Concerns regarding the impact of SARS-CoV-2 on reproductive health are understandable given the global scale of the pandemic. Fertility can be affected by multiple factors during an infection, including the direct presence of the virus, systemic inflammation, or secondary effects like fever and stress. Understanding this complexity requires separating the effects of the virus from the body’s general response to illness. Current scientific inquiry focuses on whether any observed changes are transient or indicate lasting damage for those planning families.
Effects of Infection on Male Fertility
The male reproductive system is a potential target for SARS-CoV-2 due to the high expression of the Angiotensin-Converting Enzyme 2 (ACE2) receptor in testicular tissues. ACE2 is the primary entry point for the virus and is found in Sertoli, Leydig, and spermatogonial cells, which regulate sperm production and hormones. This theoretical vulnerability raised initial concerns about direct viral damage to spermatogenesis.
The documented effect on male fertility appears transient, often linked to systemic illness rather than direct viral invasion. Acute infections, especially those accompanied by fever, disrupt the temperature balance required for healthy sperm production. Studies show that men recovering from COVID-19 may experience a short-term reduction in sperm concentration and motility compared to uninfected controls.
This temporary decline typically occurs within 60 to 90 days following infection, aligning with the 70-day cycle required for new sperm maturation. Long-term follow-up suggests these semen quality issues are reversible, with parameters returning to baseline within three to six months post-recovery. For couples trying to conceive, infection in the male partner has been associated with a transient reduction in the per-cycle probability of conception within the first two months.
Effects of Infection on Female Reproductive Function
The impact of SARS-CoV-2 infection on female reproductive function is generally regarded as transient, primarily affecting the menstrual cycle. Many women reported temporary menstrual irregularities following infection, such as changes in cycle length, volume, or flow. These disturbances are attributed to the systemic stress and inflammation caused by the acute illness, which temporarily influences the hormonal axis regulating the menstrual cycle.
Concerns about ovarian reserve, often measured by Anti-Müllerian Hormone (AMH) levels, have been explored, though data is mixed. Some research indicated a reduction in AMH levels and an increase in Follicle-Stimulating Hormone (FSH) following infection, suggesting a temporary decrease in ovarian function. Other studies found that ovarian reserve markers remain similar in women who recovered from COVID-19 compared to uninfected controls. The prevailing evidence suggests that while the inflammatory response may cause short-term fluctuations in reproductive hormones, the long-term integrity of the ovarian reserve does not appear compromised.
COVID-19 and Outcomes in Assisted Reproduction
For couples undergoing Assisted Reproductive Technology (ART) like In Vitro Fertilization (IVF), data regarding past SARS-CoV-2 infection is largely reassuring. Multiple studies found no significant difference in clinical outcomes, such as fertilization rates, oocyte maturity, embryo quality, or overall pregnancy rates, between women with a history of COVID-19 and uninfected controls. The success of an IVF cycle does not appear negatively affected by a previous infection in either partner.
Subtle differences have guided clinical recommendations regarding the timing of procedures. A few studies suggested a potentially higher risk of miscarriage when embryo transfer occurs within 60 days of a female partner’s infection. Consequently, many fertility clinics advise a waiting period, often two months or more, after a documented infection before proceeding with an embryo transfer. The primary negative impact on ART during the pandemic was the high rate of cycle cancellations due to clinic closures or patient illness, not a long-term reduction in treatment efficacy.
Understanding Vaccination and Fertility
Extensive research has consistently shown that COVID-19 vaccination does not impair fertility in either men or women. Studies tracking couples attempting conception found no association between vaccination status and the likelihood of achieving pregnancy. The vaccines, including the mRNA types, teach the immune system to recognize a specific protein from the virus and do not interact with reproductive organs, DNA, or the processes of egg and sperm production.
Data from male partners comparing semen parameters before and after vaccination demonstrate no adverse effects on sperm concentration, motility, or morphology. In women, IVF outcomes, including implantation and embryological results, were similar regardless of vaccination status. The safety profile of the vaccine stands in contrast to the documented risks of contracting the infection, especially during pregnancy, which can lead to severe illness and adverse maternal and fetal outcomes.