After teaching a pregnant woman about the hormones produced by the placenta, the nurse determines that the teaching was successful when the woman identifies which hormone produced as being the basis for pregnancy tests?

Choice A. Accelerations are normal responses that indicate the fetus is healthy and active. Accelerations occur when the fetal heart rate increases in response to stimuli. •

Choice B. Late decelerations are nonreassuring patterns that indicate fetal hypoxia due to placental insufficiency. Late decelerations occur when the placental blood flow decreases due to uterine contractions during labor, causing the fetal heart rate to decrease. •

Choice C. Variable decelerations are nonreassuring patterns that indicate fetal hypoxia due to umbilical cord compression. Variable decelerations occur when the umbilical cord is trapped by the cervical opening or the fetal body part, twisted, or knotted, causing the fetal oxygen supply to be impaired and the fetal heart rate to drop sharply. •

Choice D. Early decelerations are reassuring patterns that indicate a neural reflex due to fetal head compression. Early decelerations occur when the fetal head is compressed by uterine contractions during labor, causing the parasympathetic nervous system to be stimulated and the heart rate to decrease. The correct answer is C. Variable decelerations are the most common pattern that indicates a problem with the umbilical cord and requires urgent intervention.

Choice A reason:

Maternal exhaustion is a maternal indication for the use of vacuum extraction. Vacuum extraction is a technique that can assist the mother in delivering the baby when she is unable to push effectively or when pushing poses a risk to her health. Vacuum extraction can shorten the second stage of labor and reduce maternal fatigue and distress. According to the Cleveland Clinic, vacuum extraction might be indicated if "the mother can't push anymore, either due to exhaustion or a health condition.".

Choice B reason:

Failure to progress past 0 station is not a maternal indication for the use of vacuum extraction. The station refers to the position of the baby's head in relation to the mother's pelvis. 0 station means that the baby's head is at the level of the pelvic inlet, or the narrowest part of the pelvis. Vacuum extraction is usually not performed before the baby reaches +2 station, which means that the head is 2 cm below the pelvic inlet and visible at the vaginal opening. According to the American Academy of Family Physicians, vacuum extraction should not be attempted if "the fetal head is not engaged (above 0 station).".

Choice C reason:

A wide pelvic outlet is not a maternal indication for the use of vacuum extraction. The pelvic outlet is the lower part of the pelvis that forms the exit for the baby during delivery. A wide pelvic outlet means that there is more space for the baby to pass through, which can facilitate vaginal delivery and reduce the need for instrumental assistance. Vacuum extraction is more likely to be indicated when there is a narrow pelvic outlet, which can obstruct labor and cause fetal distress.

Choice D reason:

A history of rapid deliveries is not a maternal indication for the use of vacuum extraction. Rapid deliveries, also known as precipitous deliveries, are those that occur within 3 hours of the onset of labor. Rapid deliveries can pose risks to both the mother and the baby, such as excessive bleeding, umbilical cord prolapse, or birth trauma. However, vacuum extraction is not usually indicated in these cases, as it requires time and preparation to apply the device and monitor its effects. Vacuum extraction is more likely to be indicated when labor is prolonged or stalled in the second stage, and when there is a nonreassuring fetal heart rate.