What happens after a miscarriage? How long do the effects last?

The aftereffects of a miscarriage, defined as the loss of a pregnancy before 20 weeks, depend on how long a woman was pregnant, and, to some extent, how much she wanted a baby.

If a woman misses a period, she may not even know she is pregnant, and miscarriage may be nothing more than an extra-heavy flow, said Dr. Isaac Schiff, chief of obstetrics and gynecology at Massachusetts General Hospital.

''As you go further along, say a miscarriage at 11 or 12 weeks, the bleeding can be quite heavy and the cramps very severe. It's almost like labor," he said.

Hormonally, it can take a few weeks for hormone levels to return to a non-pregnant state, Schiff said. It can also take a week or so for bleeding to stop and several weeks for enlarged breasts to return to normal size.

Psychologically, the loss of a wanted pregnancy can take even longer to heal. Women should ''treat it like a death. Don't trivialize it," said Schiff.

''In addition to feelings of loss, many women feel angry that their bodies aren't 'working' correctly and guilt that they may somehow have caused the miscarriage, so support from family and friends can be especially helpful in letting go of self-blame," Judy Norsigian, executive director of Our Bodies Ourselves, a Boston-based women's health advocacy group, said in an e-mail.

In years past, many women who miscarried had minor surgery, called a D&C, for dilation and curettage, to remove any fetal tissue left in the uterus. A study in August in the New England Journal of Medicine showed that a drug called misoprostol is nearly as effective as a D&C -- 84 percent versus 97 percent in expelling fetal tissue.

JUDY FOREMAN

E-mail health questions to foreman@globe.com.