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

Abstract

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 ..