Health Watch -- Postponing Labor

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New research may one day help more babies come into the world when they're ready.

Pre-term labor - when the mother goes into labor before the fetus is fully developed and ready for birth - affects nearly half a million infants in the United States each year. These babies face an uphill battle in the first few weeks and potentially later in life as they face developmental delays.

Now researchers at UT Southwestern Medical Center at Dallas may have found a way to postpone labor. This may one day lead to treatments to stop pre-term labor so more infants can be carried to term.

The hormone progesterone keeps the uterus from contracting during pregnancy. Labor occurs when other factors work to keep progesterone from continuing to be effective so that the uterus begins to contract. The researchers set out to find what these other factors are. They discovered that levels of certain proteins that allow progesterone receptors to function decrease dramatically during labor.

They then found that if they gave a drug that causes progesterone receptors to continue to work to pregnant mice in labor, they could delay labor by as much as one to two days. Considering that mice come to full term in about 19 days, that's a significant difference.

Dr. Carole Mendelson, the UT Southwestern researcher who led the study, says that the biochemistry of mice and humans is similar enough that a treatment could be developed based on this research to delay labor in humans.