What role does Progesteron play in fertility?

Progesterone plays a central role in fertility, primarily during the luteal phase of the menstrual cycle. After ovulation, the corpus luteum secretes progesterone to prepare the endometrium for embryo implantation. It thickens the uterine lining, reduces uterine contractility, and supports early pregnancy until the placenta takes over. Low progesterone (luteal phase deficiency) can impair implantation or contribute to early miscarriage. The evidence for this role is strong (human-strong), grounded in reproductive endocrinology and clinical practice. However, measuring progesterone levels is only one piece of the fertility puzzle; egg quality, tubal patency, and sperm health are equally critical. Supplementation or hormone therapy should only be guided by a physician after proper testing. Consumer DNA tests like MyBody-X cannot measure progesterone levels; they may report genetic variants in hormone-related genes (e.g., CYP, ESR), but these have small effects and are not diagnostic. A blood test for progesterone is more actionable. Always consult a specialist for fertility concerns.