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📖 LH Surge

A rapid rise in Luteinizing Hormone that triggers ovulation approximately 24-36 hours later. OPKs (ovulation predictor kits) detect this surge.

Quick Summary (LH Surge): A rapid rise in Luteinizing Hormone that triggers ovulation approximately 24-36 hours later. OPKs (ovulation predictor kits) detect this surge.

In Detail

The LH surge occurs when estrogen from the dominant follicle reaches a threshold level, signaling the pituitary gland to release a burst of LH. This surge causes the follicle to rupture and release the egg (ovulation) within 24-36 hours. OPKs detect the surge in urine — a positive test means ovulation is likely within 12-36 hours. The fertile window includes the LH surge day and the day after. Some women have a brief surge (less than 24 hours), making twice-daily OPK testing helpful.

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