1. Department of Obstetrics and Gynecology, Faculty of Medicine, Maranatha Christian University, Bandung, Indonesia
2. Department of Anesthesia and Intensive Care, Faculty of Medicine, Maranatha Christian University, Bandung, Indonesia
3. Department of Obstetrics and Gynecology, Prof. Dr. R. D. Kandou Hospital, Faculty of Medicine, Sam Ratulangi University, Manado, Indonesia
4. Unggul Karsa Medika Teaching Hospital, Bandung, Indonesia