What is the normal range for progesterone (P)?

In daily life, many individuals experiencing their first pregnancy are unfamiliar with fundamental reproductive health knowledge. To better assess maternal and fetal health, it is essential to confirm that certain biomarker values fall within normal reference ranges. So, what is the normal range for progesterone (P)?

What is the normal range for progesterone (P)?

During early pregnancy, the normal progesterone range is 63.6–95.4 nmol/L. In the second trimester, it rises to 159–318 nmol/L; in the third trimester, it further increases to 130–1272 nmol/L. A progesterone level above 25 ng/mL during early pregnancy generally rules out ectopic pregnancy. Progesterone levels fluctuate throughout the menstrual cycle: they remain low during the follicular phase, then surge significantly after ovulation due to increased production by the ovarian corpus luteum. Serum progesterone peaks approximately 6–8 days after the mid-cycle luteinizing hormone (LH) surge. During pregnancy, serum progesterone levels rise steadily as gestation progresses, gradually declining to follicular-phase levels about four days before menstruation in non-pregnant cycles. In late pregnancy, progesterone is primarily secreted by the placenta.

Progesterone is a naturally occurring steroid hormone secreted by the ovarian corpus luteum. It exerts pronounced morphological effects on the estrogen-primed endometrium and is indispensable for maintaining pregnancy. Clinically, progesterone is used for the management of threatened abortion, habitual abortion, and diagnostic evaluation of amenorrhea or oligomenorrhea.

During pregnancy, it is advisable to avoid spicy, heavily seasoned, or highly stimulating foods, and instead consume more fresh fruits and vegetables. Maintain regular work and rest schedules, avoid excessive physical exertion, focus on fetal well-being, and attend all scheduled prenatal check-ups. We hope this information proves helpful!