A nurse is evaluating the fetal heart rate tracing of a client who is in pre-term labor and receiving magnesium sulfate.

The nurse should identify that which of the following patterns indicates a potential adverse effect of the medication on the fetus?

Tocolytics are a category of drugs used to delay the labor process.These may be used in situations when a pregnant person begins showing signs of preterm labor —which is any time before 37 weeks of completed pregnancy.Tocolytics may help delay labor by two to seven days.

Some possible explanations for the other choices are:

• Choice A. Administering intravenous fluids.

This is not a correct answer because intravenous fluids are not effective in suppressing uterine contractions.They may be used to correct dehydration or electrolyte imbalance, which can sometimes trigger preterm labor, but they are not a primary intervention for preterm labor.

• Choice C. Administering corticosteroids.

This is not a correct answer because corticosteroids are not tocolytics.They do not stop or slow down uterine contractions, but they help accelerate fetal lung maturity and reduce the risk of neonatal respiratory distress syndrome and other complications of prematurity.

Corticosteroids are often given along with tocolytics, but they have a different function and mechanism of action.

• Choice D. Administering antibiotics.

This is not a correct answer because antibiotics are not tocolytics.They may be used to treat infections that can cause or complicate preterm labor, such as chorioamnionitis or group B streptococcus, but they do not directly affect uterine contractions.

Antibiotics may be given along with tocolytics, but they have a different function.

The client should not limit their physical activity and rest as much as possible, unless advised by their provider.Excessive rest and inactivity can increase the risk of blood clots and decrease blood circulation, which can affect the placenta and the fetus.The client should follow the recommended guidelines for physical activity during pregnancy, unless they have a medical condition that requires bed rest or reduced activity.

Choice A is wrong because smoking and drinking alcohol during pregnancy are known risk factors for preterm labor and birth.Smoking can reduce blood flow to the placenta and affect fetal growth and development, while alcohol can cause fetal alcohol spectrum disorders and other complications.

Choice B is wrong because reporting any vaginal bleeding or fluid leakage to the provider is important to prevent or treat preterm labor and birth.Bleeding can indicate placenta previa or placental abruption, which are serious conditions that can cause premature delivery or fetal distress.Fluid leakage can indicate rupture of membranes, which can increase the risk of infection and preterm labor.

Choice D is wrong because drinking plenty of fluids and eating a balanced diet are beneficial for the health of the mother and the fetus.Dehydration can cause uterine contractions and trigger preterm labor, while malnutrition can affect fetal growth and development.A balanced diet can also help prevent or manage conditions like diabetes, high blood pressure, and anemia, which are risk factors for preterm labor and birth.