Timing of Ovulation: Apps Versus Urine Testing
Ovulation timing has been practiced for many years, either as a form of contraception to avoid the fertile days of the month or to help increase the possibility of pregnancy. It is now known that the egg is most healthy for less than 24 hours, while sperm can function for many days. Some methods of estimating ovulation, based on a rise of basal body temperature in the second half of the menstrual cycle after ovulation or observation of increased mucus amount and thinness just prior to ovulation, are now mostly of historical interest. Although some of my patients still try to use these very natural methods, they can miss the day of ovulation by four or more days.
The recent grafting of cell phones into our lives has blossomed over 1000 apps that purport to help in ovulation timing. At the same time, urine testing for LH has become a more accurate and less expensive option, utilizing kits that are widely available through pharmacies, grocery stores, and online.
Which of these are most useful?
How smart are these apps really?
Basically, the app averages the length of each menstrual cycle and estimates that ovulation occurs about 14, plus or minus 2, days before the subsequent period. Thus, a woman with a 26 to 30 day cycle will be presumed "fertile" from cycle days 10 to 18(counting the first day of menstrual flow as the first day of the cycle).
Advantages of using smartphone apps for tracking ovulation:
- Easy recall of menstrual periods, intercourse, and other symptom dates.
- Avoidance of urine tests, ultrasounds, and blood draws.
- More natural.
Disadvantages of using smartphone apps for tracking ovulation:
- No pinpoint accuracy, just educated guessing.
A recent article by Moglia et al (Obstet Gynecol 2016:127:1153-s60) evaluated 1116 apps. After limiting those that cost money, were not in English, or did not track the cycle, 108 remained. Of these, their investigation deemed 20 both accurate and free of charge. As noted in their article, the apps felt "most reliable" were:
Clue, Day After, FemCal Lite, Fertility Cycle, The Flow, Free Girl Cal, Glow, Groove, iPeriod Period Tracker Free, It's a Girl Thing, Lily, LoveCycles Menstrual, Ovulation and Period Tracker, Menstrual Calendar, Menstruation and Ovulation (now known as "Menstrual Period Tracker"), Mom and Baby to Be, MonthPal (now known as "Touchable Period Tracker"), Period Tracker, GP Apps, Period Tracker, Free Menstrual Calendar, Pink Pad Period and Fertility Tracker Pro.
This list should not imply an endorsement, as I have not personally reviewed or used any of these. The list is provided to help you as you research the 1000-plus options available to you to find the one that works best for you.
Because the urine testing apps just produce an estimate, more sophisticated tests are available to time ovulation.
The LH surge can now be accurately measured in urine. Physiologically, the pituitary gland releases a large amount of LH when the brain is primed with sufficient estrogen from the ovary. In this way, the follicle (egg sac) in the ovary actually controls egg release by signaling the brain when it feels it is mature enough for ovulation to occur. A massive amount of LH is produced, and ovulation (egg release) occurs within 36 to 40 hours after the initiation of the LH surge. When we measures LH in the urine, we are not necessarily picking up the onset of the surge but its first detectability. It has therefore been found that egg release generally occurs within 12 to 24 hours after the LH surge is first detected in urine. Many kits are available for this use. My preference is the simplest kit that just measures the LH surge. Some people prefer a kit that provides a single "yes", such as those with a “smiley face”, while others like to get a kit with two lines, one representing the positive control and one representing the patient’s actual urine result.
Several tips on the use of the urine ovulation predictor tests:
- We prefer to have our patient check her urine the evening, beginning abut four days before an expected positive. If the couple is seeking a baby, they then should have intercourse twice after the positive surge is detected in the urine, for example that night and the next night. These are the two "business days" of the month. Intercourse the remainder of the month should be for fun, as it will not affect the chances of being pregnant that month.
Reasons for a negative result on the LH surge kit:
- Actual absence of LH, as is seen in patients who are not ovulating.
- Malfunction of the kit.
- Positive but inadequate LH surge.
- Mistiming (for example, too early or too late).
- Urine too diluted (therefore limit water intake)
An easy way to see if ovulation has likely occurred when no LH predictor test is seen is to measure a serum progesterone level one week later. Any value over 3 ng/ml is likely consistent with ovulation.
False positives: There are also a number of false-positive LH surge tests that must be remembered, and your physician can help you in interpreting these.
- Polycystic ovarian syndrome.
- Testing the urine immediately after taking clomiphene.
- Testing the urine immediately after a GnRH agonist injection (for example, Lupron).
If you are unsuccessful in achieving pregnancy after one year of trying, consider seeing a fertility specialist at IVF FLORIDA for professional help.