Objective  To examine the prevalence and risk factors of pregnancy-induced hypertension syndrome (PIH) among pregnant women living in Tongren region of Guizhou province and to provide references for taking corresponding interventions.

  Methods  We carried out a questionnaire survey, routine examination, physical examination and laboratory tests among 98 527 pregnant women 17 – 39 years selected with random sampling form Tongren region between January 2016 and September 2018. We used SAS 9.1 in data analyses.

  Results  Among all the participants, 10 591 PIH cases were identified and the prevalence and the standardized prevalence rate of PIH were 10.75% and 10.61%. The results of unconditional multivariate logistic regression analyses revealed following risk factors of PIH: aged 20 – 29 years (odds ratio OR = 2.032, 95% confidence interval 95% CI: 1.106 – 2.234) or aged 30 – 39 years (OR = 3.472, 95% CI: 1.148 – 4.159, Dong nationality (OR = 2.087, 95% CI: 1.136 – 4.568), Miao nationality (OR = 4.286, 95% CI: 1.217 – 5.396), education of primary school and below (OR = 3.368, 95% CI: 1.234 – 4.7650), being a worker (OR = 2.008, 95% CI: 1.122 – 3.156), being a farmer (OR = 4.274, 95% CI: 1.216 – 5.125), with an average annual household income of 5 000 – 8 000 RMB yuan (OR = 1.835, 95% CI: 1.125 – 2.763) and < 5 000 yuan (OR = 3.826, 95% CI: 1.138 – 4.112), current smoking (OR = 2.825, 95% CI: 1.217 – 4.128), family history of hypertension (OR = 5.075, 95% CI:1.297 – 5.526), maternal history of PIH (OR = 4.609, 95%CI: 1.218 – 5.655), gestational weeks of ≥ 35 weeks (OR = 2.409 , 95% CI: 1.116 – 3.078), delivery number of ≥ 3 (OR = 2.618, 95% CI: 1.115 – 3.437), high body mass index of being overweight (OR = 2.607, 95% CI: 1.213 – 3.035) or obesity (OR = 3.707, 95% CI: 1.216 – 5.924) before pregnancy, with a body weight gain of 12.0 – 18.0 kilograms (OR = 2.204, 95% CI: 1.125 – 3.774) or ≥ 18.1 kilograms (OR = 3.682, 95% CI: 1.139 – 4.776), stress (OR = 3.084, 95% CI: 1.162 – 3.879), low serum calcium (OR = 2.732, 95% CI: 1.125 – 3.007), low serum magnesium (OR = 2.882, 95% CI: 1.127 – 3.224); the results also showed following protective factors against PIH: normal amount (OR = 0.581, 95% CI: 0.127 – 0.904) or higher amount (OR = 0.498, 95% CI: 0.264 – 0.781) of vegetable and fruit consumption and having 6 or more prenatal examination (OR = 0.471, 95% CI: 0.275 – 0.765).

  Conclusion  The prevalence rate of pregnancy-induced hypertension syndrome is relatively high among pregnant women in Tongren region of Guizhou province and high risk factors-specific interventions on the disease need to be implemented among the women.