Barnafödande faller kraftigt efter massvaccineringen.

Discussion
Based on this population-wide cohort study of nearly 190,000 pregnancies reaching 24 weeks gestation, we found evidence that vaccination up to 12 months before pregnancy was associated with lower risks of extremely and very preterm birth and small-for-gestational age babies for any vaccine type, and lower risks of stillbirth limited to those vaccinated with mRNA vaccine, compared to unvaccinated women. Results were generally consistent for different dose regimens. Higher incidence of maternal venous thromboembolism during pregnancy was observed amongst women who received the viral-vector, but not the mRNA vaccine, compared to unvaccinated women. After accounting for measured confounding factors, the increased risk was estimated to be as low as 10% and as large as a doubling of the risk in the unvaccinated. These results—based on over 50,000 pregnancies pre-conceptionally exposed to at least one vaccine dose—did not differ when stratified by maternal socio-demographic, reproductive and COVID-19 history factors, or in further analyses accounting for missing gestational age, the impact of SARS-CoV-2 infection in pregnancy, or the changing composition over time of the vaccinated vs. unvaccinated groups as the vaccination program was rolled-out. Our findings are novel, as there is no comprehensive and large-scale evidence on the association of COVID-19 vaccination with mRNA and viral-vector vaccines before pregnancy and birth outcomes.

Results
Out of 1406 studies screened, 29 were included in the systematic review. These studies, conducted in Israel (34.5 %), USA (24.1 %), Russia (20.7 %) China (10.3 %), Italy (3.5 %), North America (3.5%) and Turkey (3.5 %) were of poor (34.5 %), moderate (58.6 %) and good (6.9 %) quality. Meta-analyses were performed for pre- and post-vaccination sperm progressive motility (44 %, 95 % CI 42 %-62 % vs 43 %, 95 % CI 31 %-59 % p = 0.07) and concentration (50.6 mln/ml, 95 % CI 35.1–72.8 vs 55.4 mln/ml, 95 % CI 37.4–82.2p = 0.12). Biochemical (0.51, 95 % CI 0.40–0.66 vs 0.60, 95 % CI 0.53–0.68p = 0.45) and clinical (0.45, 95 % CI 0.37–0.54 vs 0.47, 95 % CI 0.40–0.55 p = 0.31) pregnancy rate did not differ among vaccinated and not vaccinated groups. Subgroup meta-analyses based on the type of vaccine showed no significant difference: between vaccinated with mRNA vaccines and non-vaccinated regarding biochemical pregnancy rates; pre- and post-vaccination with Gam-COVID-Vac regarding testosterone, FSH and LH levels; pre- and post-vaccination with BNT162b2 vaccines regarding sperm volumes.

Conclusion
Based on the studies published so far, there is no scientific proof of any association between COVID-19 vaccines and fertility impairment in men or women.

All included studies found a higher percentage of at least one menstrual disorder in the first cycle after different types of COVID-19 vaccination and after different doses. All included cohort studies found a positive association between COVID-19 vaccines and one or more menstrual disorders. These studies also mentioned that these disturbances were transient. Overall, menstrual disorders were predominantly mild and in most cases the menstrual cycle returned to normal within several months or by the time the second dose was given (Alahmadi et al., 2022; Edelman et al., 2022b; Farland et al., 2022; Gibson et al., 2022; Laganà et al., 2022; Rogers et al., 2022; Taşkaldıran et al., 2022; Wang et al., 2022; Woon and Male, 2022; Alvergne et al., 2023a; Al-Furaydi et al., 2023; Darney et al., 2023; Trogstad et al., 2023; Wesselink et al., 2023).

All included studies found a higher percentage of at least one menstrual disorder in the first cycle after different types of COVID-19 vaccination and after different doses. All included cohort studies found a positive association between COVID-19 vaccines and one or more menstrual disorders. These studies also mentioned that these disturbances were transient. Overall, menstrual disorders were predominantly mild and in most cases the menstrual cycle returned to normal within several months or by the time the second dose was given (Alahmadi et al., 2022; Edelman et al., 2022b; Farland et al., 2022; Gibson et al., 2022; Laganà et al., 2022; Rogers et al., 2022; Taşkaldıran et al., 2022; Wang et al., 2022; Woon and Male, 2022; Alvergne et al., 2023a; Al-Furaydi et al., 2023; Darney et al., 2023; Trogstad et al., 2023; Wesselink et al., 2023).