Home Ovulation tests: How they work and when to use them

What are ovulation tests?

Home ovulation tests are urine tests for Luteinizing hormone (LH). There are digital tests, as well as test strips. There are other methods that people use to track ovulation. These include tracking basal body temperature or checking cervical mucus and cervical position. However, using a home ovulation urine test is the most accurate of these methods. A study by K. Gudgeon et al found that in 82%-88% of cases the home test for urinary LH predicted ovulation within one day and in 89%-96% of cases within two days of the serum LH surge. 

What is LH?

Both men and women produce LH, but the amounts and purpose of this hormone are different. In women, LH is released in the second part of the menstrual cycle. LH is present at low levels during the period and in the days after, but around the middle of the cycle there is a surge in LH. This surge in LH causes release of an egg from the ovary. In other words, the LH surge causes ovulation to occur. LH also causes the ovary to secrete progesterone, which is needed during early pregnancy.

When should I start to test for ovulation?

Most home ovulation tests will give a time frame for when to begin testing for ovulation. Until you get to know your cycle, or if you have irregular cycles, you will have to test sooner. I used these ovulation test strips from Easy@Home and they were easy to use. The instructions with these test strips are detailed, providing a chart for which day of your menstrual cycle to start testing based on the normal length of your menstrual cycle. If your cycles are abnormal or you don’t know the length of your cycles, you should start testing on day 5. LH tests should be taken in the afternoon or evening. Even when testing twice daily, you shouldn’t do an LH test before 10am.

The Easy@Home ovulation test strips work well with the Premom app (I used the free version), if you like to have an app to help with tracking. I like using the Premom app because it is free and it records the LH level from the test strips for me. I will say that I have found the Premom app to be very inaccurate at predicting ovulation. The chart of LH levels is easy to read though, so with a very basic understanding of LH levels you will be able to easily see when to expect ovulation on your own.

Timing of trying to conceive (TTC) and ovulation

Ovulation occurs approximately 10-12 hours after the LH peak per the article by Reed et al cited below, but the LH peak is unlikely to be determined precisely by home ovulation tests. For this reason, it is better to keep a wider time frame in mind. From the start of the LH surge it will be roughly 36 hours until ovulation occurs. So, when you see an elevated LH level over 1 or 2 tests, then you can assume that ovulation will be in the next day or two.

When trying to conceive, there is what is called a fertile window. Having sex anytime during the fertile window could lead to a pregnancy. If you are new to TTC, you may be surprised to learn that the fertile window actually begins about 6 days before predicted ovulation. That is because sperm can live inside the woman’s body for up to 5 days, and ovulation dates as predicted by LH tests at home are accurate only to within 1-2 days.

Should I be using ovulation testing to help conceive?

The answer is, it depends. The evidence is mixed, so we’ll take a look together so that you can make the best decision for you. Personally, there have been times when ovulation testing was just what I needed. When my periods were very irregular after miscarriage, LH tests were able to help my provider and me to identify my luteal phase defect. At other times, after experiencing multiple miscarriages, ovulation testing was a part of my out-of-control anxiety. Backing off and taking a break from any form of testing or tracking helped me to put everything back in focus and stop the obsession.

I guess that what I’m trying to say is that, if you want to try ovulation testing, do it! If it comes to a point where you or your spouse are feeling stressed or unhappy about it, then stop! Whatever you decide, you can change your mind at any time. Tests are relatively cheap, so there is very little lost if you decide you want to stop testing.

What are the Benefits of ovulation testing

Ovulation testing can help you determine the best timing of sex when trying to conceive.

This is, after all, the main reason that many people use ovulation testing. With ovulation testing, you will be able to get a better idea when your fertile window is each month. This is especially useful if you have irregular menstrual cycles.

Ovulation testing can help with dating of a pregnancy

If you have been using ovulation testing, that can help with estimating due date for pregnancy. A due date is usually first estimated based on the first day of your last menstrual period, and later adjusted based on early ultrasounds. But what if you ovulate later in your cycle than on day 14? Or maybe implantation took longer to occur? When you get an early ultrasound, it could appear that your baby is behind on growth which could cause some anxiety. If you have been tracking ovulation, and know that your ovulation occurred later than day 14 or 15, you and your provider will know to expect that the baby will appear smaller on the ultrasound. 

Better dating for pregnancy for those with missed periods or irregular periods

If you are having irregular menstrual cycles or frequently missing periods, knowing when you ovulated can allow for a better estimated due date.

Testing LH levels may help provide information about cause of irregular periods

The first half of the menstrual cycle, before ovulation, is called the follicular phase. The second half of the menstrual cycle is called the luteal phase. A luteal phase deficiency occurs when the luteal phase is shorter than it should be. Normal luteal phase is 14 days, with a normal range of 11-17 days. If the luteal phase is shorter than 10 days, then that is considered a luteal phase deficiency. Multiple conditions could be the cause of luteal phase deficiency, but luteal phase deficiency has been associated with infertility, miscarriage, and short menstrual cycles.

Monitoring the LH surge with a home ovulation test can help identify when the luteal phase is beginning. Tracking the time from then until a period starts can give an idea of the length of the luteal phase. Using at-home ovulation tests helped my provider and me to determine that I was experiencing a luteal phase deficiency, leading to further testing and treatment.

Ovulation testing can lead to a better understanding of the menstrual cycle

Jones et al completed a study where women were interviewed following participation in a randomized control trial for home ovulation tests. Women reported that one of the benefits was a better understanding of the menstrual cycle. Having this information decreased some of their feelings of uncertainty. That sounds pretty good to me!

