From the University of Singapore, Department of Obstetrics and Gynaecology; Kandang Kerbau Hospital for Women, Singapore; and the University of California International Center for Medical Research and Training, the George Williams Hooper Foundation (San Francisco-Singapore), San Francisco, Calif.

Supported by the University of California International Center for Medical Research and Training (Hooper Foundation, San Francisco School of Medicine) with Research Grant GM 11329 from the Office of International Research, National Institutes of Health, U. S. Public Health Service.

I would like to thank the following for their kind assistance: the Staff of Bacteriology, Government Department of Pathology, General Hospital, Singapore; and Dr. Thomas Ng Khoon Fong, M.B.B.S., M.R.C.O.G., General Hospital, Johore Bahru, Johore, Malaysia.

^* Present address: University of Colorado Medical Center, Denver, Colo.