What is the function of relaxin during the birthing process?

Relaxin plays a crucial role during the birthing process by relaxing the pelvic ligaments. This hormonal change is essential because it allows for increased flexibility in the pelvis, facilitating the passage of the offspring during delivery. As the body prepares for labor, the relaxin hormone helps to soften and expand the connective tissues in the birth canal, making the delivery safer and more efficient.

Other functions mentioned, such as stimulating milk production, promoting oestrus, or increasing metabolic rate, are not directly related to the mechanics of childbirth. While these processes are important in their own right, they do not specifically address the need for pelvic relaxation at the time of birth. Therefore, the primary function of relaxin is clearly linked to aiding in the physical aspect of the birthing process.