Fertility Chronicles is proud to present a special blog series, “From the Fertility Experts,” where leading fertility experts answer commonly asked questions for patients about their fertility health and treatment options. We hope this series can help patients navigate their personal fertility journeys.—Catherine T. Yang, Editor, Fertility Chronicles
Guest blogger and Infertility Specialist Dr. Sunny Jun of the Palo Alto Medical Foundation shares her advice
In order to conceive, a woman must ovulate; that is, an egg must be released. And knowing when that happens is crucial. To get pregnant, you need to have sex around the time of ovulation. Your most fertile days are one to two days before ovulation and on the day of ovulation. The reason? The egg can survive for up to 24 hours after leaving the ovary, but sperm can live for three to five days. So it makes sense for the sperm to reach the fallopian tube – where fertilization occurs -- before the egg does.
To start, you’ll need to know the length of your menstrual cycles. The length of your cycle is the number of days between the first day of full flow and the first day of your next full flow. Spotting or very light bleeding should not be counted as the first day of your period.
For women with 28-day cycles, ovulation usually occurs around day 14 plus or minus one to two days. If your cycle ranges between 27 to 34 days, you will normally ovulate between days 13 to 20. You can make these calculations yourself, but some people use ovulation predictors on the Internet or mobile apps, in which you enter the starting dates of your last several periods. However, you should confirm it with an ovulation prediction kit (OPK) that you can purchase online or from a drug store.
Many women take basal body temperatures (BBT) which is considered to be much less accurate than using an OPK, because many factors can affect your BBT. For example, irregular sleep-wake hours, drinking coffee at night, or unusual stress can throw off your BBT. Also, when your BBT rises to signal ovulation, ovulation may have occurred already, and you will have missed the most fertile one to two days prior to ovulation.
OPKs, which cost from $20 to $50, use test strips that test your urine for levels of luteinizing hormone, or LH. Sometimes the first urine can give false positive results if the urine is too concentrated. Testing is recommended with the second urine of the morning. Checking it once daily is more than enough. When LH surges, a woman usually ovulates within 12 to 36 hours of the surge. You should begin testing two to three days before the day you expect to ovulate and continue until the test indicates that you are on the verge of ovulating. If your cycle is irregular, try beginning testing on day 11, just to be safe. The best time to have intercourse: Two to three days prior to ovulation, day of positive OPK and the day after the positive OPK.
If you don’t have regular menstrual cycles, or you’ve used the kit during two menstrual cycles and there is no indication that you are ovulating, it may be time to see a fertility specialist. A small percentage of women have a form of LH that is not detected by the kit, but a fertility specialist would be able to order other tests to figure out whether you are ovulating regularly.
Visit Trying To Get Pregnant for more fertility health information and interactive tools to personalize your fertility path.
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