The cons of home ovulation testing

Added stress while trying to conceive

In regards to stress, the evidence and my personal experience are in opposition, so we’ll discuss both. For me personally, after my 3rd miscarriage, it seemed that all the testing was overwhelming and causing anxiety. Each ovulation test, pregnancy test, hCG test, or ultrasound was another cause for worry. I was obsessing over the process. For a time, I needed a step back to just focus on living and not on TTC. I have heard from other women with a similar experience. If you are having sex regularly, how important is it to really know exactly when you ovulate? For me, i decided my peace of mind was more important.

Now, for the evidence. I looked at 3 studies that tackled this topic of stress during TTC using ovulation tests. Women in all 3 of these studies reported negative experiences, emotion, or stress while using home ovulation tests. But, they also experienced negative feelings and stress in the control group who were TTC without ovulation testing. Two of these studies even measured urinary cortisol levels, which is a marker of stress levels. There was no difference between groups. So per the evidence, there is NO increased stress from using home ovulation tests.

Ovulation testing only slightly increased the chance of becoming pregnant when TTC

You would think that knowing when the fertile window is would help you become pregnant faster. In two randomized control trials, no difference in time to pregnancy was found when using ovulation tests vs no testing. Another study I read only followed women for 2 cycles. In the group who used ovulation tests, 36.2% became pregnant. In the control group who didn’t use ovulation tests, 28.6% became pregnant. That is a meaningful difference, and ovulation testing could help you get pregnant faster. But it’s not a magic solution to get pregnant immediately.

False positive ovulation tests

It is possible to get a positive LH surge on home ovulation tests and not actually ovulate. If you don’t ovulate, you won’t be getting pregnant. Some conditions that could cause this would be polycystic ovaries, premature ovarian failure, or perimenopause. If you are using other methods to look for ovulation, like BBT, you may be able to catch this. You might see that no change in your temperatures occur after your LH surge. If you notice this, contact your doctor and let them know what you are experiencing

Home ovulation tests can also show an LH surge when you are pregnant or have recently experienced a pregnancy loss. LH and hCG are very similar chemically, so an elevated hCG level can cause a home ovulation test to falsely show elevated LH levels. hCG is elevated during pregnancy. If you think that it is possible that you could be pregnant, and you aren’t sure when to start testing for pregnancy, read more about pregnancy testing here. hCG also remains elevated for a time after a pregnancy loss, slowly returning to normal. If you have recently had a pregnancy loss, make sure that your hCG has returned to normal before beginning ovulation testing. 

Citations

1. Gudgeon K, Leader L, Howard B. Evaluation of the accuracy of the home ovulation detection kit, Clearplan, at predicting ovulation. Med J Aust. 1990 Apr 2;152(7):344, 346, 349. doi: 10.5694/j.1326-5377.1990.tb125181.x. PMID: 2093801.
2. Reed BG, Carr BR. The Normal Menstrual Cycle and the Control of Ovulation. [Updated 2018 Aug 5]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279054/
3. Wilcox AJ, Weinberg CR, Baird DD. Timing of sexual intercourse in relation to ovulation. Effects on the probability of conception, survival of the pregnancy, and sex of the baby. N Engl J Med. 1995 Dec 7;333(23):1517-21. doi: 10.1056/NEJM199512073332301. PMID: 7477165.
4. Yeh PT, Kennedy CE, Van der Poel S, Matsaseng T, Bernard L, Narasimhan M. Should home-based ovulation predictor kits be offered as an additional approach for fertility management for women and couples desiring pregnancy? A systematic review and meta-analysis. BMJ Glob Health. 2019 Apr 25;4(2):e001403. doi: 10.1136/bmjgh-2019-001403. PMID: 31139458; PMCID: PMC6509595.
5. https://www.asrm.org/practice-guidance/practice-committee-documents/diagnosis-and-treatment-of-luteal-phase-deciency-a-committee-opinion-2021/
6. Jones G, Carlton J, Weddell S, Johnson S, Ledger WL. Women’s experiences of ovulation testing: a qualitative analysis. Reprod Health. 2015 Dec 21;12:116. doi: 10.1186/s12978-015-0103-y. PMID: 26689590; PMCID: PMC4687078.
7. Weddell S, Jones GL, Duffy S, Hogg C, Johnson S, Ledger W. Home ovulation test use and stress during subfertility evaluation: Subarm of a randomized controlled trial. Womens Health (Lond). 2019 Jan-Dec;15:1745506519838363. doi: 10.1177/1745506519838363. PMID: 30924413; PMCID: PMC6444416.
8. Tiplady S, Jones G, Campbell M, Johnson S, Ledger W. Home ovulation tests and stress in women trying to conceive: a randomized controlled trial. Hum Reprod. 2013 Jan;28(1):138-51. doi: 10.1093/humrep/des372. Epub 2012 Oct 18. PMID: 23081872; PMCID: PMC3522415.
9. Johnson S, Stanford JB, Warren G, Bond S, Bench-Capon S, Zinaman MJ. Increased Likelihood of Pregnancy Using an App-Connected Ovulation Test System: A Randomized Controlled Trial. J Womens Health (Larchmt). 2020 Jan;29(1):84-90. doi: 10.1089/jwh.2019.7850. Epub 2019 Sep 4. PMID: 31483187; PMCID: PMC6983750.