DALLAS—Texas Gov. Rick Perry is expected to sign a law soon requiring a woman seeking an abortion to have a sonogram and hear a description of the fetus, including whether it has developed fingers, toes or internal organs.

The goal, supporters say, is to improve medical care for women and encourage them to reconsider having abortions.

"We believe that when they see the miracle of life some will change their minds," said Dan Patrick, a Republican state senator who represents part of Houston and who sponsored the legislation, which passed both houses of the state legislature last week.

Abortion-rights supporters say there is no evidence that sonograms, also known as ultrasounds, affect a woman's decision on abortion, and say laws requiring doctors to perform the procedures and describe the results violate patients' rights.

"It discounts women's ability to make health decisions and interferes with the doctor-patient relationship," said Nancy Northup, president of the Center for Reproductive Rights, a New York non-profit that opposes restrictions on legal abortion.