Pre-pregnancy BMI, gestational weight gain and risk of preeclampsia: a birth cohort study in Lanzhou, China

Table 1 Distribution of Selected Characteristics of the Study Population

Characteristics	All participants		Preeclampsia		P-value^a
Characteristics	n	(%)	n	(%)	P-value^a
All	9863	100	347	3.5
Maternal age					<0.001
< 25y	4780	48.5	131	2.7
25-29y	1530	15.5	52	3.4
≥ 30y	3553	36.0	164	4.6
Employment status					0.0012
Yes	5180	52.5	151	2.9
Not during pregnancy	1524	15.5	56	3.7
Never	3159	32.0	140	4.4
Monthly income (RMB)					<0.0001
< 3000	4995	50.6	227	4.5
≥ 3000	3998	40.5	84	2.1
Education level					<0.0001
≥ college	3734	37.9	83	2.2
< college	5878	59.6	250	4.3
Parity					0.0035
Multifarious	2679	27.2	118	4.4
Primiparous	7184	72.8	229	3.2
Newborn gender					0.0073
Male	5200	52.7	159	3.1
Female	4633	47.0	188	4.1
Twin					<0.0001
Yes	284	2.9	58	20.4
No	9579	97.1	289	3.0
Family history of hypertension					<0.0001
Yes	1510	15.3	91	6.0
No	8353	84.7	256	3.1
Pre-pregnancy BMI^b
Normal weight	6699	67.9	221	3.3	<0.0001
Underweight	2104	21.3	46	2.2
Overweight	1060	10.7	80	7.5
Gestational weight gain(GWG)					<0.0001
Inadequate	1323	13.4	33	2.5
Adequate	3279	33.2	62	1.9
Excessive	5261	53.3	252	4.8
Maternal diabetes
Yes	97	1.0	7	7.2	0.085^*
No	9766	99.0	340	3.5
Smoking (passive and active) during pregnancy					0.323
Yes	1928	19.5	75	3.9
No	7935	80.5	272	3.4
Alcohol consumption during pregnancy					1^*
Yes	17	0.2	0
No	9846	99.8	347	3.5
Physical activity during pregnancy					0.796
Yes	8250	83.6	292	3.5
No	1613	16.4	55	3.4

^aThe analysis did not account for missing data. For variable Monthly income (RMB), data was missing for 870 participants, for variable Education level, data was missing for 251 participants, for variable Newborn gender, data was missing for 30 participants
^bWeight(kg) / height² (m²)
^*Fisher’s exact test, for all other variables Chi-square test

ISSN: 1471-2393