Which analysis of maternal serum may predict chromosomal abnormalities in the fetus?

Choice A reason: This is not the correct action, as the rate is not within normal limits. A normal FHR at 30 weeks of gestation is between 110 and 160 beats/min. A rate of 82 beats/min is considered bradycardia (slow heart rate), which can indicate fetal distress or hypoxia (low oxygen).

Choice B reason: This is not the first action, but it may be necessary after confirming the FHR. The nurse should first rule out the possibility of a maternal-fetal heart rate confusion, which can occur when the maternal heart rate is mistakenly counted as the FHR. This can happen if the Doppler or the electronic fetal monitor is placed too close to the maternal pulse or if the maternal heart rate is unusually slow².

Choice C reason: This is the correct action, as it can help differentiate between the maternal and the fetal heart rate. The nurse should assess the woman's radial pulse at the same time as listening to the FHR and compare the rates and rhythms. If the rates are the same or very close, it is likely that the nurse is hearing the maternal heart rate instead of the FHR. If the rates are different, it is likely that the nurse is hearing the FHR and that the fetus has bradycardia.

Choice D reason: This is not the correct action, as it may cause unnecessary anxiety or distress for the woman. The nurse should not allow the woman to hear the heartbeat until the FHR is confirmed and the cause of the bradycardia is determined. The nurse should also explain the situation to the woman and provide reassurance and support.

Choice A reason: Magnesium sulfate does not improve patellar reflexes and increase respiratory efficiency. In fact, it may cause hyporeflexia and respiratory depression as adverse effects. These are signs of magnesium toxicity and require immediate intervention.

Choice B reason: Magnesium sulfate does not prevent a boggy uterus and lessen lochial flow. A boggy uterus is a sign of uterine atony, which can lead to postpartum hemorrhage. Lochia is the normal vaginal discharge after childbirth. Magnesium sulfate has no effect on these conditions.

Choice C reason: Magnesium sulfate does not shorten the duration of labor. It may actually prolong labor by relaxing the uterine muscles and inhibiting contractions. Magnesium sulfate is not used to induce or augment labor.

Choice D reason: Magnesium sulfate is used to prevent and treat convulsions in women with preeclampsia and eclampsia. Convulsions are a life-threatening complication of severe hypertension during pregnancy. Magnesium sulfate acts as a central nervous system depressant and anticonvulsant. It reduces the risk of seizures and lowers blood pressure.