COVID vaccine and fertility in women

Pregnant women with COVID-19 are more likely to need intensive care and mechanical ventilation and have a higher risk of death when compared with non-pregnant women. It is plausible that vaccination will reduce these risks.

However, women who are pregnant or at risk of pregnancy are excluded from drug trials including COVID vaccines. Therefore, many drugs after registration are considered to be contraindicated in pregnancy. Despite the lack of information in these randomized trials, useful information can be obtained from animal studies, those who got pregnant in these randomized trials of vaccines and after availability of COVID vaccines.

1. Animal studies
The fertility and miscarriage rates were not affected in over 1000 rats that received the Moderna COVID vaccine before or during gestation.

2. Randomized trials of vaccines
53 pregnancies occurred in the trials of the three vaccines. There was no significant difference in the rate of accidental pregnancies in the vaccinated groups compared with the control groups. This indicates that the vaccines do not prevent pregnancy in humans. Similarly, the miscarriage rates are comparable between the two groups, indicating no detrimental effect of vaccination on early pregnancy.

3. After availability of vaccine
From December 14, 2020, to February 28, 2021, data from the surveillance system were available from 35,691 women who were pregnant at the time of vaccination or after vaccination. Injection-site pain was more frequent among pregnant persons than
among nonpregnant women, whereas headache, myalgia, chills, and fever were
less frequent. 827 women had a completed pregnancy, of which 115 (13.9%) resulted in a pregnancy loss and 712 (86.1%) resulted in a live birth. Adverse neonatal outcomes included preterm birth (in 9.4%) and small size for gestational age (in 3.2%); no neonatal deaths were reported. These were similar to incidences reported in studies involving pregnant women that were conducted before the Covid-19 pandemic.

There was an online claim that antibodies elicited by COVID mRNA vaccines could attack the placenta. A recent small study found similar ongoing pregnancy rate of frozen embryo transfer in women who had anti-SARS-CoV-2 spike IgG following vaccination or natural infection when compared with the control groups.

36 couples resumed IVF treatment 7–85 days after receiving mRNA COVID vaccine. There was no change in semen parameters between two IVF cycles before and after vaccination. No cycles differences were observed in the amount of FSH used, the number and quality of oocytes/embryos obtained before and after receiving mRNA COVID vaccination.

Based on the above information, reproductive age women can receive mRNA vaccination during pregnancy, when planning for pregnancy or undergoing fertility treatment. This will not affect the fertility and pregnant outcomes. There is no need to wait after vaccination if planning for pregnancy or undergoing fertility treatment.

Those undergoing fertility treatment may consider to complete the vaccination before starting the fertility treatment because of common side effects in the few days after vaccination.

Professor Ng