THURSDAY, Feb. 10 (HealthDay News) -- If women are given control of the amount of epidural anesthesia they get during labor and delivery, they use about 30 percent less medication than when given a standard dose from a doctor, a new study shows.

"We looked at patient-controlled epidural anesthesia, and found the women were basically as comfortable as women on a continuous dose, and there was a 30 percent reduction in the amount of anesthesia used," said study author Dr. Michael Haydon, a perinatologist at Long Beach Memorial Medical Center in California.

Haydon is scheduled to present the findings Thursday at the Society for Maternal-Fetal Medicine annual meeting in San Francisco. Research presented at meetings is generally preliminary, experts note, since it has not been subjected to the same rigorous scrutiny as research published in peer-reviewed medical journals.

Epidural anesthesia is a common form of localized pain relief used during childbirth, according to the American Congress of Obstetricians and Gynecologists. A small catheter is inserted into the epidural space in the spine by an anesthesiologist, and a painkiller is then given to numb the area.

There is a low risk of side effects with "epidurals," but these can include nausea, backache, a sudden drop in blood pressure, severe headache and more difficulty pushing (possibly resulting in the need for forceps or a Cesarean delivery), according to the American Pregnancy Association.

Generally, epidural anesthesia is given on a continuous basis, according to Haydon. But patient-controlled devices that can control delivery of the anesthesia are widely available, he added. Patients are given a button to push when they feel they need more medication. The devices are programmed to only provide a specific amount of medication for specific time periods to ensure that people don't give themselves too much.

For the current study, Haydon and his colleagues recruited 270 women who were pregnant for the first time. They were randomly selected for one of three groups: the standard dose given as a continuous infusion; a continuous infusion with an additional patient-controlled option; and patient-controlled anesthesia only.

Women in all three groups received an initial injection of 2 milligrams (mg) of bupivicaine/20 micrograms (mcg) of fentanyl, followed by a maintenance epidermal infusion of 0.1 percent bupivicaine/2 mcg/ml fentanyl.

The first group used an average of 74.9 mg of anesthesia during labor. The second group used an average of 95.9 mg, while the patient-controlled group used the least anesthesia of all, an average of 52.8 mg, according to the study.

The study found no differences in the time of labor, or the rate of Cesarean deliveries. Neither lower limb strength nor the urge to push was affected by the method used, but there was a trend toward fewer deliveries that required instrument assistance, such as forceps, in the patient-controlled group, the researchers reported.

Women in the patient-controlled group did report slightly higher pain scores when they got to the pushing part of the delivery, but also reported being satisfied with their pain relief overall.

Haydon said that the greater pain when pushing could likely be decreased by allowing patients to give themselves medication more often during that phase of delivery.

"We'd like to move toward more individualized pain care for labor, possibly using an automated delivery system in response to patient needs. This study shows that using less anesthesia seems to be possible with this delivery system," Haydon said.

"My personal belief is that epidurals tend to slow labor down. So, if you can get away with less medication with patient-controlled analgesia, I think it's a wonderful thing," said Dr. Peter Bernstein, a professor of clinical obstetrics and gynecology and women's health at Montefiore Medical Center and Albert Einstein College of Medicine in New York City.

"And, it's not a surprise to me that women used less anesthesia. If you can titrate your own medication, you're probably not going to give yourself a lot. An anesthesiologist will tend to give you a little bit more because they want to make sure there's no pain," explained Bernstein.

More information

Learn more about epidural blocks for pain relief during labor and delivery from the March of Dimes.