Mating season: How the changing seasons affect human fertility and pregnancy

Pregnancy and birth in fall/winter

Pros

• Sperm count is higher at the beginning of spring and end of fall, but their mobility is better at the beginning of fall. In other words, huddle up on those cold fall evenings;
• With all the layers of clothing you’re wearing, no one will be able to tell that you’ve put on pregnancy weight;
• Because we stay at home more often during the cold times of the year, we spend more time “preparing the nest.”

Cons

• Pregnant women often suffer from a vitamin-D deficiency towards the end of their pregnancy, especially in winter or at the beginning of spring;
• When it’s cold out, no one thinks about exercise, even if it’s necessary to stay in shape during and after pregnancy;
• It takes far more effort to put on boots, a coat, a hat, a scarf… (stops to catch breath)… than to wear sandals. You haven’t gotten around to dressing the baby yet either.

Water retention

Even if there were no direct link between water retention and ambient heat, suffering from it in the middle of a hot, humid summer would make it tough to bear. Eating lots of fruits and veggies is a good way to combat this as many of them have properties that help the passage of urine.

In vitro fertilization

Research has shown that spring is generally the best season for in vitro fertilization (IVF). However, the results remain to be confirmed.

According to a study of 657 Israeli women using IVF for four years, spring was shown to be the most successful season. Fertility would decrease in the summer, however, and reach its lowest rate in fall, before starting a significant incline over winter.

“If these results are confirmed by other studies, seasonal conditions will have to be taken into account and will have an impact on the daily practice of medically assisted procreation,” one of the researchers explained. (From Science et Vie)