Cobas c 111 instrument

In addition to self-reported information of race/ethnicity and smoking status during pregnancy on birth certificates, ICD-9 codes (online supplementary appendix 1) from hospital discharge records were used to identify patients with diabetes (types 1 and 2 as well as gestational) and hypertension, which was further subdivided into the categories of chronic hypertension, gestational hypertension and pre-eclampsia de novo or imposed on prior hypertension. Obesity was measured as body mass index (BMI) in kg/m² at onset of pregnancy with cutpoints of <18.5 for underweight, 18.5–24.9 for normal, 25–29.9 for overweight and ≥30 for obese. Serum samples from the California Biobank were collected at 15 to 20 weeks gestation during pregnancy, separated and stored at −80 degrees, then aliquoted and tested with enzymatic colorimetric tests on a Roche Cobas c111 instrument to measure total cholesterol (mg/dL), LDL (mg/dL), high-density lipoprotein (HDL) (mg/dL) and triglycerides (mg/dL).