[Relationship between maternal age and hypertensive disorders in pregnancy]

To explore the current status of maternal age and hypertensive disorders in pregnancy related to maternal age in China.

The clinical data were collected from 39 hospitals in mainland China. All deliveries were performed after 28 weeks of completed gestation between January 1 and December 31, 2011. A total of 110 450 cases were enrolled and divided into 6 groups at 5-year intervals according to maternal age. The 25-29 age group was selected as a reference group. The odds ratio (OR) and 95% confidence interval (CI) were calculated by unadjusted binary-Logistic regression as appropriate.

The mean age of pregnant women at the time of delivery was 28.18 ± 4.70 (14-52) years. The risk of hypertensive disorders in pregnancy increased in the 3 age groups above 30 years (OR: 30-34 age group = 1.3, 35-39 age group = 2.3, ≥ 40 age group = 3.3) . The risks of chronic hypertension and pregnancy-induced hypertension increased gradually with maternal age. The risks of preeclampsia and severe preeclampsia showed a U-type distribution. The risk was the lowest in the 25-29 age group and the highest in the ≥ 40 age group (OR = 3.6 and 3.4). The rate of eclampsia was 0 in the ≥ 40 age group and the highest in the teenage group (OR = 8.7). And it was higher in the 20-24 age group (OR = 2.6). No significant difference existed between other age groups and the 25-29 age group.

The risk of hypertensive disorders in pregnancy increases gradually with age in pregnant women aged over 35 years. And the risks of preeclampsia and eclampsia rise in teenage pregnancy. Better management helps to reduce the incidence of eclampsia and improve the outcomes of pregnancy in pregnant women with advanced maternal age and teenages.