Reconsideration of 'purple pushing' urged

OB/GYN News, March 15, 2003 by Sharon Worcester

SARASOTA, FLA. -- Physiology suggests the standard positioning and pushing techniques used during labor and delivery require rethinking, according to Lisa Miller, certified nurse-midwife.

Long Valsalva's maneuvers--or "purple pushing"--and standard supine positioning should be reconsidered, she said at a perinatal symposium sponsored by Symposia Medicus.

Purple pushing--or closed-glottis pushing--during which the patient holds her breath for 10 seconds while pushing, is safe in the approximately 80% of women with low-risk pregnancies. But that doesn't mean it works best. Furthermore, in physiologically high-risk cases, the baby can't tolerate that kind of pushing, said the former labor and delivery nurse-turned-midwife, who is also a lawyer.

In one study of 10 healthy, near-term pregnancies, near-infrared spectroscopy used to evaluate fetal effects revealed that closed glottis and coached pushing efforts led to decreased mean cerebral 02 saturation and increased mean cerebral blood volume. All Apgar scores were below 7 at 1 minute and below 9 at 5 minutes.

Open-glottis pushing, on the other hand, allows the patient to exhale while bearing down and leads to minimal increases in maternal blood pressure and intrathoracic pressure, maintained blood flow, and decreased fetal hypoxia. Long Valsalva pushing can adversely affect maternal hemodynamics, which in turn adversely affects fetal oxygenation, said Ms. Miller, who also is president of Perinatal Risk Management and Education Services in Chicago.

Furthermore, several studies have suggested that in patients who have received epidural anesthesia, delayed pushing is safe and effective for reducing delivery difficulty and decreasing variable decelerations in the fetus.

Pushing in general should be limited to 6-7 seconds, and should be a spontaneous response to a strong urge to push. Coaching of the patient should be limited to encouragement of open-glottis pushing with slight exhalation during pushing, and should only be offered on an as-needed basis, Ms. Miller said. "Sometimes you will have to do [closed-glottis pushing], but that's not my first option," she said.

As for maternal positioning, her mantra is: "I am here to serve my patient-not the other way around," she said, Patient preference is important, but risks must be taken into consideration.

A squatting position will provide the most intrauterine pressure and is safe in low-risk patients. Higher-risk patients, such as those with fetal heart rate changes should avoid this position; in those cases, a side-lying position will improve heart rate patterns and Apgar scores. Other positions to consider include semirecumbency, standing or leaning, and hands-and-knees positioning. Some patients may prefer use of a birthing chair or stool, she noted.

Remember the goals of positioning when helping a patient determine the best position. These include facilitation of alignment of the presenting part to the pelvic axis, encouragement of the mother's efforts toward giving birth, allowing for larger pelvic diameters, improving comfort, and promoting fetal well being, she advised.

RELATED ARTICLE: Remember the Friedman Curve

When a patient reaches 8 cm of dilatation, remember the deceleration phase of the Friedman curve, and avoid starting Pitocin as a reaction to this phase.

At this phase of labor, the patient's body "takes a break" in preparation for the hard work about to come, Ms. Miller said. But this is often misinterpreted as stalled labor, so clinicians often feel they must start Pitocin.

Giving Pitocin at this stage can create fetal hyperstimulation, and can be considered "Munchausen OB," because it is basically creating an emergency in order to respond to it, she explained.

"This is indefensible," she said.