Objective: To determine the predictors of hypercholesterolemia and of hypertriglyceridemia during the first half of pregnancy in Mexican women. Methods: Cross-sectional comparative study of pregnant women with less than 21 weeks of gestational age. Measurements: Demographic information, obstetric history, prepregnancy body mass index, cholesterol and triglycerides. Cross tabulations and multiple logistic regression were used for statistical analysis. Results: 230 participants; 61 women with normal prepregnancy body mass index, 108 with overweight, and 61 with obesity. Dyslipidemia was defined as elevated cholesterol (>180 mg/dL) or triglycerides (>170 mg/dL). After adjusting by potential confounders, independent predictors of hypercholesterolemia included being overweight (OR=2.8, 95% CI 1.4-5.9), being obese (OR=3.7 95% CI 1.6-8.4) or being on the second trimester of pregnancy. The same predictors were found for hypertriglyceridemia, respectively OR=2.8, 95% CI 1.4-5.6, OR=2.9, 95% CI 1.3-6.5, OR=2.6, 95% CI 1.4-4.7. Conclusion: Mexican women with prepregnancy overweight or obesity have greater risk of suffering hypercholesterolemia and hypertriglyceridemia during pregnancy. Women in the second trimester had higher levels of both lipids as compared to the first one. This is the first Mexican study that confirms the increase of lipids as gestational age progresses.