From CANFP
Can Ovulation Predictor Kits Help Determine Post Ovulatory Infertility?
By Mary Davenport, MD
Mar 22, 2006, 22:44
Question
My wife and I have been practicing NFP for child spacing up until now, (sympto-thermal). My wife's present medical condition has caused anxiety and scrupulousness in avoiding dry days, and other times early in the cycle -- the anxiety itself being the major problem. (We have sought medical advice already). Presently and for the past two years, low hormonal levels + low motivation have made her charting a source of tension rather than of good.
When I read the FAQ on ovulation prediction kits (OPK), the standard perspective that as a "contraceptive" device they are useless -- since sperm can survive in the fertile mucus for more than two days -- was expressed. However, no mention was made of their effectiveness for determining the *post* ovulation period which is infertile.
In doing web searches, I have come across many slightly conflicting timeframes for ovulation after LH surge is detected. I would like to use the tests for determining the third phase of her cycle (she is open to the idea) but I realize a waiting period is required after the LH surge is detected.
I am not able to accurately determine what a reasonable period would be after the LH surge is detected, since the data varies from site to site. eg: The surge occurs anywhere from 12-24 hours before it is detected, and lasts up to 24 hours BUT Ovulation occurs 1-4 days after the surge, (not the detection), and viability of the egg is ?. etc.
I don't want to be scrupulous myself! But I would like to be able to use the simple ovulation test to releive some of my wife's anxiety. Where/what information is available on these tests and NFP?
Thank you in advance.
Andrew
Answer
Dear Andrew,
In cases of a serious medical condition, limiting sexual relations to the post-peak phase of the cycle can reduce unintended pregnancies to 1% or less. Using an ovulation predictor kit (OPK) alone has not been studied for preventing pregnancy. However, there is an NFP method based on monitoring ovarian hormones using the ClearPlan (or ClearBlue) fertility monitor that has a proven track record. It is called the Marquette Method. The ClearPlan monitor tests for both the rise in estradiol and the LH peak. The rise in estradiol can occur one to five or more days before the LH peak. When the ClearPlan monitor is used, it will mark the day of the LH peak and the day after the LH peak, and mark both of these days "peak" fertility days with an egg symbol.
In the Marquette method, cervical mucus is used in conjunction with the measurements of estradiol and LH to mark the beginning and end of the fertile period. The infertile period in the post-peak phase of the cycle begins on the fourth day after the peak day. You choose the LAST peak day to calculate the infertile phase in the latter part of the cycle.This peak day will be either the SECOND peak (egg) day on the ClearPlan monitor OR the LAST day of peak-type mucus. The infertile phase of the cycle will begin on the evening of the fourth day after the peak.
To learn more about the Marquette method contact Dr. Richard Fehring at Richard.fehring@marquette.edu.
Mary L. Davenport, M.D.
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