Most babies are born head first.
But a minority are born feet, butt or knees first, which doctors call "breech," from the Middle English word "breeches" for trousers. Doctors have long known that a breech birth increases the odds of complications, but a new study from
If the mother's
These babies are also more likely to die in utero or during their first few months.
"This validates what we suspected, that breech position further complicates problems when the water breaks early," said Dr. Jean Goodman, lead researcher of the study and director of maternal-fetal medicine at
The combination of breech position and early rupture does not increase the chances of bleeding in the brain, though, which is a common cause of death for preemies.
When the baby is positioned head first, Goodman explained, the head blocks most of the fluid loss. The fluid can escape quicker when the baby's feet or butt point toward the birth canal.
"The longer the time between water breaking and birth, the more chances of infection with both head down and breech positions, but more so with breech," she added.
The study evaluated 569 women whose water broke between 24 and 34 weeks' gestation, from 2006 and 2011. Of those babies, 111 were breech.
"Demographics such as income and race don't affect the outcome, but smoking does," said Goodman. "If the mother smokes cigarettes or marijuana, the water is more likely to break early, breech or not."
About 5.5 percent of all births are breech, said the
But the percentage of breech births increases dramatically among premature births, Goodman said, because the babies have not yet prepared for the normal, head-down birthing position.
Breech position is more likely to occur if the mother had a breech birth before. "Some women have an abnormality in the uterus that can make breech more likely," Goodman added.
"Our next study will look at the 'why,'" Goodman said. "Why does the breech position add to these problems?"