[Study on the descriptive epidemiology of pregnancy-induced hypertension from 1995 - 2000 in Jiaxing of Zhejiang province, China].
OBJECTIVE
To describe the epidemiological characters of pregnancy-induced hypertension (PIH) in Jiaxing areas of Zhejiang province of China between 1995 and 2000.


METHODS
We analyzed the perinatal health surveillance data that was collected as part of the Sino-American cooperative project on neural tube defects prevention established in 1992. The study population consisted of 136 070 pregnant women with at least 20 weeks of gestational age. National diagnostic criteria were used to identify the cases which were divided into three subgroups: mild, moderate and severe.


RESULTS
15 127 cases were identified and the overall incidence rate of PIH was 11.1% (95% CI : 11.0% - 11.3%). Among all the cases, mild, moderate and severe PIH were accounted for 71.4%, 22.3% and 6.3%, respectively. The proportions of PIH cases that occurred in the second trimester, third trimester and during delivery appeared to be 4.2%, 34.4% and 61.4%, respectively. There was a significant fall in the trend of PIH occurrence every year, which dropped from 10.7% in 1995 to 8.6% in 2000 by 19.6%. More risk of PIH seemed to be related to those mothers living in the urban areas with age under 20 or above 35, being peasants and having little educational, having had multiple gestations, conceiving in spring/summer or delivering in winter or spring etc. Compared with the results of national survey in 1988, the incidence rate of PIH was higher by 18.1%, while the proportion of severe PIH was much lower by 68.8%. Although the incidence rates of PIH in urban and rural areas were somehow similar, the proportion of severe PIH in rural areas was much higher than that in urban areas.


CONCLUSIONS
Overall incidence rate and distribution of PIH were reported. Compared with the results in 1988, incidence rate of PIH was much higher, particularly for mild cases.
Ma
Rui
R
Institute of Reproductive and Child Health, Peking University, Beijing 100083, China. liujm@ncmih.bjmu.edu.com
Liu
Jian-Meng
JM
Li
Song
S
Ye
Rong-Wwei
RW
Chen
Hua
H
Xue
Ming-Jun
MJ
Wang
Tai-Mei
TM
Cheng
Ling-Chun
LC
Zheng
Jun-Chi
JC
Wu
Li-Min
LM
Pan
Yu-Juan
YJ
Chen
Hao
H
Li
Zhu
Z