Predicting Ovulation and Monitoring IUI Cycles
The insemination must be timed properly to maximize the chance of pregnancy. Sperm can last for several days in the female reproductive tract, however, the egg can only be fertilized within a 24 hour period (approximate).
The level of luteinizing hormone (LH) rises in the urine 36-40 hours before the egg is released. Home ovulation predictor kits (OPKs) test the urine for LH and predict ovulation accurately 90-95% of the time. Women with PCOS often have elevated LH levels, which can cause a false positive test. The insemination is scheduled 36-40 hours after the surge.
Follow the kits instructions and begin testing before 5:00 PM on day 10 of your cycle. Cycle day one is the first day of your menstrual cycle. Testing is done once daily at approximately 11:30 AM or twice daily, early morning and evening. Ovulation will most likely occur between days twelve and twenty. When your test is positive call the office as soon as possible to schedule the IUI. If the LH level surges in the evening, call us the next morning. If you surge on a day we are closed, call our answering service at (866) 774-1266 to contact the on call physician. Call us for further instructions if you don't surge by day 18.
If the test is positive in the morning or at noon, we usually perform the IUI the next day. If it is negative in the morning and positive in the evening, we usually perform IUI the next afternoon or the following morning (1.5 days later). The menses will occur 13-15 days after the LH surge. If the menses doesn’t start, you are either pregnant or ovulation did not occur (false positive OPK test).
If the OPK testing seems inaccurate, we do a blood test for LH (should be high >30) in the next IUI cycle. We often check a blood progesterone level 7 days after the IUI to confirm that ovulation with good luteal progesterone production occurred.
Additional Cycle Monitoring
- Ultrasound to confirm the number and maturity of the follicles and the thickness of the lining of the uterus.
- Blood estradiol levels to confirm healthy mature follicles.
- Transvaginal ultrasounds, estradiol, LH and progesterone measurements are done when FSH is used. This helps avoid multiple births, FSH side effects and can determine the best time to give the hCG injection..