Progesterone is one of the hormones essential for female reproduction. Progesterone, produced by the corpus luteum, the remaining remnant of the follicle that once contained the developing egg, helps maintain a pregnancy, should one occur. When progesterone levels fall, the uterine lining deteriorates and a new menstrual cycle starts. Progesterone levels at the beginning of the menstrual cycle average less than 1 nanogram per milliliter, or ng/mL. Progesterone levels rise to around 15 ng/mL or more after ovulation, according to Dr. Malpani of Malpani Fertility Clinic. Low levels of progesterone, which can be caused by problems with the corpus luteum, can cause several symptoms.
Abnormal Bleeding
Abnormal bleeding occurs between ovulation and the next menstrual period if progesterone levels aren't high enough to sustain the thickened uterine lining that develops in anticipation of embryo implantation. Breakthrough bleeding from low progesterone differs from spotting sometimes seen when the embryo first begins to burrow into the uterine lining, called implantation bleeding. It's impossible to determine the type of bleeding without checking serum levels of progesterone.
Shortened Luteal Phase
The luteal phase describes the period of time between ovulation and the start of the next menstrual cycle. The normal luteal phase consistently lasts between 10 and 14 days, GYNOB.com states. The variation of menstrual cycles most women experience is due to variations in the length of time between the start of a new cycle and ovulation. A luteal phase that lasts 10 days or less indicates low progesterone levels that drop too low to sustain the uterine lining. A short luteal phase is also called a luteal phase defect.
Early Recurrent Miscarriage
Up to 5 percent of women who have early recurrent miscarriages may have low progesterone levels that don't maintain the uterine lining, resulting in the loss of the growing embryo, HealthCentral reports. While chromosomal abnormalities cause the majority of miscarriages in the first three months of pregnancy, according to California State University Health Resource Center, low progesterone levels may cause pregnancy loss before a period is even missed. The only sign of possible miscarriage may be an exceptionally heavy menstrual period.
References
- HealthCentral.com: Luteal phase defect
- California State University Health Resource Center: Miscarriage
- Malpani Infertility Clinic: What is Progesterone?
- "Therapeutics and Clinical Risk Management"; Luteal phase support in assisted reproductive technology treatment; Jerome Check, M.D.; May 21, 2009
- GYNOB.com: Luteal Phase Defect
