1. Department of Obstetrics and Gynecology, Soroka University Medical Center, Ben-Gurion University of the Negev, POB 151, Beer-Sheva 84101, Israel
2. The Department of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
3. IVF Unit, Wolfson Medical Center, Affiliated to Tel-Aviv University, Tel Aviv 69978, Israel