Ovulation predictor kits (OPKs) or ovulation tests can help women identify when their fertile window is going to take place. However, there is no scientific evidence that using them can actually increase your chances of conceiving.
Urine-based OPKS work by testing a small sample of urine fora surge in LH levels, which normally occurs 1-2 days before ovulation. These tests are about 99 per cent accurate and are probably the best method for predicting ovulation.
Three possible results can appear (C = Control; T = Test):
- LH surge. If the T band is equal to or darker than the C band, ovulation is about to take place within the next 24 to 48 hours.
- No LH surge. If the color band appears on the C region, or the T band is lighter than the C band, there is no LH surge.
- No visible band. It appears when an insufficient volume of urine is added into the test kit.