ABSTRACT
<p><b>OBJECTIVE</b>To examine the relationship between prepregnancy body mass index (BMI) and the risk of pregnancy-induced hypertension (PIH) in Chinese population.</p><p><b>METHODS</b>Data were collected in 6 counties/cities covered by Perinatal Health Care Surveillance System which was part of the Sino-American cooperative project on neural tube defects prevention established in 1992. The study population consisted of 83 159 women who attended premarital or preconception medical physical examination and delivered single live births with at least 20 gestational weeks from 1995 to 2000 in Jiaxing area. The Chi-square test was employed to test the difference in the rates of PIH among groups with different BMI. Multivariate logistic regression was conducted to examine the association between prepregnancy BMI and the risk of PIH.</p><p><b>RESULTS</b>The rate of PIH was 11.01% (9153/83 159; 95% CI: 10.79% - 11.22%). The rate of PIH among women with BMI < 18.5 kg/m(2), 18.5 - 22.9 kg/m(2), 23.0 - 24.9 kg/m(2), and > or = 25.0 kg/m(2) were 9.08% (1405/15 472; 95% CI: 8.63% - 9.54%), 10.82% (6389/59 054; 95% CI: 10.57% - 11.07%), 14.63% (943/6444; 95% CI: 13.78% - 15.52%), and 19.00% (416/2189; 95% CI: 17.38% - 20.71%), respectively, the difference was significant (chi(trend)(2) = 261.028, P = 0.000). Taking those with BMI 18.5 - 22.9 kg/m(2) as reference, the unadjusted RR for PIH was 0.82 (95% CI: 0.77 - 0.87) among women with BMI < 18.5 kg/m(2), 1.41 (95% CI: 1.31 - 1.52) among women with BMI 23.0 - 24.9 kg/m(2), and 1.93 (95% CI: 1.73 - 2.16) among women with BMI > or = 25.0 kg/m(2). After controlling for area, maternal age at delivery, educational level, occupation, parity, times of prenatal visit as well as the individual or family history of chronic hypertension, the estimated RR were 0.85 (95% CI: 0.80 - 0.90), 1.37 (95% CI: 1.27 - 1.47) and 1.88 (95% CI: 1.68 - 2.10), respectively.</p><p><b>CONCLUSION</b>High prepregnancy BMI could increase the risk of PIH.</p>
Subject(s)
Adult , Female , Humans , Pregnancy , Body Mass Index , Hypertension, Pregnancy-Induced , Epidemiology , Incidence , Logistic Models , Rural Population , Urban PopulationABSTRACT
Objective To assess the relationship between pre-pregnancy body mass index(BMI),weight gain during pregnancy,and the risk of neonatal asphyxia.Methods Data was collected in 6 counties/cities covered by Peri-natal Health Care Surveillance System which was part of a Sino-American cooperative project on neural tube defects prevention established in 1992.The study population consisted of 83 030 women who attended premarital/preconception medical physical examination program and had delivered single live birth with at least 20 gestational weeks from 1995 to 2000 in Jiaxing area,Zhejiang province.Results from the Chi-square test were employed to test the differences in the rates of neonatal asphyxia between groups with different BMI and other characteristics.Multivariate logistic regression method was conducted to examine the association between pre-pregnancy BMI,gestational weight gain,and the risk of asphyxia.Results The average rate of neonatal asphyxia was 11.3%(95% CI:11.1%-11.6%).The rates of neonatal asphyxia among women with BMI＜18.5 kg/m2,18.5-22.9 kg/m2,23.0-24.9 kg/m2,and≥25.0 kg/m2 were 11.0%(95% CI:10.5%-11.5%),11.3%(95% CI:11.1%-11.6%),11.8%(95% CI:11.0%-12.6%),and 12.9%(95% CI:11.6%-14.4%)respectively.The rates of neonatal asphyxia were 12.4% among women with weight gain＜0.3 kg/wk.higher than women with higher weight gain.After adjusting for residencial area,maternal age,educational level,occupation,parity,times of prenatal visit,high-risk experiences during pregnancy,high-risk experiences at time of delivery,gestational week and birth weight,the estimated ORs were 1.03(95% CI:0.97-1.09),1.06(95% CI:0.96-1.16)and 1.14(95% CI:1.00-1.31),respectively.These ORs became 1.02(95% CI:0.95-1.09),1.01(95% CI:0.90-1.13)and 1.08(95% CI:0.92-1.28)after further adjusting the variable "gestational weight gain".The estimated ORs for neonatal asphyxia were 1.06(95% CI:1.01-1.12)for women with weight gain at 0.3-kg/wk and 1.09(95% CI:1.02-1.20)for women with weight gain＜0.3 kg/wk when compared to those with weight gain≥0.5 kg/wk.Conclusion Lower weight gain seemed to have the effect of increasing the risk of neonatal asphyxia.
ABSTRACT
<p><b>OBJECTIVE</b>To describe the epidemiological characters of pregnancy-induced hypertension (PIH) in Jiaxing areas of Zhejiang province of China between 1995 and 2000.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>