Table 1. Baseline Characteristics of Study Participants by Breastfeeding Duration
TotalNulliparousParous Women, by Breastfeeding Duration Per Child
Never>0 to 6 mo6 to 12 mo12 to 18 mo18 to 24 mo>24 mo
No. (% rural)289 573 (44)3970 (37)7785 (29)17 780 (37)131 546 (44)65 685 (68)42 728 (79)20 079 (83)
Age, y50.5 (10.3)49.0 (11.7)47.3 (9.2)47.0 (9.3)50.1 (10.2)50.7 (10.4)52.2 (10.8)53.8 (9.7)
Education level, %
Primary or below56.839.626.234.251.859.174.279.5
Secondary or above43.360.473.865.748.240.925.720.4
Household income, %
Low10.211.14.65.05.611.818.823.2
Middle49.151.840.939.941.454.963.361.5
High40.737.154.455.153.133.317.915.3
Current smoking, %2.33.82.31.81.63.02.73.9
Regular alcohol use, %2.13.22.92.61.72.51.92.4
Physical activity, MET h/d17.2 (11.0–28.7)15.0 (9.3–25.0)16.6 (10.5–26.7)18.0 (11.2–29.1)17.3 (10.8–28.7)17.0 (11.2–28.0)18.4 (11.0–30.3)16.5 (10.7–28.0)
Systolic blood pressure, mm Hg129.4 (21.8)126.3 (23.0)123.3 (19.8)123.1 (19.8)128.2 (21.2)130.2 (21.6)133.3 (22.8)135.2 (23.0)
Diastolic blood pressure, mm Hg76.7 (10.8)75.5 (11.2)75.4 (10.7)74.9 (10.5)76.3 (10.7)77.0 (10.8)77.7 (11.2)78.0 (11.3)
Body mass index, kg/m223.8 (3.4)23.3 (3.7)23.7 (3.4)23.4 (3.3)23.7 (3.4)23.9 (3.5)23.9 (3.5)24.0 (3.6)
History of hypertension, %10.28.88.67.710.710.410.010.4
History of diabetes mellitus, %2.92.53.32.53.02.92.62.7
No. of livebirths, %
1 35.2077.360.642.829.815.014.4
2 31.9014.426.131.733.935.338.1
≥3 31.508.413.325.636.349.747.5
Breastfeeding duration, mo
Lifetime duration24.0 (12.0–48.0)NANA6.0 (3.0–9.0)20.0 (12.0–24.0)34.0 (18.0–48.0)48.0 (42.0–72.0)78.0 (60.0–108.0)
Mean duration per child12.0 (11.0–18.0)NANA5.0 (3.0–6.0)12.0 (10.0–12.0)15.7 (14.0–18.0)24.0 (21.0–24.0)30.0 (27.4–36.0)
Age at menarche, y15.4 (2.0)15.2 (2.6)14.8 (1.9)14.9 (1.9)15.3 (1.9)15.5 (1.9)15.7 (2.0)16.0 (2.0)
Age at first birth, y23.4 (3.2)NA25.8 (3.8)24.7 (3.4)23.6 (3.2)23.0 (3.0)22.5 (2.9)22.6 (2.8)
History of miscarriage, %8.479.26.96.57.39.811.612.8
History of induced abortion, %51.490.864.066.159.349.634.835.1
History of stillbirth, %5.175.64.83.95.66.05.55.3
  • MET indicates metabolic equivalent; NA, not available.

  • Values are percentages for categorical variables, and means and SD or median and 25th and 75th percentile for continuous variables.