A woman diagnosed with marginal placenta previa gave birth vaginally 15 minutes ago. At the present time she is at the greatest risk for:

Choice A reason: Vibroacoustic stimulation is a technique that uses sound to stimulate the fetus and elicit a response. It is sometimes used in conjunction with the nonstress test (NST), not the CST. The NST measures the fetal heart rate (FHR) in response to fetal movement, while the CST measures the FHR in response to uterine contractions.

Choice B reason: A negative CST result means that the FHR does not show any late decelerations during at least three contractions in a 10-minute period. 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 indicate uteroplacental insufficiency, which means that the placenta is not delivering enough oxygen and nutrients to the fetus. A negative CST result is reassuring and suggests that the fetus is well-oxygenated and can tolerate labor².

Choice C reason: The CST is not an invasive test, as it does not involve inserting any instruments or devices into the uterus or the fetus. However, it does require stimulating contractions, either by giving the pregnant woman oxytocin (a hormone that causes uterine contractions) or by having her rub her nipples (which also releases oxytocin). The contractions can be uncomfortable and may trigger preterm labor in some cases.

Choice D reason: The CST is not more effective than the NST if the membranes have already been ruptured. In fact, the CST is contraindicated (not recommended) in women who have ruptured membranes, as it can increase the risk of infection and bleeding. The NST is a safer and simpler alternative to the CST, as it does not require stimulating contractions. However, the NST may not be as reliable as the CST in detecting fetal compromise.

Choice A reason: HSV-2 is a viral infection that causes genital herpes. It is transmitted through sexual contact and can cause painful blisters and ulcers in the genital area. The primary infection is usually the most severe and lasts for several weeks. After the primary infection, the virus remains dormant in the nerve cells and can reactivate periodically, causing recurrent episodes of genital herpes. The frequency and severity of the recurrences vary from person to person.

Choice B reason: HPV is a viral infection that causes genital warts and cervical cancer. It is transmitted through sexual contact and can infect the skin and mucous membranes of the genital area. The primary infection is often asymptomatic and may clear spontaneously or persist for years. HPV does not cause recurrent episodes of genital warts or cervical cancer, but it can increase the risk of developing these conditions over time.

Choice C reason: CMV is a viral infection that causes flu-like symptoms and can affect various organs. It is transmitted through bodily fluids such as saliva, urine, blood, and semen. The primary infection is usually mild and may go unnoticed. After the primary infection, the virus remains latent in the body and can reactivate in people with weakened immune systems, causing serious complications. CMV does not cause recurrent episodes of flu-like symptoms or organ damage, but it can worsen the condition of people with HIV or AIDS.

Choice D reason: HIV is a viral infection that causes acquired immunodeficiency syndrome (AIDS). It is transmitted through sexual contact, blood transfusion, or sharing of needles. The primary infection is often accompanied by flu-like symptoms and lasts for a few weeks. After the primary infection, the virus gradually destroys the immune system and makes the person vulnerable to opportunistic infections and cancers. HIV does not cause recurrent episodes of flu-like symptoms or AIDS, but it can progress to AIDS over time.