In 1997, there were 3,880,894 live births in the United States. From 1950 to 1997, the birth rate dropped from 24 live births per 1,000 population to 14.5 per 1,000. Most American women who bear children are between the ages of 20 and 29. However, the proportion of women in their thirties and forties who are having babies has increased throughout this decade. There were 483,220 births to teenage girls in 1997—representing a 16 percent drop since 1991.
Infertility affected 6.1 million women in 1997, up from 4.6 million in 1988—an increase due in part to delayed childbearing and the aging of the baby boom generation. The causes of infertility are equally distributed among conditions affecting the male partner, the female partner, and both partners. Approximately one in four infertile couples are unable to conceive as a result of sexually transmitted diseases, according to the American Society for Reproductive Medicine.
Research has repeatedly indicated that timely and adequate prenatal care greatly enhances the chances for positive pregnancy outcomes. In 1997, more than 82.5 percent of all pregnant women received prenatal care in the first trimester of pregnancy—reflecting a steady improvement since 1970. Still, 3.9 percent of pregnant women received prenatal care only in their third trimester or not at all.
The infant mortality rate reached a new low in 1997 of 7.2 deaths per 1,000 live births. Approximately one-third of that reduction is associated with an estimated 15 percent decline in Sudden Infant Death Syndrome (SIDS) between 1995 and 1996. In spite of these improvements, the infant mortality rate in the United States remains one of the highest in the industrialized world.
The maternal mortality rate has decreased more than tenfold since 1950. In 1997, there were 7.6 maternal deaths per 100,000 live births. However, new, improved data collection techniques suggest that the rate of maternal mortality associated with heart ailments, embolism, hemorrhage, high blood pressure, domestic violence, and infection may be higher than current measures indicate.
Environmental factors contribute substantially to the cause of many diseases in women. Adverse environmental conditions range from water, air, and soil pollution to contamination through the workplace. Occupational hazards include exposure to lead, chemicals, pesticides, tobacco smoke, and continuous noise. Home and community environmental factors—from radon, lead-based paints, electromagnetic fields, food, and cosmetics to heatstroke, hypothermia, and violence—affect women's health. The ways in which environmental factors may disrupt women's endocrine, reproductive, central nervous, and immune systems and cause specific diseases such as cancer, autoimmune diseases, endometriosis, and osteoporosis are only beginning to be understood.