Table 2.
Crude and Multivariable-Adjusted Risk Ratios (RR) and 95% Confidence Intervals (CI) for Offspring Obesity Associated With Cesarean vs. Vaginal Delivery. Data from the Growing Up Today Study, 1996–2011.
| Variable | Obese/participants (%) | RR (95%CI) ) for Offspring Obesity | |
|---|---|---|---|
| Main analyses | 2,766/22,068 (13%) | ||
| Vaginal Delivery | 2,012/17,147 (12%) | 1.00 (ref) | |
| Cesarean Delivery (Crude) | 754/4,921 (15%) | 1.30 (1.21, 1.41) | <0.001 |
| Cesarean Delivery (Model 1)1 | 754/4,921 (15%) | 1.15 (1.06, 1.26) | 0.002 |
| Sensitivity analyses | |||
| Propensity-score based estimate2 | 754/4,921 (15%) | 1.17 (1.08, 1.27) | <0.001 |
| Treating maternal BMI as continuous variable3 | 754/4,921 (15%) | 1.13 (1.03, 1.23) | <0.001 |
| Repeated measures estimate4 | 754/4,921 (15%) | 1.23 (1.11, 1.37) | <0.001 |
| Restricted to no known risk factors for cesarean5 (N=8566) | 200/1,503 (13%) | 1.30 (1.09, 1.54) | 0.004 |
| Restricted to siblings (N=12903) | 417/2748 (15%) | 1.24 (1.10, 1.41) | <0.001 |
Model 1 was adjusted for maternal age at delivery, race (white, other), maternal pre-pregnancy BMI group (<18.5, 18.5–24.99, 25–29.99, 30+ kg/m2), maternal height, gestational diabetes (yes, no), preeclampsia (yes, no), pregnancy induced hypertension(yes, no), child sex (male, female), year of birth (<=1984, 1985–1989, >1989), gestational age at delivery (<37, 37–39, 40–42, 43+ weeks), previous Cesarean section(yes, no), birth order, birth weight group (<5, 5–6.9, 7–8.4,8.5–9.9, 10+ lbs), pre-pregnancy smoking (never, past, current) and region of residence at birth (Northeast, Midwest, West, South).
Propensity-score based estimate using marginal structural model where the probability of undergoing a cesarean section was predicted for each woman based on these same factors and subsequently used to weight each observation using stabilized weights.
This model adjusted for the same covariates in model 1 but modeling pre-pregnancy BMI as a continuous variable with a linear term and a quadratic term instead of categorical.
GEE estimate using repeated obesity status during each follow up cycle.
Subgroup of participants without known risk factors for cesarean (maternal pre-pregnancy BMI<25kg/m2, no gestational diabetes, no hypertensive disorders of pregnancy, never smoker, maternal age<30 years old, gestational age at delivery between 37 and 42 weeks, and birth weight between 5 and 9.9 lbs).