Labor induction is a procedure used to stimulate uterine contractions during pregnancy before labor begins naturally. Inducing labor comes with both risks and benefits to both mothers and babies. Now a new Danish study published in the BJOG: An International Journal of Obstetrics and Gynaecology suggests that proactive labor induction can improve perinatal outcomes among full term pregnancies.
The National Institute for Health and Clinical Excellence (NICE) in the United Kingdom published a guideline on late-term induction in 2008 that recommended induction in weeks 41 and 42 of pregnancy for uncomplicated pregnancies. Danish national guidelines changed the following year to recommend induction during week 41 for uncomplicated pregnancies and even earlier for high-risk pregnancies, with a goal of ensuring birth by 42 weeks.
One danger of labor induction is inducing before 37 weeks, which results in a premature birth. Even with an ultrasound, an estimated due date can be off by as much as two weeks. The March of Dimes recommends delaying induction until at least 39 weeks when possible except for medical reasons. Babies born prematurely often have more health problems at birth and later in life than babies born later.
For the present study, researchers in Denmark sought to assess the changes in perinatal outcomes in children born from 37 weeks of gestation after implementation of a more proactive labor induction practice from 2009.
Using a register-based cohort study, the researchers analyzed data on all births in Denmark from 2000 to 2012 from the Danish National Health Register and the Medical Birth Register. The study encompassed data on a total of 832,935 children born during the thirteen year study period. Of the total children, 770,096 were born after 37 gestational weeks. Of the 770,096 children in the study group, 13.5 percent were born after labor induction, 78.1 percent after planned vaginal delivery, and 8.4 percent after elective caesarean section.
Labor induction from 37 weeks increased from 9.1 percent in 2000 to 26 percent in 2012 in Denmark. Additionally, the percentage of pregnancies in the country that continued beyond 42 weeks decreased from 8 percent in 2000 to 1.5 percent in 2012.
According to the study, the risk of neonatal death decreased from 1.9 to 1.0 neonatal deaths per 1,000 births from 2000 to 2012. The risk of asphyxia decreased by 23 percent from 2003 to 2012, which subsequently decreased the rate of cerebral palsy by 26 percent from 2002 to 2010. The risk of macrosomnia, defined as a birth weight of more than 4,500 grams, decreased by one-third. The risk of peripheral nerve injury decreased by 43 percent.
However, the risk of shoulder dystocia increased by 32 percent.
When the researchers accounted for risk factors such as smoking, increased maternal age, first-time motherhood, multiple pregnancies, and a higher body mass index, the results changed only minimally.
Comments co-author Professor Ojvind Lidegaard from the University of Copenhagen:
“We have seen significant reductions in newborn asphyxia, neonatal mortality, macrosomia and peripheral nerve injuries. Another similar study we conducted recently also demonstrated a halving of stillbirths following the implementation of proactive labour induction practice.
“Our results therefore suggest an overall improvement in perinatal outcomes following a national change towards a proactive management of post-term pregnancy through labour induction.”
Adds John Thorp, BJOG Deputy Editor-in-Chief:
“One quarter of Danish women pregnant beyond 37 weeks now experience labour induction. Labour induction is a simple intervention, but demands a closer surveillance during labour and hospital settings must be able to support such changes.
“These findings require further education and scrutiny before being implemented in other nations.”
The results of the study suggest an overall improvement in perinatal outcomes as a result of a more proactive post-term labor induction practice. However, the researchers caution that the findings must be examined carefully before implementing national initiatives elsewhere.
Perinatal outcomes following an earlier post-term labour induction policy: a historical cohort study: http://onlinelibrary.wiley.com/doi/10.1111/1471-0528.13299/abstract
Proactive labor induction can improve perinatal outcomes, suggests new Danish study: http://www.medicalnewstoday.com/releases/289661.php
Why at least 39 weeks is best for your baby: http://www.marchofdimes.org/pregnancy/why-at-least-39-weeks-is-best-for-your-baby.aspx
Pregnancy Eviction Notice: https://www.flickr.com/photos/woodsfehr/4314560625/