Natural Induction (labor) - When To Induce

When To Induce

Until recently, the most common practice has been to induce labor by the end of the 42nd week of gestation. This practice is still very common. In the UK, a dating scan is usually conducted around the 12th week of pregnancy to determine the estimated due date. Research suggests that scans done after this date can cause the estimated due date to become less accurate, with the longer time that passes. In the cases of late dating scans, the estimated due date is less accurate which could therefore provoke a woman to be induced unnecessarily. While recent studies have shown a very slightly increased risk of infant mortality for births in 41st and particularly 42nd week of gestation, as well as a slightly higher risk of injury to the mother and child. The recommended date for induction of labor has therefore been moved to the end of the 41st week of gestation in many countries including Sweden and Canada.

Inducing labor before 39 weeks increases the risk of complications and premature death, from factors including underdeveloped lungs, infection due to underdeveloped immune system, problems feeding due to underdeveloped brain, and jaundice from underdeveloped liver. Some hospitals in the United States noticed a significant increase in neonatal intensive care unit patients when women schedule deliveries for convenience, and are taking steps to reduce induction for non-medical reasons.

The odds of having a vaginal delivery after labor induction are assessed by a "Bishop Score". A Bishop Score is done to assess the progression of the cervix prior to an induction. In order to do this, the cervix must be checked to see how much it has effaced, thinned out, and how far open it is. The score goes by a points system depending on five factors. Each factor is scored on a scale between 0-3, any score that adds up to be less than 5 holds a higher risk of delivering by cesarean section.

If an induction causes complications during labor, a Caesarean section is almost always conducted. An induction is most likely to result in successful vaginal delivery when a woman is close to or in the early stages of labor. Signs of impending labor may include softening of the cervix, dilation and increasing frequency or intensity of contractions. The Bishop score may be used to assess the advisability of induction, and is based on such factors.