Table 4.

Multiple logistic regression model to validate the independent association of adequate gestational weight gain (GWG) and other confounding factors for term preeclampsia)

	Multiple logistic regression for term preeclampsia (≥37 weeks)
	Coefficient	OR	95% CI	P value
Optimal GWG (Yes/no)	−0.30	0.73	0.59 to 0.92	0.007
Smoking	−0.29	0.74	0.56 to 0.98	0.04
Maternal BMI (increment of 5 kg/m²)	0.06	1.06	1.05 to 1.07	<0.0001
Gestational diabetes mellitus	−0.058	0.94	0.74 to 1.18	0.61
Chronic hypertension	1.51	4.5	3.3 to 6.2	<0.0001
Maternal age (increment of 5 years of age)	0.03	1.03	1.02 to 1.05	<0.0001
Primiparity	1.07	2.9	2.45 to 3.48	<0.0001

Optimal GWG and smoking (negative coefficient) have a similar protective effect of 0.74. Primiparity, maternal body mass index (BMI), chronic hypertension and maternal ages increase the risk. Controlling for all the other factors, maternal prepregnancy BMI is still an independent factor (coefficient 0.06, increment of 6% per increment of 5 kg/m²).