Wait a Minute! I thought Pregnancy was 9 months!
In 2013 ACOG (The American College of Obstetrics and Gynecology) redefined TERM PREGNANCY. For those of us who work in birth and support physiological birth and evidence based medicine this was an incredibly awesome change in obstetrical care.
9 months is a misnomer for the length of pregnancy. Pregnancy has never been exactly 9 months. Rather, most sources say the average pregnancy is about 40 weeks and 3 days. A 2013 study determined the average length of gestation from ovulation to birth is 268 days (38 weeks and 2 days). However, when Doctors determine due dates they are actually looking at the date of your last period, which adds roughly 2 weeks or 14 days. So the 40 weeks 3 days average is pretty good.
40 weeks and 3 days is 9.3 months. However, in the study referenced above they found a normal, natural range of term pregnancy varying 37 days, or five weeks. So you could naturally go into labor at 37 and a half weeks or 42 and a half weeks and that would be within the normal range.
Many care providers get nervous about the baby's health and the health of the mother past that 40 week and three day average. Typical care is to induce by week 41. However, some studies show that:
"Routine labor induction at 41 weeks likely increases labor complications and operative delivery without significantly improving neonatal outcomes."
What the evidence says, and what ACOG recently defined, is that as long as the mother and the baby are healthy (which can be monitored by regular check ups, blood work, and fetal non-stress tests) then proceeding in pregnancy, even past week 41, is safe and healthy for the baby's development. The new definition of Term Pregnancy is:
- Early Term: Between 37 weeks 0 days and 38 weeks 6 days
- Full Term: Between 39 weeks 0 days and 40 weeks 6 days
- Late Term: Between 41 weeks 0 days and 41 weeks 6 days
- Postterm: Between 42 weeks 0 days and beyond