Jet Travel and the Ovulation Calendar Predictor

Couples who use the rhythm method of family planning need to be aware that daytime flights across the ocean can accelerate ovulation.

Ovulation is stimulated by the release of a surge of luteinizing hormone (LH) from the pituitary gland in the brain. Typically, this dramatic dump of LH occurs in late afternoon.

Although ethical concerns prevent clinical trials on humans, studies of animals suggest that a sudden shift to a longer day (either traveling to the North or South Pole in summer or traveling in daylight across the ocean) can cause the massive release of LH that might cause the release of the egg a day or two earlier than expected. Normal ovulation typically is restored the next menstrual cycle.