Corpus luteum across the first trimester: size and laterality as observed by ultrasound

Katrina Rowan, Simon Meagher, Mark Teoh, Beverley Janine Vollenhoven, Shawn Choong, Stephen Tong

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12 Citations (Scopus)


OBJECTIVE: To study the site and size of the corpus luteum (CL) across the first trimester of pregnancy. DESIGN: Retrospective observational study of 1,806 ultrasound scans performed at 5 to 9 (+6 d) weeks gestation, as well as a prospective study (n = 313) performed at 10 to 13 (+6 d) weeks gestation. SETTING: Four ultrasound practices across Victoria, Australia. PATIENT(S): Two thousand one hundred nineteen pregnant women. INTERVENTION(S): Transvaginal ultrasound. MAIN OUTCOME MEASURE(S): Side and size (diameter) of the CL. RESULT(S): At 5 to 9 weeks gestation, the mean CL diameter was 19.3 mm, with no statistically significant variation across each gestational week. Corpus luteum size then statistically significantly declined at 10 to 13 weeks gestation, with a mean diameter of 16.85 mm. Of 237 women in whom both ovaries were visualized at 10 to 13 weeks gestation, a CL was seen in 82 of cases. A statistically significant right-sided bias was observed in both groups (54 at 5-9 wk gestation, 56 at 10-13 wk). CONCLUSION(S): The CL remains static in size across 5 to 9 weeks gestation, then its size declines or it disappears from 10 to 13 weeks. A novel right-sided ovulation bias occurs in human beings.
Original languageEnglish
Pages (from-to)1844 - 1847
Number of pages3
JournalFertility and Sterility
Publication statusPublished - 2008

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