a temporary genetic instruction to train an immune response. Historical relative benefits do not give the absolute benefit of a particular current dose.
Conception and miscarriage are different outcomes
The prospective PRESTO cohort found no appreciable reduction in per-cycle conception probability. A Scottish early-pregnancy study found no increased miscarriage odds with the two mRNA products. Selection, comparison groups and missed early losses limit what these observational studies can establish.
The miscarriage denominator matters
A completed registry analysis of 12,097 pregnancies estimated miscarriage risk at 10.79% during weeks 6–20 (95% confidence interval 10.01–11.56), within or below pre-pandemic estimates. Observations were from 2021–2022, published in 2026. It used when pregnancies entered the risk period; the registry was selected and used a historical comparison. The viral 82% calculation removed late-vaccinated live births while leaving ongoing early pregnancies out. Neither that figure nor the original crude completed-pregnancy fraction was a suitable risk estimate.
Infant outcomes need their own evidence
A Nordic study found no association between first-trimester vaccination and major anomalies among liveborn singleton infants. Because it studied live births, it cannot settle early pregnancy loss. National birth rates also reflect social and demographic changes, not just biological fertility.
Safety and side effects
Common reactions and rare serious risks remain product-specific. Temporary menstrual-cycle changes are documented. A Chinese single-center IVF study reported an adverse association after inactivated vaccines, especially near ovarian stimulation; another study did not find a significant adverse association. This is not mRNA evidence or proof of permanent infertility, and it does not establish a waiting period for fertility treatment.
Guidance is local and time-sensitive
Recommendations depend on health, vaccine type and country. Discuss individual eligibility and timing with a clinician who knows your pregnancy and medical history. These findings primarily concern mRNA vaccines, not every platform worldwide.
mRNA COVID vaccines help protect against severe illness during pregnancy.
Keep in mind
- The findings apply to the vaccines, populations and outcomes studied. Personal recommendations depend on your health and current local guidance.
Sources you can check
Publication links open in a new tab, so you can keep your place here.
Effectiveness and safety of COVID-19 vaccines on maternal and perinatal outcomes: a systematic review and meta-analysis (opens in a new tab)
BMJ Global Health, 2024
67 studies and 1,813,947 women overall; outcome-specific samples differ, with searches through January 2023.
Return to reading ↑A Prospective Cohort Study of COVID-19 Vaccination, SARS-CoV-2 Infection, and Fertility (opens in a new tab)
American Journal of Epidemiology, 2022
Prospective US/Canadian pregnancy planners; self-reported exposure and selected participants limit generalization.
Return to reading ↑A population-based matched cohort study of early pregnancy outcomes following COVID-19 vaccination and SARS-CoV-2 infection (opens in a new tab)
Nature Communications, 2022
Scottish miscarriage study; estimates depend on control groups and cannot capture every early loss.
Return to reading ↑Risk of spontaneous abortion after mRNA COVID-19 vaccination received just prior to or during pregnancy: Complete data from CDC COVID-19 vaccine pregnancy registry (opens in a new tab)
Vaccine, 2026
12,097 pregnancies observed in 2021–2022; selected registry and historical comparison, not randomized evidence.
Return to reading ↑Receipt of mRNA Covid-19 Vaccines and Risk of Spontaneous Abortion (opens in a new tab)
New England Journal of Medicine, 2021
Uses a gestational-age-specific risk pool instead of a crude completed-pregnancy fraction.
Return to reading ↑Covid-19 infection and vaccination during first trimester and risk of congenital anomalies: Nordic registry based study (opens in a new tab)
BMJ, 2024
Liveborn singleton infants; cannot answer early-pregnancy-loss questions.
Return to reading ↑COMIRNATY — Prescribing Information (opens in a new tab)
FDA
Product-specific reactions and warnings. Historical trial results in a current label are not all measurements of the current formulation.
Return to reading ↑Timing of Coronavirus Disease 2019 (COVID-19) Vaccination and Effects on Menstrual Cycle Changes (opens in a new tab)
Obstetrics & Gynecology, 2024
Prospective menstrual tracking; cycle changes are distinct from infertility.
Return to reading ↑Associations between inactivated COVID-19 vaccination status and timing and fertility and pregnancy outcomes following frozen-thawed embryo transfer: a prospective cohort study (opens in a new tab)
Frontiers in Endocrinology, 2025
Single-center Chinese IVF study with an adverse association; not mRNA evidence or proof of permanent infertility.
Return to reading ↑Inactivated COVID-19 vaccination does not affect in vitro fertilization outcomes in women (opens in a new tab)
Human Reproduction, 2022
Comparison study did not find a significant adverse association; studies differ in design and treatment timing.
Return to reading ↑Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons (opens in a new tab)
New England Journal of Medicine, 2021
Preliminary registry report with a September 2021 correction; completed pregnancies are not the correct miscarriage-risk denominator.
Return to reading ↑Correction: Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons (opens in a new tab)
New England Journal of Medicine, 2021
Correction to the preliminary registry report.
Return to reading ↑
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These pages have not completed expert review. For personal vaccine advice, talk to a clinician who knows your circumstances.
Research checked: . Wording reviewed: 2026-10-15. Version: vaccine-2026-10-15.
We revisit the page when new evidence or corrections change the answer. A public history of corrections is not available yet.