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

Choice A reason: Intranasal spray is not a correct option, as urofollitropin is not available in this form. Intranasal spray is a method of delivering some medications through the nose, where they can be absorbed by the mucous membranes. However, urofollitropin is a protein hormone that would be degraded by the enzymes in the nasal cavity and would not reach the bloodstream effectively.

Choice B reason: Intramuscular injection is the correct option, as urofollitropin is available in this form. Intramuscular injection is a method of delivering medications into the muscle tissue, where they can be absorbed by the blood vessels. Urofollitropin is a protein hormone that needs to be injected into the body to bypass the digestive system and avoid being broken down by the stomach acids and enzymes. Urofollitropin is usually injected into the thigh or buttock muscles once a day for several days, depending on the dosage and the response².

Choice C reason: Vaginal suppository is not a correct option, as urofollitropin is not available in this form. Vaginal suppository is a method of delivering medications into the vagina, where they can be absorbed by the vaginal walls or act locally. Urofollitropin is a protein hormone that would not be absorbed well by the vaginal mucosa and would not reach the ovaries, where it is supposed to stimulate the development of the follicles (eggs).

Choice D reason: Tablet is not a correct option, as urofollitropin is not available in this form. Tablet is a method of delivering medications orally, where they can be swallowed and absorbed by the gastrointestinal tract. Urofollitropin is a protein hormone that would be destroyed by the stomach acids and enzymes and would not reach the bloodstream or the ovaries.

Choice A reason: Braxton Hicks contractions are irregular, painless uterine contractions that occur throughout pregnancy. They are a probable sign of pregnancy, not a positive sign.

Choice B reason: Fetal movement palpated by the nurse-midwife is a positive sign of pregnancy, as it confirms the presence of a living fetus in the uterus. It can be detected as early as 16 to 20 weeks of gestation.

Choice C reason: A positive pregnancy test is a probable sign of pregnancy, as it indicates the presence of human chorionic gonadotropin (hCG) in the urine or blood. However, it is not a definitive sign, as other conditions can cause elevated hCG levels.

Choice D reason: Quickening is the first perception of fetal movement by the mother, which usually occurs between 16 and 20 weeks of gestation. It is a presumptive sign of pregnancy, not a positive sign.