From the Research
Progesterone levels in pregnancy are typically around 10-12 ng/mL in the first trimester, increasing to 100-200 ng/mL by the third trimester, with the most recent and highest quality study suggesting a cut-off value of <6.3 ng/mL to detect non-viable pregnancy 1. The hormone progesterone plays a crucial role in maintaining pregnancy, and its levels are essential for preparing the uterine lining for implantation, reducing uterine contractions, and supporting placental development. Key points to consider include:
- Progesterone levels increase significantly during pregnancy, with the placenta taking over as the primary source of production after about 8-10 weeks 2.
- Abnormally low progesterone levels may indicate potential complications such as threatened miscarriage or ectopic pregnancy, highlighting the importance of monitoring progesterone levels in early pregnancy, especially in women with a history of pregnancy loss 3.
- A single progesterone level can provide clinically useful prognostic information on pregnancy viability, with more than nine out of ten patients with a level <6.3 ng/mL likely to be diagnosed with a non-viable pregnancy 1.
- Progesterone supplementation may be prescribed for women with recurrent pregnancy loss or those undergoing fertility treatments, underscoring the importance of progesterone in maintaining a healthy pregnancy 4.