American babies are most likely to be born in August and on Tuesdays, least likely in November and on Sundays. A female is born with 1 million eggs, but only about 300 of the hardiest make it to the final gate, ovulation. About 6,000 women reach menopause every day.
These are a few of the fun facts from the American Congress of Obstetricians and Gynecologists' "2011 Women's Health Stats and Facts," documenting trends in U.S. fertility and reproduction. Some are reason to rejoice. Others, not so.
Only 12 percent of women suffer from infertility. One-third of the time, it is attributed to the woman, one-third to the man, and one-third to a combination or to unknown factors.
Assisted-reproductive therapy, or ART, an infertility treatment, is on the increase, catering to women with an average age of 36, and resulting in more than 600,000 babies a year.
The number of twins is increasing; the number of triplets is on the decline. Both are more likely to occur if mom has assisted-reproductive therapy or is older than 30.
Episiotomies are way down, and forceps deliveries are also down.
Heads-up, parents: The onset of puberty for girls is occurring at younger ages, especially for African-Americans.
Nearly half of high school students have had sex at least once. For 10 percent of the girls, it was involuntary. Note to educators: Kids who have abstinence-only education are no more likely to delay sex or use condoms.
Premature births are more frequent, especially among blacks. Ditto for low birth weights, more so among African-Americans and mothers younger than 15.
One-third of pregnant women gain more weight during pregnancy than their doctors say they should, which is 28 to 40 pounds for women of normal weight.
Only 20 percent of new moms suffer from clinical postpartum depression, but 70 to 85 percent report the "baby blues."
No wonder premenstrual syndrome is the subject of so many jokes; it strikes 85 percent of women. One-third will have at least one urinary tract infection in their lifetimes. The dreaded yeast infection plagues 75 percent of women at least once.
Abortions are down. Each year, 2 percent of women ages 15 to 44 have abortions. Delaware women are most likely to have abortions; Kentucky women least likely.
Half of pregnancies are unintended.
Sixty-two percent of women in childbearing age use contraceptives. The pill is No. 1, followed by sterilization of women, then by sterilization of men.
Women are most likely to have babies in their 20s, but more women in their 30s and 40s are having them. More than 500 older-than-50 women a year have babies.
The induction of labor is up, which could account for the lower number of babies born on Sundays — the doctors' day off.
A cesarean section is the most common surgery among women of reproductive age. New Jersey has the highest C-section rate.
The hysterectomy is the second most common surgery for women of this age. The most common reasons are uterine fibroids for younger women and uterine prolapse or cancer for older women.
Some forms of sexually transmitted diseases are up, while others are down. Chlamydia is the most common, followed by gonorrhea, hepatitis B, herpes and HIV/AIDS.
Although life expectancy has increased, the average menopause age remains 51. Hot flashes affect 75 percent of women during perimenopause, the period before menopause, which lasts for about four years. Estrogen loss after menopause affects everything from skin to sex, so it's no wonder that more than 38 million women are taking hormone therapy.
For every 1,000 live females born, there are 1,048 males. By age 33, though, the ratio is 50-50. By the time we reach age 100, girls rule. Then, it is four women for every man.
6,000 women a day hit menopause
American Congress of Obstetricians and Gynecologists details this, other details about reproduction and fertility
Newborn babies at a maternity ward (Adek Berry/AFP/Getty Images)