Table 1.
Characteristics of Mothers and Their Infants Grouped by Body Mass Index Category and Gestational Weight Gain
| |
|
Group |
|
||||
|---|---|---|---|---|---|---|---|
| Variable | Total sample (n=718) | NR (n=162) | OOR (n=58) | NM (n=237) | OWM (n=156) | OBM (n=105) | p value |
| Prepregnancy BMI (kg/m2) | 25.9±5.8 | 21.9±1.8 | 32.5±6.7 | 22.1±1.8 | 17.0±1.4 | 35.3±4.2 | <0.01 |
| GWG (kg) | 16.6±6.1 | 13.4±1.3 | 8.0±1.7 | 20.4±4.1 | 17.7±7.2 | 15.9±6.4 | <0.01 |
| Age (years) | 28.7±5.5 | 29.5±5.6 | 29.7±5.5 | 28.3±5.4 | 28.5±5.6 | 28.4±5.6 | 0.14 |
| Parity | 0.10 | ||||||
| 0 | 51.4 | 50.6 | 36.2 | 56.1 | 52.6 | 51.4 | |
| 1 | 32.4 | 32.1 | 41.4 | 32.1 | 26.9 | 26.9 | |
| ≥2 | 16.8 | 17.3 | 22.3 | 11.8 | 20.6 | 19.2 | |
| Vaginal delivery (%) | 67.1 | 77.2 | 60.3 | 68.8 | 65.4 | 54.3 | <0.01 |
| Married (%) | 78.5 | 84.0 | 81.0 | 78.0 | 76.8 | 72.1 | 0.27 |
| Education (%) | <0.01 | ||||||
| <High school | 2.5 | 2.5 | 0 | 1.3 | 3.2 | 5.7 | |
| High school | 15.6 | 8.6 | 15.5 | 20.0 | 14.1 | 19.0 | |
| Some college or more | 81.8 | 88.9 | 84.5 | 78.7 | 82.8 | 75.3 | |
| Race (%) | 0.08 | ||||||
| White | 90.6 | 88.1 | 89.7 | 92.4 | 91.7 | 89.5 | |
| Asian | 3.4 | 7.5 | 1.7 | 1.7 | 3.2 | 1.9 | |
| Black | 5.0 | 3.8 | 3.8 | 3.8 | 4.5 | 8.6 | |
| Other | 1.0 | 0.6 | 0 | 2.1 | 0 | 0 | |
| Hispanic/Latino ethnicity (%) | 5.9 | 6.2 | 8.6 | 5.9 | 5.8 | 3.8 | 0.80 |
| WIC enrolled (%) | 17.0 | 14.2 | 15.5 | 16.0 | 16.0 | 25.7 | 0.14 |
| Smoked during pregnancy (%) | 8.8 | 4.3 | 3.4 | 11.0 | 10.3 | 11.4 | 0.06 |
| Plans to work after delivery (%) | 78.7 | 73.1 | 80.7 | 78.8 | 78.6 | 86.4 | 0.15 |
| Planned breastfeeding duration (months) | 7.9±4.4 | 8.2±4.6 | 8.3±4.1 | 8.0±4.3 | 7.2±4.2 | 8.3±5.0 | 0.28 |
| Maternal rating of breastfeeding importance (%) | 0.14 | ||||||
| Not very important | 0.3 | 0 | 0 | 0.8 | 0 | 0 | |
| Somewhat important | 7.9 | 7.4 | 3.4 | 5.1 | 11.5 | 12.4 | |
| Very important | 43.9 | 43.8 | 55.2 | 43.9 | 39.1 | 44.8 | |
| Extremely important | 47.9 | 48.8 | 41.4 | 50.2 | 49.4 | 42.9 | |
| Infant birth weight (kg) | 3.46±0.48 | 3.33±0.52 | 3.41±0.45 | 3.52±0.48 | 3.53±0.42 | 3.47±0.51 | <0.01 |
| Gestational age (weeks) | 39.3±1.2 | 39.2±1.2 | 38.9±1.4 | 39.5±1.2 | 39.3±1.2 | 39.2±1.3 | <0.01 |
| Using formula prior to hospital discharge (%) | 30.9 | 23.5 | 29.3 | 27.0 | 37.8 | 41.9 | <0.001 |
| Milk came in later than 4 days postdelivery (%) | 16.9 | 13.0 | 10.3 | 16.5 | 17.4 | 26.7 | 0.03 |
| Maternal report of (%) | |||||||
| Milk “took too long to come in” | 21.7 | 21.0 | 17.5 | 21.6 | 22.7 | 23.8 | 0.91 |
| “Pain while breastfeeding in the first 2 weeks” | 63.6 | 73.5 | 60.3 | 65.0 | 59.4 | 53.3 | 0.01 |
| “Baby had trouble sucking or latching on” | 52.5 | 50.6 | 54.4 | 54.7 | 50.0 | 53.3 | 0.88 |
| “Nipples were sore, cracked, or bleeding” | 60.4 | 69.8 | 50.9 | 65.3 | 53.9 | 49.5 | 0.001 |
Groups were named by prepregnancy body mass index (BMI) category (normal, overweight, or obese)/adherence to Institute of Medicine gestational weight gain (GWG) guidelines (recommended weight gain, more), leading to the following group names: Normal/Recommended (NR), Overweight-Obese/Recommended (OOR), Normal/More (NM), Overweight/More (OWM), and Obese/More (OBM).
In univariable Cox proportional hazards models all covariates considered except race and gestational age were significantly associated with breastfeeding duration.
WIC, Women, Infants and Children supplemental nutrition program.