The most common cause of decreased variability in the fetal heart rate (FHR) that lasts 30 minutes or less is:

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: Limiting time spent wearing a wet bathing suit is a good preventive measure, as it can reduce the moisture and warmth that can promote the growth of bacteria and fungi in the genital area. The nurse should advise the 15-year old to change into dry clothes as soon as possible after swimming or bathing.

Choice B reason: Not douching is a good preventive measure, as it can preserve the natural balance of the vaginal flora and pH. The nurse should explain to the 15-year old that douching can wash away the protective mucus and lactobacilli that prevent infections, and it can also introduce harmful substances or microorganisms into the vagina.

Choice C reason: Wearing nylon undergarments is not a good preventive measure, as it can trap heat and moisture in the genital area and create a favorable environment for infections. The nurse should recommend the 15-year old to wear cotton or breathable fabrics that can absorb sweat and allow air circulation.

Choice D reason: Using floral scented bath salts is not a good preventive measure, as it can irritate the genital mucosa and alter the vaginal pH. The nurse should caution the 15-year old to avoid using any products that contain perfumes, dyes, or chemicals in the genital area, as they can cause allergic reactions or infections.

Choice E reason: Decreasing sugar intake is a good preventive measure, as it can lower the risk of yeast infections. The nurse should educate the 15-year old that sugar can feed the growth of Candida albicans, which is a common cause of vaginal candidiasis. The nurse should also encourage the 15-year old to eat a balanced diet that includes probiotics, such as yogurt, to maintain a healthy vaginal flora.

Choice F reason: Avoiding tight-fitting jeans is a good preventive measure, as it can prevent friction and pressure on the genital area. The nurse should suggest the 15-year old to wear loose or comfortable clothing that can reduce the risk of skin irritation or injury, which can lead to infections.