At that enrollment level, the study would aim to show a 50% reduction in late miscarriages and preterm birth, with a power of 85%. Two predetermined analysis were planned at the end of the 3-year study, one for the intent-to-treat population and one for the per-protocol group.
In the end, however, just 487 patients were enrolled and randomized over a period of 5 years, despite recruitment at 14 centers in Iceland, Norway, and Sweden.
Richard Legro, MD, an ob.gyn. from Pennsylvania State University, Hershey, was in attendance. While praising the overall high quality of the study, he commented, “The primary concern is that you stopped the study when you hadn’t even achieved half your sample size.”
Dr. Løvvik said that a variety of factors contributed to the low study enrollment. One primary issue was that participation required additional visits on the part of participants; the study was not part of routine prenatal care, she said. Also, the placebo used in the study expired before enrollment was completed, complicating execution of the study.