Hypertensive disorders of pregnancy (HDP) are a leading cause of maternal and perinatal morbimortality. Dietetic, phenotypic, and genotypic factors influencing HDP were analyzed during a nutrigenetic trial in Rio de Janeiro, Brazil (2016–2020). Pregnant women with pregestational diabetes mellitus (n = 70) were randomly assigned to a traditional or DASH diet group. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured during prenatal visits and HDP were diagnosed using international criteria. Phenotypic data were obtained from medical records and personal interviews. Genotyping for FTO and ADRB2 polymorphisms used RT-PCR. Linear mixed-effect models and time-to-event analyses were performed. The variables with significant effect on the risk for progression to HDP were: black skin color (adjusted hazard ratio [aHR] 8.63,p= 0.01), preeclampsia in previous pregnancy (aHR 11.66,p< 0.01), SBP ≥ 114 mmHg in the third trimester (aHR 5.56,p0.04), DBP ≥ 70 mmHg in the first trimester (aHR 70.15,p= 0.03), mean blood pressure > 100 mmHg (aHR 18.42,p= 0.03), and HbA1c ≥ 6.41% in the third trimester (aHR 4.76,p= 0.03). Dietetic and genotypic features had no significant effect on the outcome, although there was limited statistical power to test both.