Growth and Development Q 23
A client telephones the clinic to ask about a home pregnancy test she used this morning. The nurse understands that the presence of which hormone strongly suggests a woman is pregnant?
A. Estrogen
B. Human chorionic gonadotropin (HCG)
C. Alpha-fetoprotein (AFP)
D. Progesterone
Correct Answer: B. Human chorionic gonadotropin (HCG)
Human chorionic gonadotropin (HCG) is the biological marker on which pregnancy tests are based. Reliability is about 98%, but the test does not positively confirm pregnancy. Human chorionic gonadotropin is a hormone produced primarily by syncytiotrophoblastic cells of the placenta during pregnancy. The hormone stimulates the corpus luteum to produce progesterone to maintain the pregnancy.
Option A: Estrogen is a steroid hormone associated with the female reproductive organs and is responsible for the development of female sexual characteristics. Estrogen is often referred to as estrone, estradiol, and estriol.
Option C: Alpha-fetoprotein is a protein produced by a fetus. High levels of AFP can be seen from 12 weeks of pregnancy and peak during the early 3rd trimester but are not used as a confirmatory test for pregnancy.
Option D: Progesterone is an endogenous steroid hormone that is commonly produced by the adrenal cortex as well as the gonads, which consist of the ovaries and the testes. Progesterone is also secreted by the ovarian corpus luteum during the first ten weeks of pregnancy, followed by the placenta in the later phase of pregnancy.