Table 2.
Gestational weight gain outside versus within the Institute of Medicine recommendations (2009) and the adverse pregnancy outcomes
| BMI category | No. studies (women) | OR (95% CI) | No. studies (women) | aOR (95% CI) | No. studies (women) | OR (95% CI) | No. studies (women) | aOR (95% CI) |
|---|---|---|---|---|---|---|---|---|
| Gestational weight gain above the IOM recommendations | ||||||||
| Caesarean sectiona | Preterm birthb | |||||||
| All womene | 30 (2727) | 1.42 (1.20, 1.68) | 24 (2700) | 1.50 (1.25, 1.80) | 30 (3126) | 0.75 (0.50, 1.11) | 26 (2769) | 0.84 (0.54, 1.29) |
| Healthy BMIf (16 kg) | 21 (949) | 1.36 (0.96, 1.92) | 21 (781) | 1.58 (1.09, 2.28) | 21 (971) | 1.40 (0.70, 2.80) | 19 (809) | 1.73 (0.82, 3.65) |
| Overweight (11.5 kg) | 29 (982) | 1.43 (1.04, 1.98) | 23 (877) | 1.68 (1.19, 2.35) | 29 (1000) | 0.32 (0.15, 0.68) | 25 (897) | 0.40 (0.18, 0.86) |
| Obese (9 kg) | 30 (1143) | 1.29 (1.00, 1.68) | 24 (1042) | 1.44 (1.10, 1.89) | 30 (1155) | 0.81 (0.41, 1.59) | 26 (1063) | 0.89 (0.44, 1.80) |
| Large for Gestational Agec | Small for Gestational Aged | |||||||
| All womene | 31 (3138) | 1.85 (1.47, 2.32) | 30 (3123) | 2.00 (1.58, 2.54) | 30 (3123) | 0.68 (0.52, 0.87) | 25 (2754) | 0.66 (0.50, 0.87) |
| Healthy BMI (16 kg) | 21 (973) | 1.77 (1.17, 2.70) | 20 (967) | 1.68 (1.10, 2.56) | 21 (970) | 0.89 (0.54, 1.44) | 18 (803) | 0.93 (0.56, 1.56) |
| Overweight (11.5 kg) | 29 (1003) | 1.68 (1.11, 2.53) | 28 (998) | 1.83 (1.20, 2.80) | 29 (1000) | 0.44 (0.27, 0.74) | 24 (897) | 0.51 (0.30, 0.87) |
| Obese (9 kg) | 31 (1162) | 2.53 (1.67, 3.83) | 30 (1158) | 2.75 (1.80, 4.19) | 30 (1153) | 0.71 (0.48, 1.05) | 25 (1054) | 0.65 (0.42, 0.98) |
| Gestational weight gain below the IOM recommendations | ||||||||
| Caesarean sectiona | Preterm birthb | |||||||
| All womene | 30 (3074) | 0.93 (0.76, 1.13) | 24 (2395) | 0.93 (0.75, 1.13) | 30 (2769) | 1.81 (1.26, 2.59) | 26 (2486) | 1.94 (1.31, 2.88) |
| Healthy BMI (11.5 kg) | 21 (1285) | 0.84 (0.60, 1.17) | 21 (1082) | 0.79 (0.55, 1.14) | 21 (1309) | 1.69 (0.95, 3.01) | 19 (1131) | 1.65 (0.86, 3.17) |
| Overweight (7 kg) | 29 (590) | 0.99 (0.65, 1.51) | 23 (536) | 0.83 (0.53, 1.31) | 29 (601) | 1.28 (0.62, 2.64) | 25 (562) | 1.58 (0.73, 3.43) |
| Obese (5 kg) | 30 (852) | 1.07 (0.80, 1.43) | 24 (777) | 1.10 (0.81, 1.51) | 30 (859) | 2.40 (1.28, 4.50) | 26 (793) | 2.39 (1.22, 4.68) |
| Large for Gestational Agec | Small for Gestational Aged | |||||||
| All womene | 31 (2783) | 0.79 (0.59, 1.05) | 30 (5880) | 0.76 (0.57, 1.02) | 30 (2762) | 1.57 (1.24, 2.00) | 25 (2446) | 1.52 (1.18, 1.96) |
| Healthy BMI (11.5 kg) | 21 (1312) | 0.77 (0.50, 1.18) | 20 (1294) | 0.78 (0.51, 1.20) | 21 (1304) | 1.71 (1.16, 2.51) | 18 (1113) | 1.62 (1.07, 2.45) |
| Overweight (7 kg) | 29 (604) | 0.54 (0.28, 1.02) | 28 (599) | 0.53 (0.27, 1.02) | 29 (601) | 1.24 (0.74, 2.09) | 24 (549) | 1.24 (0.71, 2.16) |
| Obese (5 kg) | 31 (467) | 1.03 (0.62, 1.74) | 30 (864) | 0.98 (0.58, 1.66) | 30 (857) | 1.82 (1.24, 2.66) | 25 (784) | 1.81 (1.22, 2.71) |
BMI Body Mass Index (kg/m2), OR Odds ratio, aOR Adjusted odds ratio, CI Confidence intervals, IOM Institute of Medicine
Models adjustments aAny event of diabetes, age, gestational age at delivery, parity, smoking; bSmoking; cAny event of diabetes, and woman’s age; dSmoking, woman’s age, and parity; and BMI category; eAll relevant confounders and BMI category; statistically significant associations are in bold
Kilogram values in brackets indicate upper (weight gain above) or lower (weight gain below) value of the IOM recommendations (2009) for a given BMI category [20]
fequivalent of BMI termed as normal in the World Health Organization classification [20]