Uterine contractility and directed sperm transport assessed by hysterosalpingoscintigraphy (HSSG) and intrauterine pressure (IUP) measurement

Background.  Uterine peristalsis sustains sperm transport and can be detected by hysterosalpingoscintigraphy (HSSG). This study is the first to be designed to investigate utero‐tubal transport function by HSSG and uterine contractility by intrauterine pressure measurement (IUP) consecutively on the same day in the periovulatory phase.Methods.  Twenty‐one female subjects (mean age 28.4 years) without a gynecologic history were examined sequentially by HSSG and IUP on the same day to evaluate uterine contractility in relation to the utero‐tubal transport function. In HSSG, intact transport function was visualized by the rapid uptake of 99m‐technetium‐marked albumin aggregates through the female genital tract. In IUP, the frequency of uterine contractions (UC/min), amplitude of uterine contractions and basal pressure tone were detected via a intrauterine catheter. HSSG and IUP were embedded in cycle monitoring with measurement of LH and estradiol.Results.  In HSSG, a positive transport of inert particles was assessed in 20 of 21 subjects, in 76% to the side of the dominant follicle or on both sides of the oviduct, and in 19% a strict contralateral transport could be observed. In only one subject (5%), no transport was assessed. The mean value of uterine contractions was 3.4 UC/min (SD ± 0.7), the mean amplitude was 12.0 mmHg (SD ± 4.25 mmHg). Basal pressure tone was 70.7 mmHg. There was a statistically significant correlation with estradiol levels: none of the subjects with less than 3 UC/min showed an estradiol level higher than 100 pg/mL; nearly every patient (one exception) with more than 3 UC/min had an estradiol level higher than 100 pg/mL (p < 0.0001, Fisher's exact test).Conclusions.  Intact periovulatory utero‐tubal transport function can be documented by HSSG and is caused by directed uterine contractility, measured consecutively by IUP. Uterine contractility is influenced by rising estradiol levels. Directed uterine contractility and intact utero‐tubal transport function are considered necessary for intact sperm transport, mainly to the side bearing the dominant follicle to maximize fertility.