This hormone from your ovaries relaxes and softens the ligaments, cartilage and cervix, making these tissues more stretchable and letting the pelvic joints spread during birth.

• A. Estrogen
• B. Relaxin
• C. Progesterone
• D. Prostaglandins

Answer: (B)

Relaxin is the hormone produced by the ovaries during pregnancy that loosens ligaments, cartilage, and the cervix to prepare the body for birth. By increasing tissue pliability, it allows the pelvic joints and the cervix to stretch and widen as labor progresses, helping the baby pass through the birth canal. Estrogen supports uterine growth and cervical changes in other ways, progesterone helps maintain pregnancy by keeping the uterus calm, and prostaglandins contribute to cervical ripening and labor but are not the ovarian hormone whose hallmark effect is softening and loosening pelvic tissues.