Project Viva: a Longitudinal Study of Health for the Next Generation

Cross-sectional and longitudinal measurements of child BMI z-score in kg/m^2, standardized into a sex- and age-specific z-score using national reference data (CDC growth charts)

时间窗: Research measurements at birth, 6mo, early childhood (~3y), mid-childhood (~8y), early teen (~14y), and mid-late teen (~17y).

The study team measures child weight and length/height at each time point, and BMI is calculated and standardized based on the child's age at the time of measurement.

Child neurodevelopment, assessed by continuous scores on the Wide Range Assessment of Memory and Learning, Second Edition (WRAML2), Design and Picture Memory subtests and The Kaufman Brief Intelligence Test, Second Edition (KBIT-2)

时间窗: Children completed both the WRAML2 and the KBIT-2 at the mid-childhood visit (~8y)

Maternal post-partum weight retention, calculated as the difference between weight in kg at 1 year postpartum and pre-pregnancy weight

时间窗: Before the Project Viva pregnancy and 1-year postpartum

Investigators obtained prenatal weights from the clinical record, and calculated total gestational weight gain (GWG) as the difference between the last weight recorded in the 4 weeks prior to delivery and pre-pregnancy weight. Project Viva mothers reported their weight at 1-year postpartum via questionnaire.

Child metabolic risk score, calculated as a standard deviation (SD) score

时间窗: HDL-cholesterol, triglycerides, insulin, glucose and waist circumference measured at ~8y, ~14y, and ~17y of age. Blood pressure measured at birth, ~6mo, ~3y, ~8y, ~14y, and ~17y. Metabolic risk score calculated at ~8y, ~14y, and ~17y.

Investigators derived the metabolic risk score as the mean of 5 sex- and cohort-specific z-scores for: waist circumference (cm), systolic blood pressure (SBP, calculated as the average of 5 measurements taken 1 minute apart), HDL cholesterol (mg/dL, scaled inversely), log-transformed triglycerides (mg/dL) and log-transformed HOMA-IR (calculated as fasting insulin \[μU/mL\] x fasting glucose \[mg/dL\]/405).

Mother's report of a clinical diagnosis of asthma, wheeze or reactive airway disease

时间窗: Interviews administered at 6mo, early childhood (~3y), mid-childhood (~8y), early teen (~14y), and mid-late teen (~17y).

Mothers answered yes or no when asked "have you ever been told by a health care professional, such as a doctor, physician assistant or nurse practitioner, that your child has… 1. Asthma? 2. Wheezing or reactive airways? Mothers reported asthma, wheezing and reactive airways as a single outcome at the infancy visit and separately at the early and mid-childhood visits. At the early teen visit, the mother reported a diagnosis of asthma only.