Dear Dr. Marc......is my progesterone too low?

Dear Dr. Marc,

I have a question that might be silly, but my progesterone level came back low after my intrauterine insemination (IUI).   You put me on progesterone to increase my level I'm guessing.  Does having low progesterone mean the chance of me being pregnant are very small?  My friend said that my chance is super low now. Is this true? I know nothing about this so I thought I'd ask.  Will I always have low progesterone?

Thanks for your time

Progesterone Confusion

Dear Progesterone Confusion,

Your question is definitely not silly and I am glad that you asked : )To properly answer, first let me explain a little bit about the natural physiology of progesterone. 

There are 2 major hormones produced by the ovary during a natural menstrual cycle, estrogen and progesterone.  The first half of the cycle (the time from the first day of your period until ovulation) is pretty much dedicated to the production of estrogen.  Estrogen has a number of jobs during this time, one of the most important is to stimulate growth of the endometrium (lining of the uterus). 

Once ovulation (release of the egg) occurs, the ovary transitions from producing estrogen to producing progesterone.  Progesterone acts to modify and support the endometrium, making it receptive to a potential embryo. Normally, the progesterone starts off low at the time of ovulation and then increases until it peaks at a level of about 10 -15 ng/ml 1 week after ovulation.  If pregnancy does not occur, a week later, the progesterone decreases and menstruation ensues. 

 Now as far as your question, your progesterone was 3.25 ng/ml.  This implies that 1 of 2 things happened.

1.       You many have ovulated later than we predicted.  Despite the positive ovulation prediction kit, the estrogen level and our ultrasound estimates, we are occasionally wrong about the timing of ovulation.  If that was the case, then we actually checked the progesterone too early.  This would explain why it is on the low side.  In this case, it is not a problem because it will probably rise as time goes on.

2.       You might simply produce less progesterone than average.  3.25 is a pretty low level, but there is significant variation from one person to another.  If that is the case, the supplementation can be very helpful.

In terms of pregnancy, a low progesterone level does not preclude pregnancy from occurring.  However, at 3.25, I am more concerned that you may have ovulated later, thus it might be more of a timing issue. 

Either way, the supplementation can be helpful and if this does not result I pregnancy, using some medication to help with the timing of ovulation may be just what we need. 

I hope this is all clear, if you have any questions, please don’t hesitate to contact us.

Best,

Dr. Marc