Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race

The ideal window is before age thirty-five, when fertility is still near its peak; but many women don’t consider the procedure until they’re approaching forty or have even passed that milestone, when the quality of their eggs has already declined.

In couples with recurrent pregnancy loss, the men also had reduced sperm motility and morphology, compared to their peers. As the semen quality goes down, the risk of miscarriages goes up because of bad sperm, which, as you’ve read, are increasingly common.

recent research found that in couples who experience recurrent miscarriages, the men have twice the level of DNA fragmentation in their sperm and four times higher levels of reactive oxygen species in their semen, which can cause DNA damage to sperm, than men whose partners didn’t have a history of repeated miscarriages.

To put this in perspective, consider this: between the ages of twenty-five and thirty-five, women have a 25 to 30 percent chance of getting pregnant with well-timed, unprotected sex in any given month, a 10 percent risk of having a miscarriage, and a 1-in-900 chance of having a baby with Down syndrome; by contrast, women who are forty have a 10 per

women get older, they tend to experience a negative triple whammy, an increase in the risks of three interrelated adverse reproductive outcomes—infertility, miscarriage, and chromosomal abnormalities (including trisomy 21, which is the presence of three copies of chromosome 21, also known as Down syndrome).

The truth is, human reproduction is highly inefficient, especially compared to that of the majority of mammalian species. During a given menstrual cycle, people have—at best, depending on their age—an approximately 30 percent probability of conception with well-timed, unprotected sex.V

(Amazingly, after sexual intercourse, sperm can stay alive in a woman’s reproductive tract for at least five days, especially if they’re protected by fertile cervical mucus. Which means a couple doesn’t need to have unprotected sex on the exact day that a woman ovulates in order to get pregnant; there’s a window of opportunity of approximately thre

identify when she’s on the verge of ovulating, a woman can track several things. First, changes in her cervical mucus: it becomes thin, clear, and slippery like egg white right before ovulation. Or she can monitor her basal body temperature—first thing in the morning, before getting out of bed—because it will rise about half a degree when ovulation

Ovulation occurs around day fourteen in a twenty-eight-day menstrual cycle (day one is the first day of a woman’s period), when a surge in luteinizing hormone (LH) causes one of a woman’s ovaries to release a mature egg.