Table 1

Demographic and reproductive characteristics of study population by pregnancy-induced hypertension, Suzhou, China, 1989–1990

Subjects










Characteristics*
 No.
 %
 Normotensive
(N=10,669) %
Gestational hypertension
(N=782) %
 Preeclampsia
(N=365) %
 Severe preeclampsia
(N=105) %
 Statistical significance
(χ2test)
Maternal age






≤30
 11,230
 94.2
 94.6
 90.3
 91.5
 94.3
 0.000
> 30
 691
 5.8
 5.4
 9.7
 8.5
 5.7








Parity






Nulliparous
 11,365
 95.3
 95.3
 94.9
 97.8
 97.1
 0.100
Multiparous
 556
 4.7
 4.7
 5.1
 2.2
 2.9








Sex






Male
 6,026
 50.5
 50.8
 48.6
 47.4
 55.2
 0.290
Female
 5,895
 49.5
 49.2
 51.4
 52.6
 44.8








Preterm birth (<37 weeks)






No
 11,527
 96.7
 96.6
 98.2
 96.7
 93.3
 0.023
Yes
 394
 3.3
 3.4
 1.8
 3.3
 6.7








Low birth weight (<2,500 g)






No
 11,620
 97.5
 97.6
 97.3
 95.1
 92.4
 0.000
Yes
 301
 2.5
 2.4
 2.7
 4.9
 7.6








Mean gestational age (Weeks)
 39.30
39.29
 39.44
 39.30
 38.69
 0.000 (Analysis of variance)
Place of delivery






Hospital
 11,900
 99.8
 99.8
 99.7
 100
 100
 0.981
Home
 11
 0.1
 0.1
 0.1
 0
 0








BMI






< 24
 11,012
 92.8
 93.1
 90.0
 89.6
 93.3
 0.005
24–28
 426
 3.6
 3.4
 5.3
 5.8
 4.8
> 28
 432
 3.6
 3.5
 4.7
 4.6
 1.9








Infant complications No Yes






No
 10,989
 93.1
 93.1
 90.9
 87.0
 88.5
 0.000
Yes
 810
 6.9
 6.4
 9.1
 13.0
 11.5

* Excluding cases with missing information.

Baulon et al. BMC Pregnancy and Childbirth 2005 5:10   doi:10.1186/1471-2393-5-10