Question

The hormone responsible for maintaining the pregnancy is :
A. Prolactin
B. Oxytocin
C. Estrogen
D. Progesterone

Answer 1

Hint: Main hormones that play a vital role in pregnancy are estrogen, progesterone, human chorionic gonadotropin hormone, and human placental lactogen. Estrogen and progesterone are chief pregnancy hormones.

Complete answer: Progesterone mainly controlled by luteinizing hormone plays an important role in the implantation of fertilized eggs on the uterus wall.
Before pregnancy: Progesterone prepares the uterus for pregnancy. It leads to the starting of the luteal phase and also causes the endometrium lining to thicken for implantation. After implantation progesterone reaches its peak level.
During pregnancy: During the first three months progesterone is produced by the corpus luteum and in the last six months is produced by the placenta. It maintains an endometrial lining and also prevents any new follicle development. Also, progesterone suppresses the immune response of the mother against foetal antigens.
-Prolactin is important at the end of pregnancy for milk production or lactation. When progesterone levels decrease prolactin is produced. Prolactin enlarged the mammary gland and prepare them for milk production.
-Oxytocin plays an important role at the time of delivery as it helps in the contraction of the cervix. It also leads to myometrial contractions at the time of labour.
-Estrogen plays an important role in proliferation. FSH mainly controls the release of estrogen. Estrogen mainly regulates the menstrual cycle whereas progesterone supports a pregnancy.
Hence, the correct answer is option D.

Note: Progesterone supports pregnancy in maintaining uterine thickening and implantation . It is secreted by the corpus luteum initially and then by the placenta. Progesterone is also called the pregnancy hormone. Oxytocin plays an important role during labour, estrogen during the menstrual cycle and follicular development, and prolactin are important for lactation.