Examples of sexual risk behaviors associated with exposure to a sexually transmitted infection (STI) include: (Select all that apply.)

Choice A reason: Variability refers to the fluctuations in the FHR that are irregular in amplitude and frequency. It reflects the balance between the sympathetic and parasympathetic nervous systems of the fetus. A normal variability is between 6 and 10 beats/min, which indicates a healthy and well-oxygenated fetus.

Choice B reason: Late decelerations are decreases in the FHR that begin after the peak of a contraction and return to the baseline after the contraction ends. They are caused by uteroplacental insufficiency, which means that the placenta is not delivering enough oxygen and nutrients to the fetus. Mild late decelerations are not reassuring and may indicate fetal hypoxia or acidosis².

Choice C reason: FHR should change as a result of fetal activity, such as movement, sleep, or stimulation. A change in the FHR indicates a responsive and well-oxygenated fetus. A lack of change in the FHR may indicate fetal distress or compromise.

Choice D reason: The average baseline rate is the mean FHR rounded to increments of 5 beats/min during a 10-minute window, excluding periods of marked variability, accelerations, or decelerations. A normal baseline rate is between 110 and 160 beats/min. A baseline rate between 100 and 140 beats/min is not necessarily abnormal, but it may indicate fetal bradycardia (slow heart rate) or tachycardia (fast heart rate), depending on the gestational age and other factors.

Choice A reason: Amniocentesis for fetal lung maturity is not an expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding. It is a procedure that involves inserting a needle into the amniotic sac to obtain a sample of amniotic fluid, which can be used to assess the fetal lung development. It is usually done in late pregnancy or preterm labor, not in the second trimester.

Choice B reason: Contraction stress test (CST) is not an expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding. It is a test that involves stimulating uterine contractions, either by nipple stimulation or oxytocin infusion, to evaluate the fetal heart rate response. It is used to assess fetal well-being and placental function, not to diagnose the cause of bleeding.

Choice C reason: Internal fetal monitoring is not an expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding. It is a method of measuring the fetal heart rate and uterine contractions using electrodes or catheters that are inserted through the cervix and attached to the fetal scalp or the amniotic sac. It is usually done during labor, not in the second trimester.

Choice D reason: Ultrasound for placental location is an expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding. It is a test that uses sound waves to create an image of the uterus, the placenta, and the fetus. It can help to determine the position and attachment of the placenta, which can be the cause of bleeding if it is low-lying or covering the cervix (placenta previa).

Choice E reason: None of the above is not a correct answer. There is one expected diagnostic procedure for a pregnant woman with bright red, painless vaginal bleeding, which is ultrasound for placental location.