Are women fertile for roughly 24 days a year? No, that's misleading: The fertility window for women is approximately four to seven days a month, totaling 48 to 84 days a year, according to medical experts. Ovulation is usually one to two days a month, which is roughly 24 days but that is not the only time a woman is fertile.
The claim appeared as an Instagram post (archived here) on September 5, 2021. It opens:
Women are fertile for roughly 24 days a year. Men are fertile for 365. Want to prevent unwanted pregnancies? You are creating laws for the wrong group.
The Instagram poster, who is not a doctor, provided a misleading statistic. The two days a month, totaling 24 days a year, are for ovulation, not fertility.
According to Very Well Family, the fertility window is much longer than 24 days a year:
Ovulation lasts for 12 to 48 hours, but you are potentially fertile for up to seven days, and maybe up to 10 days, according to the most optimistic studies. This is because sperm can survive up to five days in the female reproductive tract.
The article cites the study titled, "Detection of ovulation, a review of currently available methods":
The fertility window begins approximately 3-5 days (sperm lifespan) before ovulation and continues to a point approximately 1-2 days (oocyte lifespan) after ovulation.
The University of Southern California Fertility reports the fertility window as a "six-day time period":
According to the American Society for Reproductive Medicine (ASRM), the highest pregnancy rates are seen when a couple has intercourse every one to two days during the fertile window. For women whose menstrual cycles are every 28 days, the fertile window is the six-day time period ending with the day of ovulation which is typically around day 15 or 16. When the menstrual cycle is longer or shorter than 28 days, women will ovulate later or earlier.
The message posted appears to be a pushback to the restrictive anti-abortion law passed in Texas, which bans abortions after six weeks. The statistics for male fertility are also misleading as men are not fertile every day for their whole life.
According to the Centers for Disease Control and Prevention, age increases a man's risk of infertility:
Although advanced age plays a much more important role in predicting female infertility, couples in which the male partner is 40 years old or older are more likely to report difficulty conceiving.
