Both from the mother or the father

Mar 28, 2008 21:51 GMT  ·  By

About 3-4 % of the human babies are born bottom first. This is the rule in the case of dolphins and whales, as the newborn would drown otherwise, by taking the first breath underwater, but in humans this doubles the risks of complications for the baby (especially of breathing problems at the moment of delivery).

A new study published in the British Medical Journal shows that this type of birth is an inherited trait from either maternal or paternal line. The investigation was made by a team from the University of Bergen (Norway) on 387,000 births, occurred between 1967 to 2004, and revealed that the chance of breech birth doubled if their mother or father was born this way, too.

About 25 % of the human babies are placed in the wrong position at the mid-point of pregnancy, but this percentage plummets to the value of 3-4% at the time of delivery.

The precise cause of the breech position is not understood. By the moment, specialists can only guess that the womb anatomy of the mother is involved. Anyway, many women with breech babies prefer opting for C-sections to avoid complications.

The research team observed that the risk of breech birth increased if both father and mother were born in breech position. The mother may present this risk via inherited anatomical traits, but the risk transmitted from the father should manifest in an anatomical trait of the baby.

"There could be a separate, undetected factor that was increasing the chance of a breech birth in these families. Clinicians should continue to gather information during early prenatal care on maternal and paternal birth presentation and other potential risk factors for breech delivery," said Professor Janet Hardy, from the University of Massachusetts Medical School.

"Having a breech baby does increase the dangers, although, with proper management, the chances are that the baby will be born healthy," Henry Annan, a spokesperson for the Royal College of Obstetricians and Gynecologist, told BBC News.