Ovulation test kits, used to track when getting pregnant is more likely, may not be as reliable if you have polycystic ovary syndrome (PCOS). This is because the hormones used to track fertility often do not spike before ovulation as they would in women without PCOS; instead, they might rise and fall erratically or remain at a constantly high level.
Because of this, urine-based ovulation tests used to track luteinizing hormone (LH) and saliva-based tests used to track estrogen may not be as reliable. To get a more accurate result, additional methods may be needed to predict when are most likely to achieve pregnancy.
A Note on Gender and Sex Terminology
PCOS affects people with ovaries, who are typically assigned female at birth. Verywell Health acknowledges thatsex and genderare related concepts, but they are not the same. To accurately reflect our sources, this article uses terms like "female," "male," "women," and "men" as the sources use them.
How PCOS Affects Ovulation and Fertility
Polycystic ovary syndrome is characterized by the formation of fluid-filled cysts on the surface of the ovaries, which can undermine their function. It is the most common endocrine (hormone-related) disorder in females, affecting one of every 20 women in the U.S. to different degrees.
The primary function of the ovaries is to produce eggs and regulate hormones for menstruation and pregnancy. When the ovaries are overwhelmed with cysts, they can start to produce erratic amounts of LH and estrogen as well as excessively high amounts of the male hormone testosterone, causing symptoms like:
- Irregular, very heavy, or very light periods
- Difficulty getting pregnancy
- Pelvic pain
- Acne
- Abnormal facial and body hair
- Male-pattern hair loss
Because women females with PCOS do not ovulate regularly, rates of infertility are high, hovering between 70% and 80%. With treatment—including the use of the drug Clomid (clomiphene)—80% of these women can achieve pregnancy, often within six period cycles.
Even so, predicting ovulation in women with PCOS remains a challenge even if the likelihood of pregnancy is increased.
PCOS And Ovulation Test Accuracy
Ovulation tests detect changes in hormones that typically spike in advance of ovulation. These spikes can tell you when is the best time to have sexual intercourse to achieve pregnancy.
There are two types of home tests licensed for use by the U.S. Food and Drug Administration (FDA):
- Urine dipstick tests: These are the most commonly used tests that detect LH levels in urine. LH levels will spike anywhere between 24 and 36 hours before you ovulate. In people without PCOS, these tests can reliably detect LH spikes nine times out of 10 times if used correctly.
- Saliva-based tests: These tests detect levels of estrogen in saliva. Estrogen levels start to surge three days or more before you ovulate. Comparatively, these tests fall beneath the detection level of urine tests, and some experts advise against their use even in women without PCOS.
Urine dipstick tests—the preferred method of home ovulation testing—have a low false-positivity rate (meaning that a positive test result is almost invariably correct).
The same may not be true for people with PCOS. In these women, LH levels may be consistently elevated or erratic, leading to an increased risk of false-positive and false-negative results.
Causes of False Positives and False Negatives
According to a 2023 study in the Journal of Medicine and Life, women with PCOS had an average LH level outside of the ovulatory period of 12.22 IU/mL compared to women without PCO who had average LH levels of 2.35 IU/mL.
During and prior to ovulation, LH levels in women with PCOS will often remain elevated above the threshold at which a positive test result is returned. This can lead to a false-positive result in which you think you are about to ovulate even though you are not. The same might even be seen when PCOS causes anovulation (the complete lack of ovulation).
In other women with PCOS, LH levels will often pulse, rising and falling erratically. In such a case, you might detect an incidental drop in your LH and presume that you are not approaching a fertile period. This is a false-negative result.
What You Can Do
If you have PCOS and are trying to get pregnant, you are more likely to do so if you use multiple methods for prediction.
Start by testing your urine daily with a urine dipstick test 10 to 14 days after starting your period. This is the window leading up to ovulation in most women.
In addition to urine testing, incorporate the following traditional means of prediction:
- Check your cervical mucus, which will become more watery and slippery before ovulation.
- Monitor the position of your cervix, which will be high, soft, and open on fertile days and low, firm, and closed on non-fertile days.
- Track your basal body temperature, which tends to rise two or three days before ovulation.
Special thermometers and apps are available to help with ovulation tracking. Some of the most popular apps include Kindara, Fertility Friend, Ovia, Glow, Flo, and Clue.
If you are unable to achieve pregnancy despite trying for six or seven months, see a fertility specialist who can help you explore different methods of fertility assistance.
Summary
Home ovulation tests may not be as reliable in predicting fertile periods in women with PCOS because the hormones tracked by these tests (luteinizing hormone and estrogen) may be consistently elevated or rise and fall erratically.
To improve your chances of pregnancy, take a urine-based ovulation test daily starting 10 to 14 days after the start of your period. At the same time, use traditional means of ovulation prediction, checking for changes in your cervical mucus, cervical position, and basal temperature. Together, these methods may help you better predict your fertile window.
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Nicole Galan, RN
Nicole Galan, RN, is a registered nurse and the author of "The Everything Fertility Book."
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