Side of ovulation and cycle characteristics in normally fertile women

This study was undertaken to establish whether ovulation in humans alternat es consistently from right to left ovary in successive cycles and whether t he site of ovuIation affects the next cycle length or the hormonal profiles . A total of 199 cycles in 80 normally fertile women were studied. The volu nteers were monitored with ultrasonography to determine the day and side of ovuIation and to calculate follicular and luteal phase lengths. Urinary ho rmone concentrations were also assayed. Right-sided ovulations occurred in 104 of the 199 cycles (52.3%; not significantly different from 50%), Altern ate ovulations occurred in 61 of the 119 pairs of succeeding cycles (51.3%, not significant). The follicular phase length in contralateral ovulation ( 14.59 +/- 0.33 days; mean +/- SEM) did not differ significantly from that o f ipsilateral ovulation (14.59 +/- 0.37 days). There were also no significa nt differences in urinary concentrations of oestrone-3-glucuronide, pregnan ediol-3 alpha glucuronide, follicle stimulating hormone, and luteinizing ho rmone between ipsilateral and contralateral ovulation in either early folli cular, peri-ovulatory or luteal phase of the cycle. It is concluded that in normally fertile women, the cycle length and the hormonal profile are inde pendent of the, most probably random, site of ovuIation.