Timing Progesterone Supplementation
Question
Hello. I have one child who was easily conceived (second month of trying with charting). We are now trying for #2 and have been charting for seven months. I have found that my luteal phase is short (ranges from 7-12 days with an average of ten) so I called my OBGYN. He prescribed progesterone pills that I am to begin taking on day 14 of my cycle and take for 12 days, however, I don’t typically ovulate until day 26 of my 36 day cycle. From what I have read, taking progesterone BEFORE I ovulate could cause me NOT to ovulate. So, should I wait to take the progesterone until my chart shows that I have ovulated (I do ovulate regulary just later than typical) and then take the 12 pills?
If I do that, my second question is: If I do get pregnant and I quit taking the progesterone pills 12 days after ovulating could that cause a miscarriage? I have read that I should continue taking them through the first trimester and some even say throughout the second trimester as well. If this is the case, why did my doctor only prescribe 12 pills?
Thanks for any help you can provide!
Kelly O’Toole
Answer
Last Updated: December 1, 2021
Thank you for your question regarding 36 day cycles, and the use of progesterone on day 14 of your cycle for a short luteal phase.
The protocol in the Creighton Model of NFP uses cooperative progesterone replacement therapy which must be provided only during the postovulatory phase of the cycle.
Picking any given day of the cycle to measure progesterone is not useful because of the variability of the preovulatory phase and we know ovulation occurs on day 14 in only 13.5% of cycles. The Peak Day is the most reliable sign of the day of ovulation. (We know also that ovulation will occur within two days before and two days after the Peak Day in 95% of cycles.) Progesterone is measured from Peak +3 through Peak +12. Progesterone support will not work if it is not give at the right time.
So in your case you need to let your OBGYN know when you ovulate which you say is day 26, and if that is the Peak Day for you, that is the correct placement from which to start. You would start the Progesterone on Peak +3.
Yes, sometimes the Progesterone regime is continued during pregnancy.
I would suggest you have your Progesterone levels checked in the post ovulatory phase on days 3,5,7,9, before achieving a pregnancy. You may also have your thyroid levels checked. Then when you are pregnant to also have your levels checked early, to see that it is adequate or if you need to continue the replacement.
You do not say anything about which method you are using and how your mucus cycle is, so perhaps you can call a teacher in your area and get some more information.
Wishing you and your husband much blessings.
Theresa Mitchell RN
Answered By:
