Ultrasound: a technique useful in determining the side of ovulation

It is often assumed that ovulation commonly occurs from alternating sides each month, but it is unknown whether it can occur repeatedly from the same side. In an effort to answer this question, we selected 39 women from our infertility clinic who had six consecutive courses of ultrasound (US) to monitor ovulation and in whom the side of ovulation was recorded. Nine patients (23.1%) ovulated from the same side for six consecutive cycles, whereas no patient alternated side of ovulation in the same period of time. Stimulation with clomiphene citrate and/or human menopausal gonadotropin that results in single ovulation did not affect this pattern. The data were analyzed statistically with the use of a Markov Chain Model and the chi-square goodness-of-fit; the occurrence of persistent same-side ovulation was significant to P less than or equal to 0.001.