FDA approval may be around the corner for a higher concentration, time-release version of the labor induction drug misoprostol (Cytotec). Currently, misoprostol is used in pregnancy to ripen the cervix and cause contractions. This is an off-label use, meaning its use in this manner is not approved by the Food and Drug Administration (FDA). In current practice, misoprostol is given in 25-microgram doses, inserted vaginally. Safety concerns are an issue with misoprostol because it has severe side-effects, including hyperstimulation. Hyperstimulation, also called tachysystole, occurs when uterine contractions are so strong and frequent that the placenta has very little or no time to be replenished with a fresh supply of oxygen-rich blood. In other words, the contractions almost continuously constrict the blood vessels that bring oxygen-rich blood from the mother to the baby through the placenta and umbilical cord. When tachysystole occurs, the baby can become deprived of oxygen, which can cause brain injury, such as hypoxic ischemic encephalopathy (HIE). Tachysystole also can cause the uterus (womb) to rupture, which can cause brain injury in the baby, as well as be life threatening for both mother and baby.
The new time-release version is a 200-microgram concentration (dose) that is delivered in a removable vaginal insert in which misoprostol is released at a controlled rate for up to 24 hours. A recent study that compared this new version to a 10-microgram, non-time released labor induction drug, called dinoprostone, found that women given the misoprostol delivered more quickly than those who received the dinoprostone.
200-MICROGRAM MISOPROSTOL STUDY
Deborah A. Wing, M.D., from the University of California at Irvine, and colleagues randomly assigned women being induced with a modified Bishop score of 4 or less to receive either the 200-microgram misoprostol vaginal insert (678 patients) or the 10-mg dinoprostone vaginal insert (680 patients). A Bishop score is a grading scale used to help determine the likelihood of success of labor induction.
The researchers found that women receiving the misoprostol insert had a significantly shorter median time to vaginal delivery compared with patients receiving the dinoprostone insert (21.5 hours versus 32.8 hours). Twenty-six percent of women receiving the misoprostol insert and 27.1 percent of those with the dinoprostone insert had a C-section delivery. The misoprostol insert was significantly associated with a reduction in time to any delivery (18.3 versus 27.3 hours), time to onset of active labor (12.1 versus 18.6 hours), and proportion of women requiring pre-delivery oxytocin (48.1 versus 74.1 percent), compared with the dinoprostone vaginal insert. Participants experienced tachysystole requiring intervention in 13.3 and 4.0 percent of cases receiving the misoprostol insert and dinoprostone insert, respectively.
“Use of a 200-microgram misoprostol vaginal inset significantly reduced times to vaginal delivery and active labor with reduced need for oxytocin compared with the dinoprostone vaginal insert,” the authors write. Oxytocin is another labor induction drug.
The researchers listed several limitations of this study, which included noting that tachysystole identification in the study may be overestimated or underestimated. In addition, the dinoprostone insert was allowed to remain in place for up to 24 hours, which is beyond the approved 12 hour use in the U.S.
Experts have questioned this study’s applicability to actual practice since the study doesn’t mention anything about misoprostol as it typically is used in current practice. One physician stated that the trial does not justify clinical use of the 200-microgram misoprostol insert.
200-MICROGRAM MISOPROSTOL AND BIRTH INJURY
Of great importance in the study is the fact that half of the women in the misoprostol group experienced tachysystole compared with a quarter of women using dinoprostone. Increasing the number of contractions during labor may speed up the process of labor and delivery, but it also increases the risk of oxygen deprivation to the baby, as well as injury to the mother.
In addition to an increased risk of insufficient oxygen and HIE, tachysystole increases the chances of uterine rupture. A ruptured uterus occurs when excessive and strong contractions cause stress on the uterus, thereby causing it to tear, either partially or completely. When the uterus tears, the mother can experience severe bleeding. This bleeding can cause a lack of oxygen-rich blood to be delivered to the baby. Furthermore, the tear may cut off the placenta from the mother’s circulation, causing reduced or no blood flow through the umbilical cord to the baby, which also can deprive the baby of oxygen and cause HIE.
When a baby is experiencing oxygen deprivation and is in distress, an emergency C-section must be performed to remove the baby from the distressful conditions. The longer a baby is deprived of oxygen, the more likely it is that she will experience HIE and brain damage.
Indeed, studies such as this one should be viewed with caution. The 200 microgram version of misoprostol may speed up delivery, but it may also increase the likelihood of birth injuries. Risks and benefits must be carefully weighed in situations of labor induction, especially when such a risky drug is used. The mother must be adequately informed of all the risks and benefits of the labor induction drug / drugs that are administered, and she and the baby must be closely monitored during labor and delivery. Furthermore, informed consent must be given for type of delivery, such as a C-section versus vaginal delivery.
HELP FOR VICTIMS OF CYTOTEC / MISOPROSTOL INJURIES
If you or your child were injured during childbirth and you believe that you were given Cytotec / misprostol in any form, we invite you to contact Reiter & Walsh ABC Law Centers: Birth Injury Lawyers for a free consultation. Our nationally recognized firm specializes in complex birth injury cases, and we have over 30 years of experience in this area. Our attorneys will carefully review all medical records, determine if Cytotec contributed to your child’s injuries, and if so, obtain the compensation your child deserves. Call us at 888-419-2229.