1. Department of Environmental Medicine, Kochi Medical School, Kochi University, Kochi, Japan
2. Department of Obstetrics, Kochi Health Sciences Center, Kochi, Japan
3. Department of Pediatrics, Kochi Medical School, Kochi University, Kochi, Japan
4. Department of Obstetrics and Gynecology, Kochi Medical School, Kochi University, Kochi, Japan