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Four reasons why I NEVER recommend ovulation predictor kits (OPKs)!

Four reasons why I NEVER recommend ovulation predictor kits (OPKs)!

By Kate Davies, RN, BSc(Hons), FP Cert - Fertility Nurse

Have you ever used ovulation predictor kits (OPK’s) or an ovulation prediction monitor (OPM) to predict when you ovulate? Have you had a good or bad experience of using OPK’s? I am very sceptical of the reliability of this ovulation prediction method and as a result, I don’t recommend them to any of my patients. Here’s why……….

1. Inaccurate

OPK’s (sometimes referred to as LH kits) are used to detect the rise of the ovulation hormone, luteinising hormone (LH) 24-36 hours prior to ovulation. LH is the hormone that triggers the release of an egg from the ovary and after the hormone surge ovulation usually occurs 24-36 hours later.

Not every woman is able to use OPK’s however. If you have Polycystic Ovaries (PCO) or Polycystic Ovarian Syndrome (PCOS) you are likely to have high levels of LH at other times of the month and this produces 'false positives' leading to confusion over when to try and get pregnant (McGovern and Myers 2004).

However, even in women without PCO or PCOS it is widely documented in the clinical literature that OPK’s can produce ‘false negative’ results meaning that you get no indication of ovulation even though you are about to ovulate (Arici et al. 1992; Irons et al. 1994 and Lloyd et al. 1989).

 2. Inconvenient and Confusing

Some manufactures of OPK’s suggest that you test first thing in the morning as this is more convenient time and you are likely to have held your urine for the required 4 hours prior to testing. However others suggest that the first sample in the morning is not sufficient, as the LH surge is very likely not to be present in urine until later in the day. Therefore suggesting that the optimum time to test is late morning or early afternoon. Imagine trying to do this when you are busy at work and how easy it would be to not be able to test at the same time every day. In a 24 hour period it is very easy to miss the LH surge and therefore get inaccurate results that may completely miss ovulation. My patients report that this is just another stress in their fertility journey that they would prefer to avoid.

3. Stressful

I find many women become all consumed by testing their urine and this in turn puts pressure on the their intimate relationship with their partner. Sex becomes much more about baby making than it does about being close and loving with one another.

4. Expensive

Unfortunately the cost of OPK’s used every month really adds up. Add to this the inaccurate results and you are pouring money down the drain. There are other ways that you can accurately predict ovulation that are a great deal more cost effective. Observing your temperature and your cervical secretions is a very effective way of determining your fertile time and when you ovulate. Combine this with regular sex every 2-3 days throughout the cycle and you will be optimising your chances of conceiving quickly and naturally.


Arici A, Carr BR (1992) Comparison of two LH monitoring methods in women undergoing intrauterine insemination. Proceedings of the 48th Annual Meeting of the American Fertility Society.

Irons DW, Singh M (1994) Evaluation of transvaginal sonography combined with a urinary luteinizing hormone monitor in timing donor insemination. Hum Rep 9:1859-62.

Lloyd R, Coulman CB (1989) The accuracy of urinary luteinising hormone testing in predicting ovulation. Am J Obstet Gynecol, 60:1370-2.

McGovern PG, Myers ER (2004) Absence of secretory endometrium after false-positive home urine luteinizing hormone testing. Fertil Steril 82:5.

A note from OvuSense: OPK tests and monitors sometimes indicate ovulation when none has occurred, and miss some ovulation events altogether. Couples who use them could be attempting to conceive at the wrong time. In addition, using these kits correctly means remembering to test 2-3 times a day, at similar times, consistently. OvuSense can tell you when you are about to ovulate just like an OPK test or monitor and it does this with a positive predictive value of 96% [a, 1], and unlike an OPK it then confirms the exact day of ovulation with 99% accuracy, giving you confidence and putting you in control of your fertility. [b, 1]
Additionally, OvuSense is the only fertility monitor on the market which will tell you if you haven’t ovulated (also very important), and remote fertility screening and monitoring of your medication and treatments by your doctor (using OvuSense Pro). [2]

[a] The positive predictive value measures how many of the real time predicted ovulations OvuSense gets right.

[b] The accuracy measures how many positive and absent ovulations the device confirms correctly.

[1] The accuracy of ovulation confirmation by OvuSense is based on the data set originally published at the 2013 ASRM meeting as a quality index: Papaioannou S, Aslam M (2013) , and developed in the key publication outlining the accuracy and positive predictive value of advance prediction of ovulation shown at the 2014 ESHRE meeting: Papaioannou S, Delkos D, Pardey J (2014).

[2] The analysis of cycle patterns which led to the development of the OvuSense Pro product:

Hurst BS, Karoshi M (2020) Atypical Core Body Temperature patterns and the wider implications for conditions related to pregnancy, infertility, and miscarriage risk P-833 American Society for Reproductive Medicine 76th Annual conference. Poster
Fertility and Sterility - September 2020 Volume 114, Issue 3, Supplement, Pages e446–e447 |

Hurst BS, Pirrie A (2019) Atypical vaginal temperature patterns may identify subtle not yet recognised causes of infertility P-345 American Society for Reproductive Medicine 75th Annual conference.;, Fertility and Sterility - September 2019 Volume 112, Issue 3, Supplement, Pages e244–e245;

If you are an OvuSense customer with an annual subscription you are entitled to a FREE 1 hour consult. Consultations are held by Skype or Telephone. Book your FREE consultation with the OvuSense Fertility Nurse, Kate -  to assess your fertility potential, answer your burning fertility questions, get recommendations on how to optimize your fertility and have your charts analysed.

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Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition.

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