4D ultrasound a promising tool in evaluation of uterine contractility

Four-dimensional (4D) ultrasound appears to provide a dynamic view of uterine contractions, including their directionality and frequency, and represents a promising diagnostic tool in clinical practice, a study has shown.

The study examined the utility of step-by-step 4D ultrasound assessment video to study uterine peristalsis, its relationship with progesterone levels in a select in vitro fertilization population, and the reproducibility of the technique.

A total of 197 consecutive patients undergoing in vitro fertilization with a history of recurrent implantation failure (defined as unsuccessful implantation of a total number of ≥3 blastocysts originated from oocyte donation cycles) underwent 4D ultrasound. Potential uterine factors explaining the failures in oocyte donation cycles were explored.

The contractions, which appeared like waves going through the endometrial cavity, were counted on a ×15 accelerated recording video. Overall, an average of 1.1 contractions per minute (cpm) was observed in the population.

Forty-one patients had hypercontractility (>1.51 cpm), while 156 had normal contractility (≤1.51 cpm). These groups were similar in terms of patient age and the presence of any uterine factor (adenomyosis, myomas, adhesions, or polyps).

UC showed an inverse association with progesterone levels. Participants with hypercontractility had lower progesterone levels than those with normal contractility (15.9 vs 19.5 ng/mL; p=0.027). The intraclass correlation coefficient to evaluate the interobserver variability was 0.75 (0.63–0.85; p=0.000).

Based on the findings, the researchers believe that even though recurrent implantation failure is not yet fully understood and probably associated with multiple factors, elevated uterine contractility associated with low progesterone levels may have a potential effect on the outcomes of some patients.