Which presumptive sign (felt by the woman) or probable sign (observed by the examiner) of pregnancy is not matched with another possible cause?

Choice A reason: This is incorrect because a donor embryo is not used in IVF-ET. A donor embryo is an embryo that was created from another couple's gametes and donated to an infertile couple. IVF-ET uses the couple's own gametes to create an embryo.

Choice B reason: This is incorrect because it is dismissive and unprofessional. The nurse should respect the husband's curiosity and provide accurate and clear information about the procedure. The nurse should also address any concerns or questions that the couple may have.

Choice C reason: This is correct because it is a concise and accurate description of the IVF-ET procedure. The nurse explains the main steps and the purpose of the procedure in simple terms.

Choice D reason: This is incorrect because donor sperm is not used in IVF-ET. Donor sperm is sperm that was obtained from another man and donated to an infertile couple. IVF-ET uses the husband's own sperm to fertilize the wife's eggs.

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.