BACKGROUNDThis is a prospective clinical study based on a large sample gathered from multiple centers in China, subordinating to 10th Five-Year Plan of National Science & Technology Progression. We analyzed the high-risk factors inducing hypertensive disorders in pregnancy (HDP) and estimated the potential effect of anti-oxidants administration, including vitamin C (VC), vitamin E (VE) and Salvia Miltiorrhiza L (SML), a Chinese herb medicine, in amelioration of the high-risk factors in pregnancy.

METHODSFrom April 2005 to July 2006, 4814 pregnant women from 24 national wide cooperative hospitals were involved in this prospective research. The participants were randomly divided into two groups: 1607 cases were in anti-oxidants group with administration of vitamins and SML; 3207 cases were in control group without any medicine given. Every participant was under monitoring for the morbidity of HDP and the high-risk factors were investigated in HDP cases in each group.

RESULTS(1) The morbidity of HDP was 3.55% in anti-oxidants group vs. 4.18% in control group. No statistical difference existed between the two groups (P > 0.05). (2) In anti-oxidants group, the HDP morbidities among three subgroups: VC + VE + SML, VC + VE and SML only, were 5.51%, 3.05% and 5% respectively. It showed no statistical difference among three remedies (P > 0.05). (3) The related index of factors affecting HDP showed in intensity sequence as follows: family HDP history > profession > education level > age > body weight. The incidence of HDP in normal population was 3.51%, and the incidence of HDP in high-risk pregnant women (family HDP history, heavy physical labor, low education level (middle school and below), age ≥ 40, body mass index ≥ 24) was 5.84%, which was obviously higher than that in normal population (P < 0.01). In anti-oxidants group, the probability of HDP in women with high-risk factors was 3.81%, which was obviously lower than that in control group with high-risk factors at 7.14% (P < 0.01). (4) In control group, the morbidity of HDP in women with family HDP history (especially with sisters'), heavy physical labor, middle school and below, age ≥ 35 was: 50.00%, 15.22%, 6.33%, 26.28% and 5.75%, respectively, and that in anti-oxidants group was 0, 7.69%, 3.74%, 9.27% and 2.67%, respectively, which was obviously lower than that in control group.

CONCLUSIONSThe high-risk factors prone to induce HDP included: family history of HDP, heavy physical labor, low education level, aging and obesity. No impressive effect of anti-oxidants application was found in preventing HDP in general population but the remedy demonstrated positive effect on preventing HDP in pregnant women with high-risk factors.