1. Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City, Philippines.
2. Department of General Surgery, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines.
3. Department of Obstetrics and Gynecology, Philippine General Hospital, University of the Philippines Manila, Manila, Philippines.
4. Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, California, USA.