P-074 Evaluation of the impact of SARS-CoV-2 vaccine on semen quality, sex hormones, and pregnancy outcome: a systematic review and meta-analysis

Abstract Study question Does the SARS-CoV-2 vaccine adversely affect semen quality, sex hormones, and pregnancy outcomes? Summary answer The SARS-CoV-2 vaccine affected sperm parameters and hormone levels in men and women but had no significant impact on fertility or pregnancy outcomes. What is known already The available data on the impact of the SARS-CoV-2 vaccine on fertility indices are conflicting; hence this topic remains controversial. Additionally, previous meta-analyses on the effect of the SARS-CoV-2 vaccine on human reproduction evaluated quite a limited number of available studies. Study design, size, duration This study provides a robust systematic review and meta-analysis of the impact of the SARS-CoV-2 vaccine on semen quality, sex hormones, and pregnancy outcomes. This study was registered on PROSPERO (CRD42024533909). Participants/materials, setting, methods The study was performed according to PRISMA guidelines. 5529 studies were collected, employing a pre-defined systematic approach. Upon screening, 44 studies were adjudged eligible for inclusion, these studies were conducted in Iraq (1), Jordan (1), Israel (10), Greece (1), Germany (1), USA (5), China (11), Russia (4), Ukraine (1), Saudi Arabia (1), Indonesia (1), Italy (3), Spain (1), India (1), Turkey (1), and Ireland (1). Main results and the role of chance The SARS-CoV-2 vaccine was associated with a significant increase in sperm concentration, total sperm count, and serum LH in men, these changes persisted after sensitivity analyses. On the other hand, the vaccine markedly reduced progressive sperm motility and circulating testosterone /LH ratio (an index of Leydig cell function), which also remained upon sensitivity analyses. Nonetheless, no significant alteration in ejaculate volume, seminal fluid pH, sperm viability, total motility, the percentage of sperm cells with normal morphology, and sperm DNA fragmentation was observed. Additionally, the SARS-CoV-2 vaccine did not alter serum testosterone, FSH, estrogen, and prolactin. Furthermore, in women, the SARS-CoV-2 vaccine increased AMH and LH levels but decreased FSH and estrogen levels. However, it showed no significant effect on fertilization, implantation, chemical and clinical pregnancy, or live birth rates. Finally, the odds of preterm birth, stillbirth, low birth weight, and very low birth weight were similar between the control and vaccinated groups. Limitations, reasons for caution The eligible studies, being from few countries, may not fully represent the global population. Since SARS-CoV-2 infection is relatively novel and the vaccine was introduced after the pandemic, the included studies evaluated the impact of the vaccine at short-term. Well-designed studies, which investigate the long-term effect of SARS-CoV-2 are necessary. Wider implications of the findings This extensive meta-analysis updates previous findings on the effect of SARS-CoV-2 vaccine on human reproduction. While it alters some hormone levels and semen parameters, it does not impair fertility or pregnancy outcomes. Our findings support vaccine safety, though individuals planning conception should be monitored for potential medical interventions if needed. Trial registration number No