[Risk factor scoring model of STD for pregnant women in antenatal clinic]

To develop a case finding strategy for STD among pregnant women based on risk assessment in China.

A prospective, random/double blind study of the high risk factors for STD in 1,656 pregnant women was conducted from June 1995 to February 1996. It was carried out at four Guangzhou hospitals on nine types of STD, their relative risk factor questionnaire and gynecologic examination.

The total prevalence of six main STD was 20.89% (346/1656); No HIV and syphilis cases were found; The most common disease is cervical chlamydial trachomatis at (19.08% 316/1,656). Through statistical calculations with COX proportional hazard model, STD symptoms' high risk factors scoring system revealed the following: (1) More than one sexual partner in the preceding one year; (2) Vulvular lesion vegetation; (3) Dysusia/increased vaginal discharge; plus one of the following: 1. unemployed status; 2. sex partner unemployed; 3. age (less than 25 years of between 30-34 years of age). These six items with "three-three" scoring system can be used as a model to primary screening new STD cases using clinical data. Both sensitivity and specificity exceeded 60% (61.7% and 67.3% respectively).

These are significantly better than the foreign recommended model and the scoring system in China. It is simple, convenient and applicable.