DOES CORPUS-LUTEUM LOCALLY AFFECT FOLLICULAR-GROWTH NEGATIVELY

In this study bilateral ovarian follicular growth during the luteal ph ase was investigated in relation to the ovary where ovulation occurred , The diameter of the largest follicle in the contralateral ovary with out corpus luteum and in the ipsilateral ovary with corpus luteum was measured using vaginosonography in a total of 66 natural cycles of 27 normally cycling women undergoing treatment with intrauterine insemina tion (IUI). None of the women received ovarian stimulation or luteal s upport, Follicles from 2 to 11 mm in diameter were measured in early l uteal phase (day +1 to +4), mid-luteal phase (day +5 to +9) and late l uteal phase (day +10 onwards), The mean diameters of the largest folli cle in the contralateral ovary without corpus luteum during the early, mid- and late luteal phases were 6.81 +/- 1.33 (mean +/- SD), 6.14 +/ - 1.29 and 5.71 +/- 1.17 mm respectively, while those of the ipsilater al ovary with corpus luteum were 6.48 +/- 1.40, 5.65 +/- 1.47 and 4.98 +/- 1.19 mm respectively, While there was no significant difference d uring the early luteal phase, the mean diameter of the largest follicl e in the ipsilateral ovary with corpus luteum was significantly smalle r than that of the contralateral ovary without corpus luteum during th e mid-luteal phase (P < 0.004) and the late luteal phase (P < 0.0005). These results indicate that the corpus luteum locally affects neighbo uring follicular growth negatively during the luteal phase of the mens trual cycle, with the most pronounced effect expressed in the mid- and late luteal phases.