A 26-year-old primigravid woman at 42 weeks' gestation comes to the labor and delivery ward for induction of labor. The prenatal course was significant for a positive group B Streptococcus culture performed at 35 weeks. Antenatal testing over the past 2 weeks has been unremarkable. The patient is staed on lactated Ringer's IV solution. Sterile vaginal examination shows that the patient's cervix is long, thick, and closeD. Prostaglandin (PGE2) gel is placed into the vagina, and electronic fetal hea rate monitoring is continueD. In approximately 60 minutes, the fetal hea rate falls to the 90s, as the tocodynamometer shows the uterus to be contracting every 1 minute with essentially no rest in between contractions. Which of the following was most likely the cause of the uterine hyper stimulation?
Prostaglandin (PGE2) gel is widely used for labor induction. In simple terms, it is used "to soften" an unorable cervix, to make the cervix more orable for induction. It has been shown to lead to an improvement in the Bishop's score, a shoer duration of labor, and deliveries. PGE2 gel can also cause uterine contractions. One of the major side effects with PGE2 gel is uterine hyper stimulation. This occurs when uterine contractions come one right after the other, or when there is a tetanic contraction. In this setting, the fetus can become hypoxic with a resultant bradycardia. This patient had the gel placed and 60 minutes later had uterine hyperstimulation. Infection has not been shown to cause uterine hyperstimulation. This patient's group B Streptococcus colonization is likely noncontributory. IV fluids do not cause uterine hyperstimulation. Postdates pregnancy is the reason for this patient's induction and not likely the direct cause of her uterine hyperstimulation. Vaginal examination with a cervical examination can be used for fetal scalp stimulation-rubbing the baby's head to provoke an acceleration of the fetal hea rate. However, this does not usually provoke uterine hyperstimulation.
Infection
IV fluids
Postdates pregnancy
Prostaglandin (PGE2) gel