Which hormones influence the flexibility of the female pelvis during pregnancy?

The correct answer is progesterone and relaxin, which play crucial roles in preparing the female pelvis for childbirth. Progesterone helps maintain the pregnancy and supports the softening of the muscles and connective tissues. However, relaxin is particularly significant because its primary function during pregnancy is to increase the flexibility of the pelvic ligaments and joints. This increased flexibility allows the pelvic structure to adapt and expand during labor, facilitating the baby's passage through the birth canal.

Other hormones listed do not significantly contribute to pelvic flexibility during pregnancy. For example, estrogen primarily supports the development of female sexual characteristics and regulates the menstrual cycle, while testosterone is more associated with male characteristics and reproductive functions. Oxytocin and prolactin are important for labor and lactation, respectively, but they do not directly influence the flexibility of the pelvis. Lastly, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are involved in the regulation of the menstrual cycle and ovulation rather than in adjusting the flexibility of the pelvic area during pregnancy.