Postpartum cardiovascular risk screening
At 6 months postpartum, all women underwent physical and biochemical CVR screening in the Maternal Health Clinic (Kingston General Hospital) or at The Ottawa Hospital (Ottawa) according to published protocol.28 A full medical history was taken and included information on family history, breastfeeding and lifestyle such as smoking status and alcohol intake. A physical examination, specifically focusing on cardiovascular-related clinical predictors, was performed and collected information on weight, height, and blood pressure. A maternal blood sample was collected and total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, glucose and C-reactive protein were quantified for each participant. A random urine sample was collected and the albumin:creatinine ratio was measured. Physical and biochemical CVR findings were integrated to calculate a lifetime risk score for CVD, according to the previously published protocol.28 Calculations for lifetime cardiovascular risk are based on the following risk factors: total cholesterol, systolic blood pressure, diastolic blood pressure, use of antihypertensive medication(s), fasting blood glucose, diagnosis of diabetes and current smoking status. Risk stratification for each risk factor was based on predetermined measurement thresholds (optimal, not optimal, elevated, major). Lifetime cardiovascular risk estimates are also categorical and based on the total number of optimal, not optimal, elevated and major risk factors of each individual (8%, all risk factors are optimal; 27%, ≥1 risk factor is not optimal; 39%, ≥1 risk factor is elevated; 39%, 1 risk factor is major; 50%, ≥2 risk factors are major). Lifetime cardiovascular risk estimates were simplified to categorize woman as low risk (<39% risk) or high risk (≥39% risk) for lifetime CVD. This threshold corresponds to the baseline lifetime CVD risk attributed to healthy women enrolled in the Framingham Heart Study.34