Which hormone is produced by the placenta to sustain pregnancy and is used in pregnancy testing?

• A. Hysterosalpingography
• B. Lumbar puncture (spinal tap)
• C. Human chorionic gonadotropin (hCG)
• D. Laparoscopy

Answer: (C)

The placenta secretes human chorionic gonadotropin, or hCG, to keep pregnancy going. hCG supports the corpus luteum in early gestation, which continues producing progesterone to maintain the uterine lining until the placenta is ready to take over. Because hCG is produced only during pregnancy and rises quickly once implantation occurs, it becomes the testable marker for pregnancy in blood or urine. Serum hCG can be detected relatively early, within about one to two weeks after conception, while urine tests generally become positive a bit later. The other options are not hormones or related to pregnancy testing: they are imaging or surgical procedures.