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.