- A new study today found that inducing labor for women at 41 weeks may be a safer option than waiting for labor to begin naturally.
- According to a major scientific review of birth records, overdue babies are more likely to be stillborn.
- The researchers estimate that for every 230 women induced at 41 weeks, one infant death could be prevented.
A new trial
According to the National Institutes of Health (NIH), past 42 weeks there’s an increased risk of complications for mother and baby.
The current approach is called expectant management, where doctors take a ‘wait and see’ approach until the mother reaches 42 weeks.
Researchers in Sweden compared induction of labor at 41 weeks with expectant management until 42 weeks in low-risk pregnancies to find out if inducing earlier than 42 weeks reduced adverse outcomes.
Before labor is induced, doctors will examine the patient to determine their cervical score or Bishop Score.
“[We] assess the cervix, its consistency, dilation, [and] position to determine if a cervical ripening agent is needed to soften and thin out or efface the cervix. There are medications that can be given orally or per vagina to accomplish this,” Dr. Kecia Gaither, MPH, FACOG, director of perinatal services at NYC Health + Hospitals/Lincoln told Healthline.
“Once the cervix has been primed, a medication called oxytocin or Pitocin is given to cause contractions.” she said.
Ulla-Britt Wennerholm, associate professor in obstetrics and gynecology, department of obstetrics and gynecology at the Institute of Clinical Sciences, Sahlgrenska Academy, Sweden, told Healthline that previous studies had found inducing labor at term or beyond term could improve “perinatal outcome without an increase in cesarean section.”
“However, most of the included studies are small and performed [a] long time ago,” Wennerholm said.
In the trial, 2,760 women with an uncomplicated, single pregnancy were involved. They were recruited from 14 Swedish hospitals between 2016 and 2018.
Women were randomly assigned to induce labor at 41 weeks or expectant management until they gave birth or were induced at 42 weeks.
Outcomes, such as C-sections and the mother’s health after giving birth, didn’t differ between these groups. However, the trial was stopped early when six infants in the expectant management group died. There were five stillbirths and one early neonatal death.
There were no deaths in the group that was induced. “Although perinatal mortality was a secondary outcome, it was not considered ethical to continue the study,” the authors wrote.
They point out that the study had certain limitations, like differences in hospital policies and practices, which may have affected the results. But the researchers estimate that for every 230 women induced at 41 weeks, one infant death could be prevented.
“Although these results should be interpreted cautiously, induction of labor ought to be offered to women no later than at 41 weeks and could be one (of few) interventions that reduces the rate of stillbirths,” wrote the study authors.
According to the researchers, women with low-risk pregnancies should be informed of the risk profile of induction of labor versus expectant management, and offered induction of labor at no later than 41 full weeks.
“While the study provides informative data to the perinatal literature, it confirms findings that have been known concerning potential outcomes of post dates pregnancies,” said Gaither.
According to a major scientific review of birth records, overdue babies are more likely to be stillborn.
Researchers at Queen Mary University of London analyzed over 15 million pregnancies from countries that include the United States and United Kingdom.
Their findings suggest that pregnancies extending beyond just 37 weeks carry a higher risk of stillbirth. And the risk increases with every week that passes.
However, the scientists behind this study admit the risk is low in absolute terms.
They found the risk for women at 41 weeks pregnant comes out to one additional stillbirth for every 1,449 pregnancies.
“This is the largest study of its kind, and finally provides precise estimates of potential risks of stillbirth. Now that we understand the extent to which stillbirth risks increase with each week of pregnancy, we should be incorporating this information in all discussions around delivery plans in pregnant women at term,” said lead study author Shakila Thangaratinam, PhD, in a statement.
According to the Mayo Clinic, besides stillbirth, the risks of late-term pregnancy include:
- larger than average size at birth
- postmaturity syndrome, characterized by decreased fat levels
- low levels of amniotic fluid that can significantly affect a baby’s heart rate
“If you deliver the baby, the baby will no longer be at risk for a stillbirth,” said Wennerholm. “However, after delivery there is also a risk for the baby to die which may be caused by complications that occur during delivery such as birth asphyxia, infections, or trauma.”
The health problems that the mother can face include serious vaginal tears, postpartum bleeding, and infections.
A recent U.S. study published in the New England Journal of Medicine (NEJM) recommends that women be offered induced labor at 39 weeks.
A new trial adds to previous research finding that birth occurring after the due date can place infants at risk for severe complications, including death.
The mother can also face significant health risks that include bleeding and infections.
Experts say women should be offered the option to induce birth around week 40 of pregnancy.