Which hormones are crucial for maintaining pregnancy?

The hormones progesterone and estrogen play vital roles in maintaining pregnancy. Progesterone is essential for preparing the uterine lining for implantation of the fertilized egg and helps to sustain the pregnancy by preventing contractions of the uterus and promoting a conducive environment for fetal development. Estrogen, on the other hand, supports various functions during pregnancy, including the growth of uterine tissues, the development of the placenta, and the regulation of other hormones essential for pregnancy progress.

While other hormones mentioned in the options do have roles in the reproductive cycle, they are not primarily responsible for sustaining an ongoing pregnancy. Oxytocin and relaxin are involved in labor and childbirth, but not in the maintenance of pregnancy itself. Testosterone is involved in several reproductive functions but is not crucial for maintaining pregnancy. Similarly, follicle-stimulating hormone and luteinizing hormone are important for ovulation and reproductive function but do not have a role once pregnancy is established. Hence, the combination of progesterone and estrogen is crucial to the successful maintenance of pregnancy.