A randomized controlled clinical trial of 2295 ultrasound-guided embryo transfers.

Background: We wanted to test the hypothesis that using abdominal ultrasound at the time of embryo transfer to guide replacement, improved pregnancy rates by at least 5%.

Methods: An RCT in a large assisted conception unit. A pilot study and power calculation suggested that at least 2000 embryo transfers were required to demonstrate a difference of 5%, for a test with 80% power and Type 1 error 0.

A potential new use for gonadotropin-releasing hormone antagonists.

Objective: To describe a potential new use of gonadotropin-releasing hormone (GnRH) antagonists.

Design: Case report.

Setting: Assisted conception unit at a teaching hospital in the United Kingdom.