Question

During pregnancy, the production of ova is prevented by
A. Estrogen
B. Relaxin
C. Progesterone
D. Prolactin

Answer 1

Hint: During the pregnancy period many hormones play key roles such as estrogen, progesterone, human chorionic gonadotropin hormone, and human placental lactogen. The important pregnancy hormones are estrogen and progesterone.

Complete answer:
-Estrogen: Estrogen plays an essential role in proliferation. FSH (follicle-stimulating hormone) controls the release of estrogen and it mainly regulates the menstrual cycle. Estrogen helps in uterus growth and also maintains the uterine lining.
-Relaxin: Relaxin produced by the ovary and the placenta with important effects during pregnancy in preparation for the parturition or childbirth, it relaxes the ligaments in the pelvis and softens and widens the cervix.
-Progesterone: During pregnancy the first three months progesterone is produced by the corpus luteum and in the last six months, it is produced by the placenta. Progesterone maintains endometrial lining and it also prevents any new follicle development, and it also suppresses the immune response of the mother against the foetal antigens.
-Prolactin: Prolactin hormone is important at the end of the pregnancy as it stimulates breast milk production or lactation after childbirth. When progesterone levels decrease Prolactin is produced and it enlarges the mammary glands and prepares them for milk production.

Hence, the correct answer is option (C).

Note: Progesterone supports the pregnancy by maintaining uterine thickening and implantation of the fertilized egg on the uterus wall. This hormone is first secreted by the corpus luteum then by placenta. Progesterone hormone is also termed as the pregnancy hormone.