Should you induce a post date pregnancy? And when?
You might be surpised to hear endorsement for an induction from a Doula. But I am the “evidence based doula” and there is a lot of evidence out there that inductions might be a reasonable choice for many women.
The current ACOG recommendations are to not let a pregnancy go past 42 weeks. There is some more recent research coming out though that suggests inductions on or before 41 weeks actually may produce a better prognosis. Why? Chances of infant mortality go up after 41wks0days. There are no significant differences in health of baby or mother when mothers are randomly assigned at 41 weeks to an induction or expectant management of waiting it out, but retrospective studies show that the rates of operative delivery, perineal damage and hemorrhage go up with each week after 40wks0 days. C-section rates remain constant from 38-42 weeks, ie it is not any higher if you induce at term than if you want until 42 weeks. A better predictor of C-section outcome is station of the baby – the more engaged babys head is, the less likely you will have a c-section. Finally, mothers randomly assigned to an induction at 41 weeks report more positive feelings about their birth than those waiting it out in the expectant management group.
So inductions at term don’t seem so evil – they don’t cause higher C-section rates, they don’t cause a higher incidence of mother or infant health problems, and mothers report being happier having a scheduled induction at 41 weeks. At the same time, if you go past 41 weeks infant mortality rates go up, and going past 40 weeks increases your chance each week of operative delivery, perineal tears and hemorrhage
With all of these research studies – I still endorse “natural” induction methods when you can use them. If you are at term and are able to start doing some of the mainstream recommended natural induction techniques (breastpumping, walking, acupressure, membrane sweeping etc) you’re setting yourself up for a better chance of spontaneous labor, or at least a better chance for a successful induction. As usual – all of these issues are worth a good talk with your doctor about the risk and benefit for you as their patient in your choices for your post date pregnancy.
And now the research:
Bruckner et al looked at only one outcome measure – infant mortality. Of course this is such a low risk, but the worst outcome it it happens. They found that chances of mortality go up at a significant rate after 41wks0days. http://www.ajog.org/article/S0002-9378%2808%2900558-9/pdf
Heimstad looked at other measures of health of baby and mother, apgar, operative delivery rate, cesarean rate, umbilical cord pH etc. Moms at 41 weeks were randomly assigned to induction or expectant management (waiting it out) and there were no significant differences in any of the measurable outcomes.
Shin et al showed the that risk of cesarean is not greater for women who undergo inductions at 41 weeks vs. any other week of gestation. What they did observe is that babies that are not engaged in the pelvis at 41 weeks are more likely to result in cesarean – so at 41 weeks the station of your baby is a better predictor of your risk of cesarean. http://www.ajog.org/article/S0002-9378%2803%2900909-8/abstract
Caughey et al show that maternal complications increase after 40 weeks, including higher rate of forceps/vaccum, more perineal tears, and hemorrage. http://www.ajog.org/article/S0002-9378%2806%2901178-1/abstract
Heimstad et al did an interesting study that assessed mothers feelings about their postterm pregnancy courses. At 41 weeks they were randomly assigned to an immediate induction, or fetal monitoring and waiting it out. When asked about their experiences, 74% of the induction group would do another induction, whereas only 38% would choose to wait it out again. http://informahealthcare.com/doi/abs/10.1080/00016340701416929
