April 1 2004 • Volume 39 • Number 7

Obstetrics

 

Bruce Jancin
Denver Bureau

BIG SKY, MONT. — Oral misoprostol is far and away the most cost effective labor induction method, Dr. Arthur S. Maslow asserted at a meeting on ob.gyn., gynecologic oncology, and reproductive endocrinology.

“The best part about it is that you can block-schedule your nurses so that you have enough on hand. With a 90% successful induction rate within 8-10 hours, if we start our inductions at 7 a.m., we know that we're going to have X number of patients in labor being admitted by 4 p.m. That's helped our hospital tremendously,” said Dr. Maslow, director of maternal and fetal medicine at the Geisinger Health System in Danville, Pa.

Five randomized trials of oral misoprostol (Cytotec) have demonstrated that this off-label labor induction technique is as good as or better than other methods in terms of safety, cost, induction/delivery time, and neonatal and maternal outcomes.

This randomized trial experience has now been supplemented by a soon-to-be-published study by Dr. Maslow and coinvestigators involving 2,200 consecutive elective inductions using oral misoprostol. The inductions were conducted in a private-practice setting in an antepartum diagnostic center located within a hospital in Tacoma, Wash., where Dr. Maslow practiced before his recent move to Geisinger.

Ninety percent of treated patients were ready for artificial rupture of membranes or delivered within 8-10 hours.

“It's a great agent. It works very, very efficiently. It's very safe. We've had no complications, no uterine ruptures. And it's ungodly inexpensive: 27 cents per tablet. At the most we use two or three tablets,” Dr. Maslow said at the meeting, sponsored by the Geisinger Health System.

Although intravaginal misoprostol for labor induction has its devotees, Dr. Maslow views the oral route as making “perfect sense.” Plasma levels climb rapidly following oral ingestion, peaking at 1 hour and returning to baseline by 2-3 hours. In contrast, peak levels are lower with intravaginal misoprostol and remain elevated for 6 hours or more.

“That's probably the reason for the reports of uterine hyperstimulation that we sometimes see in the literature, which probably have to do with polysystole and not hypertonus,” he continued.

Dr. Maslow urged his colleagues to give oral misoprostol a try, and he offered several tips based upon his extensive experience. First, gather a core group of nurses who really want to learn how to manage the latent phase of labor in this way. Approach oral misoprostol as a true induction agent as opposed to a cervical ripening agent. Adhere to a strict protocol. And use the drug only in the hospital.

“I don't recommend using it in somebody's office,” the physician stressed. “If you're going to get in trouble, you want to be in trouble in the hospital; you don't want to be in trouble somewhere else.”

The only contraindications to labor induction using oral misoprostol are prostaglandin allergy, which is rare, and a scarred uterus. However, before the declared moratorium on the use of the drug in women with a scarred uterus, Dr. Maslow and his colleagues used the agent in 61 women with a prior, single, low transverse uterine incision; none experienced any problems.

The protocol he and his colleagues use for elective induction of labor involves having patients arrive at the antepartum diagnostic center first thing in the morning. There they are monitored for 15 minutes. Then their cervix is checked and their Bishop score is recorded before they receive a single oral 50-µg tablet of misoprostol. They are monitored for the next hour as their plasma drug level climbs.

“Then we make them walk for 2 hours. They can stay in the hospital, go to the mall, I don't care. Just don't rest them during an induction. You're killing your hospital financially if you do that, just killing them. It's not fair to the hospital, and it's certainly not fair to the patient,” Dr. Maslow said.

At the 2-hour mark, the patient's cervix is rechecked and she is once again monitored for 15 minutes. If all is well but her cervix hasn't dilated to 2-3 cm and hence she's not yet ready for artificial rupture of membranes, she receives a second 50-µg dose, and the monitoring and walking sequence is repeated. A maximum of three doses is used.

Dr. Maslow said he'll occasionally give a fourth dose if a patient is progressing but not yet ready for artificial rupture of membranes; however, he doesn't recommend that others do this until they've amassed considerable experience. Alternatively, the patient can be switched at that point to oxytocin or another method of induction, with the caveat that oxytocin shouldn't be started until 3 hours after the last dose of oral misoprostol.

Only 17 women in his 2,200-patient series had absolutely no cervical change after three doses of misoprostol. All moved on to other induction methods—and all 17 ultimately had a cesarean section.