The second I hit save on the manuscript for The Pregnancy Companion, the information began to evolve. Medical and scientific breakthroughs happen on an hourly basis. In additi0n to serving as a community for our readers, this blog serves as my way to help keep the book’s information fresh. This blog post updates the information on pages 167-169 in The Pregnancy Companion book.
Last year I discussed ways that you as a patient can help reduce your c-section risk. A study has recently come out that will hopefully give providers another tool to help safely reduce the c-section rate.
50 years ago, an OB/GYN by the name of Friedman did research on ‘normal labor’ and published his ‘Friedman curve.’ I reference this in the book multiple times as it has been the gold standard for defining normal labor for the last 50 years. The Friedman curve is memorized by every doctor and nurse as they pass through training. His data states that women should dilate 1 cm an hour after 4 cm. If that doesn’t happen, it is considered dysfunctional labor. If no cervical change occurs in 2 hours, then a C-section should be considered. This is a summary, but you get the gist. I have always felt these rules to be stringent. It didn’t take me long in the real world of practice to realize that most women’s bodies do not work that way. Maybe their bodies didn’t read the text book. I would often allow women extra time to dilate and often they did.
Zhang et al recently published an article in Obstetrics & Gynecology (Vol. 116, NO. 6 Dec 2010 p. 1281- 1287) that has blown away Friedman’s work. He looked at labor curves of 62,000 women from 2005-2007. Guess what? Women today do not labor the same as they did 50 years ago.
Currently 30% of pregnant women are obese, the average first mother is older and the average birth weight has steadily increased.
New Flash: Fat Old Women Do Not Labor the Same as Skinny Teenagers!
Wow. We doctors sure are smart.
The key study findings were that current normal labors are much longer than they were 50 years ago:
1. Active labor likely begins at 6 cm instead of 4 cm.
The study showed that it was normal to take 6 hours to progress from 4 to 5 cm and another 3 hours to progress from 5 cm to 6 cm.
After 6 cm, labor usually progresses at 1 cm an hour (not after 4 cm).
2. Average pushing time with an epidural for first baby is 1 hour, with some taking as long as 3.5 hours.
Average pushing time without epidural for first baby was 40 minutes, with some taking as long as 3 hours.
Average pushing time for second baby with epidural was 40 minutes, with some taking as long as 2 hours.
Average pushing time for second baby without epidural was 20 minutes, with some taking as long as 1 hour.
The C-section rate is too high in the US (approaching 30%). This study gives providers the science to back up what many of us have long suspected, that women today dilate slower. As long as mom and baby are healthy, then it is OK to let them continue to labor without doing a preemptive C-section.
How long were you in labor and how long did you push with your baby?