North American Registry of Midwives (NARM) Practice Exam

What does HCG do during the first trimester of pregnancy?

1. Maintains the corpus luteum

2. Stimulates follicle development

3. Increases blood flow to the uterus

4. Promotes the growth of the placenta

The correct answer is: Maintains the corpus luteum

During the first trimester of pregnancy, human chorionic gonadotropin (HCG) plays a crucial role by maintaining the corpus luteum. The corpus luteum is a temporary endocrine structure formed after ovulation, which produces progesterone essential for maintaining the uterine lining and supporting an early pregnancy. When a pregnancy is established, HCG is secreted by the developing placenta shortly after implantation. Its primary function during this period is to signal the corpus luteum to continue producing progesterone, thus preventing its degeneration. This action is vital as progesterone supports the development of the embryos and helps maintain pregnancy until the placenta is sufficiently developed to take over hormone production. Other options such as stimulating follicle development or increasing blood flow to the uterus do not accurately reflect the primary role of HCG in this stage of pregnancy. While blood flow to the uterus does increase due to various factors, HCG's specific function is centered on supporting and maintaining the corpus luteum, making it instrumental in the early stages of gestation. Additionally, while HCG does play a role in promoting the growth of the placenta, this occurs later in pregnancy, after the initial maintenance of the corpus luteum has taken place.