Delayed pushing doesn't increase fetal trauma. (Second-Stage Labor).

SARASOTA, FLA. -- Delaying pushing until the mother experiences Ferguson's reflex can minimize her fatigue and does not increase the likelihood of fetal trauma during second-stage labor.

"We should try to take advantage of natural physiologic function as much as possible during birth," said Ellen Kopel Zottoli, R.N., of Sarasota Memorial Hospital. Many women experience a latent resting period near the time of complete dilation that is characterized by a decrease in uterine activity. This usually lasts about 20 minutes and is a time when the mother can rest and collect herself before beginning to actively bear down, Ms. Zottoli said at a symposium on high-risk pregnancy sponsored by Symposia Medicus.

Then, when the fetal head descends past the ischial spines (+1 station), the mother feels the sudden strong urge to bear down. This is Ferguson's reflex, and it typically is accompanied by a loud maternal groan.

If women are permitted to wait until they experience this response to the pressure of the fetal head stretching the musculature and stimulating the nerve receptors in the pelvic floor, they are less likely to be exhausted by the birth. This has important implications for subsequent bonding with the baby and breast-feeding.

Delaying pushing also has little effect on duration of labor. In a study of patients who had an epidural during delivery, one group of patients was instructed to start pushing the minute they reached 10 cm of cervical dilation, she said.

Patients in the other group were asked to not push for 1 hour unless they felt the urge to do so. "The patients who were not asked to push only delivered 8 minutes later than the others.

"If I were a mom trying to push my baby out, I'd be pretty glad I didn't push for those 52 minutes," she said.