Table 3.
Associations between gestational age z-score and selected adverse perinatal outcomes among women with grade 1 obesity (n=148,335), grade 2 obesity (n=72,032), or grade 3 obesity (n=47,494), Pennsylvania singleton birth certificates, 2003–2011.
| Gestational weight gain z-score |
Total gestational weight gain equivalent at 40 weeks, kg |
Cesarean delivery | Adjusted a differences in risk per 100 births (95% CI) | Neonatal intensive care unit admission |
||
|---|---|---|---|---|---|---|
| Large-for- gestational-age birth |
Small-for- gestational-age birth |
Preterm birth | ||||
| Grade 1 obesityb | ||||||
| −3 SD | −4.3 | −1.6 (−2.5, −0.64) | −0.32 (−0.73, −0.09) | 1.4 (0.97, 1.8) | 0.89 (0.47, 1.32) | 0.52 (0.21, 0.83) |
| −2 SD | 0.05 | −0.92 (−1.3, −0.51) | −0.30 (−0.48, −0.12) | 0.81 (0.63, 0.99) | 0.43 (0.26, 0.61) | 0.23 (0.09, 0.36) |
| −1.1 SD | 5.0c | Ref | Ref | Ref | Ref | Ref |
| −1 SD | 5.6 | 0.19 (0.16, 0.22) | 0.11 (0.96, 0.12) | −0.16 (−0.18, −0.14) | −0.57(−0.07, −0.04) | −0.02 (−0.03, −0.01) |
| −0.5 SD | 9.0 | 1.6 (1.5, 1.8) | 1.2 (1.1, 1.2) | −1.3 (−1.5, −1.2) | −0.38 (−0.49, −0.27) | −0.08 (−0.16, −0.003 |
| 0 | 12.9 | 4.2 (3.7, 4.7) | 3.5 (3.2, 3.7) | −2.8 (−3.2, −2.6) | −0.74 (−1.0, −0.48) | −0.68 (−0.29, 0.13) |
| 0.5 SD | 17.3 | 7.4 (6.7, 8.2) | 6.6 (6.1, 7.0) | −4.1 (−4.4, −3.7) | −0.67 (−1.1, −3.0) | 0.13 (−0.15, 0.43) |
| 1 SD | 22.3 | 11 (10, 12) | 9.4 (8.9, 9.9) | −4.5 (−4.9, −4.1) | 0.14 (−0.24, 0.53) | 0.62 (0.29, 0.93) |
| 2 SD | 34.6 | 18 (17, 20) | 15 (14, 16) | −4.8 (−5.2, −4.3) | 3.3 (2.6, 3.9) | 2.1 (1.5, 2.6) |
| Grade 2 obesity | ||||||
| −3 SD | −8.2 | −1.7 (−2.7, −0.68) | −0.71 (−1.2, −0.24) | 1.8 (1.4, 2.1) | 1.1 (0.70, 1.5) | 0.49 (0.19, 0.78) |
| −2 SD | −4.0 | −1.5 (−2.1, −0.96) | −0.81 (−1.1, −0.55) | 1.3 (1.1, 1.6) | 0.69 (0.47, 0.90) | 0.27 (0.10, 0.43) |
| −1 SD | 1.8 | −1.01 (−1.2, −0.84) | −0.65 (0.84, 1.03) | 0.69 (0.58, 0.80) | 0.24 (0.16, 0.34) | 0.06 (−0.01, 0.12) |
| −0.6 SD | 5.0c | Ref | Ref | Ref | Ref | Ref |
| −0.5 SD | 5.6 | 0.39 (0.33, 0.47) | 0.28 (0.25, 0.31) | −0.23 (−0.28, −0.19) | −0.07 (−0.11, −0.04) | −0.01 (−0.04, 0.01) |
| 0 | 9.9 | 3.5 (2.9, 4.1) | 2.7 (2.5, 3.1) | −1.8 (−2.1, −1.5) | −0.48 (−0.74, −0.22) | −0.022 (−0.24, 0.19) |
| 0.5 SD | 15.1 | 7.7 (6.6, 8.8) | 6.6 (5.9, 7.2) | −2.9 (−3.3, −2.5) | −0.34 (−0.78, 0.10) | 0.25 (−0.096, 0.68) |
| 1 SD | 21.1 | 12 (10, 12) | 10 (9, 11) | −3.3 (−3.7, −2.8) | 1.01 (0.51, 1.51) | 1.2 (0.77, 1.7) |
| 2 SD | 36.6 | 19 (16, 22) | 18 (17, 21) | −3.2 (−3.9, −2.4) | 6.6 (5.2, 7.9) | 4.5 (3.4, 5.5) |
| Grade 3 obesity | ||||||
| −3 SD | −12.0 | −3.4 (−4.5, −2.3) | −2.8 (−3.3, −2.3) | 2.5 (1.9, 3.1) | 1.2 (0.71, 1.7) | 0.44 (0.08, 0.79) |
| −2 SD | −8.2 | −3.2 (−4.1, −2.3) | −2.8 (−3.2, −2.4) | 2.4 (1.9, 2.9) | 0.99 (0.55, 1.4) | 0.32 (−0.001, 0.63) |
| −1 SD | −2.3 | −2.7 (−3.5, −1.9) | −2.6 (−2.9, −2.3) | 2.1 (1.6, 2.6) | 0.76 (0.37, 1.2) | 0.20 (−0.079, 0.48) |
| −0.5 SD | 1.8 | −1.1 (−1.5, −0.74) | −1.3 (−1.5, −1.2) | 1.1 (0.89, 1.3) | 0.49 (0.29, 0.68) | 0.19 (0.049, 0.34) |
| −0.2 SD | 5.0c | Ref | Ref | Ref | Ref | Ref |
| 0 | 6.8 | 0.68 (0.53, 0.81) | 0.16 (0.01, 0.24) | 0.15 (0.098, 0.20) | 0.26 (0.21, 0.31) | 0.22 (0.17, 0.25) |
| 0.5 SD | 13.1 | 5.7 (4.7, 6.7) | 5.3 (4.7, 5.9) | −1.5 (−1.8, −1.2) | 0.39 (0.009, 0.78) | 0.66 (0.34, 0.99) |
| 1 SD | 20.8 | 9.6 (8.2, 11) | 9.8 (8.9, 11) | −1.8 (−2.2, −1.4) | 2.1 (1.6, 2.6) | 1.9 (1.4, 2.3) |
| 2 SD | 42.4 | 18 (13, 22) | 22 (18, 25) | −1.7 (−2.9, −0.45) | 8.6 (6.3, 11) | 5.7 (3.9, 7.6) |
Adjusted for maternal age, maternal race/ethnicity, maternal education, marital status, parity, smoking during pregnancy, pre-existing diabetes or hypertension, height, Black racial composition of neighborhood, payment source, urban residence, neonatal care level of the birth facility, and year of birth.
Grade 1 obesity, body mass index 30–34.9 kg/m2; grade 2 obesity, body mass index 35−39.9 kg/m2; grade 3 obesity, body mass index ≥40 kg/m2
The reference group for each body mass index group was the z-score equivalent to 5 kg, the lower limit of the 2009 Institute of Medicine recommended weight gain range for obese women.8