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

Choice A reason: This is incorrect because oral antiviral therapy is not effective for PID, which is caused by bacterial infection. Antiviral therapy is used for viral infections, such as herpes or HIV.

Choice B reason: This is incorrect because antibiotics only until symptoms subside is not sufficient for PID, which can cause serious complications, such as infertility, ectopic pregnancy, or chronic pelvic pain. Antibiotics should be continued for the full course of treatment, usually 14 days, to ensure complete eradication of the infection.

Choice C reason: This is incorrect because frequent pelvic examination to monitor the progress of healing is not recommended for PID, which can cause inflammation and irritation of the pelvic organs. Pelvic examination should be avoided or minimized to prevent further trauma or spread of the infection.

Choice D reason: This is correct because bed rest in a semi-Fowler position is beneficial for PID, which can cause fluid accumulation and pressure in the pelvic cavity. Bed rest helps to reduce inflammation and pain, while semi-Fowler position helps to drain the fluid and prevent abscess formation.

Choice A reason: A total placenta previa is when the placenta completely covers the internal os, blocking the baby's exit from the uterus.

Choice B reason: Placenta previa is a condition where the placenta implants in the lower uterine segment and may cover or be near the cervical internal os. When the placental edge just reaches the internal os but does not cover it, it is called a marginal previa.

Choice C reason: A complete placenta previa is when the placenta partially covers the internal os, reducing the space for the baby to pass through.

Choice D reason: "Partial placenta previa" refers to a situation where the placenta partially covers the internal cervical os — meaning some, but not all, of the opening is obstructed by placental tissue.