Cross-over design trials in infertility: How much multiplicity is too much?

To the Editor:

We read with interest the article by Francavilla et al. published in the recent issue of the Journal (1). The authors set out to “analyze the effectiveness of intrauterine insemination with or without mild ovarian stimulation in male subfertility using a prospective cross-over design.”

Risk of birth defects increased in pregnancies conceived by AHR

To the Editor:

In a recent publication, using the Niday Perinatal Database from 82 primary and tertiary centers in Ontario for 2005, El-Chaar et al found that assisted human reproduction (AHR) procedures increase the risk of birth defects in a retrospective cohort design (1).