Progesterone is a hormone that usually comes from the corpus luteum after ovulation. Measuring progesterone levels can determine if you ovulated or not. Low progesterone levels may be a problem. When you ovulate there is an area in the ovary called "corpus luteum" which is responsible for the production of progesterone. Low progestone levels below 10 ng/ml usually mean that ovulation has likely not happened or you tested too early, less than a week after ovulation.
Pregnancy cannot be diagnosed in and by itself from progesterone levels, only the presence of hCG the pregnancy hormone in the blood or urine diagnoses a pregnancy. Progesterone levels alone cannot diagnose a pregnancy. Progesterone cream cannot be used after ovulation to improve fertility or pregnancy outcome.
- Progesterone levels after ovulation (midluteal, middle of the second half of the cycle) in a nonpregnant patient are generally at least 8-10 ng/ml. Much lower levels usually mean you did not ovulate.
- Progesterone levels can change from one day to the other, from one hour to the next, from one laboratory to the next.
- After you eat, progesterone levels can drop by as much as 50%, that's why the blood test should be done in the morning and before you eat.
- Even on the same day women may have different levels.
- Progesterone levels are usually well below 5-10 ng/ml without ovulation.
- If you are pregnant, progesterone levels are usually at least 10-12 ng/ml to have a better chance of a good pregnancy outcome and most doctors like to see progesterone levels around 16-18 ng/ml or more though there are many successful pregnancies with lower levels.
- With an ectopic pregnancy, progesterone levels are lower when compared with an intrauterine pregnancy.
- There are differences in opinion as to what to do if progesterone levels are low after ovulation.
- Some doctors suggest giving progesterone (pills, shots, or suppositories) but many others do not treat unless you have IVF or injectable ovulation medications or if there has been proof of a preexisting low progesterone in nonpregnancy cycles and there are immune issues leading to miscarriages.