Andrea Johnson was 32 when her first child was born, 33 when the second came along. Eight years later and remarried, she started a second family, having her third child at 41 and discovering just six months later that she was pregnant again.

Ms. Johnson, of Dickerson, MD, is part of a growing trend in the United States for older women to have babies. Between 1990 and 2003, the birth rate for women aged 40 to 44 jumped 58 percent, while the number of births to women aged 45 to 49 grew fourfold (1) The reason? Greater use of assisted reproductive techniques like in vitro fertilization, donor eggs and surrogate mothers–technologies that were still developing 10 years ago but which today have entered the reproductive mainstream.

That’s just one change in the pregnancy/birth picture over the past decade. Today, newer, less invasive tests and greater use of prenatal counseling can help women better assess their risk of giving birth to a child with serious problems; more women are delivering via cesarean section than ever before; and a new specialty–fetal surgery–has evolved to correct certain abnormalities like some types of spina bifida even before babies are born.

“We have become more medicalized, more technologically based,” says Sidney Wu, MD, an attending physician at New York Presbyterian Hospital in Manhattan. “There’s more reliance on electronic fetal monitoring, greater acceptance of epidurals and more genetic testing before the twentieth week of pregnancy.”

Specifically:

* Eighty-five percent of babies born in 2003 were electronically monitored during delivery compared to 68 percent in 1989, even though the risks and benefits of the procedure remain controversial. (1)

* Sixty-seven percent of women with live births had at least one ultrasound during their pregnancy in 2003 compared to 48 percent in 1989. (1)

* About 21 percent of women had their labor induced (artifically started) in 2003, more than twice the number in 1990. At least one study found no medical reason for 25 percent of inductions. (2)

* Nearly 30 percent of all deliveries were cesarean deliveries in 2004–the highest ever reported in the U.S. and a 40 percent increase since 1996. One reason for the increase: fewer vaginal births after an earlier cesarean (VBAC), rates of which dropped 16 percent since 1996. (3)