Table 1 Maternal and child characteristics by country of residence (N = 412)
Maternal characteristics | Total (n = 412) | Norway (n = 254) | Sweden (n = 158) | p a |
|---|---|---|---|---|
Maternal age (mean years (sd)) | 29.0(4.3) | 28.8(4.3) | 29.2(4.4) | 0.364 |
missing n(%) | 3(0.7) | 1(0.4) | 2(1.3) | |
Maternal pre-pregnancy BMI (kg/m2) n(%) | 0.031 | |||
Underweight (BMI < 18.5) | 42(10) | 31(12) | 11(7) | |
Normal weight (BMI 18.5–25.0) | 330(81) | 205(81) | 125(80) | |
Overweight (BMI > 25.0) | 38(9.3) | 17(7) | 21(13) | |
missing n(%) | 2(0.4) | 1(0.4) | 1(0.6) | |
Maternal education (years) n(%) | 0.011 | |||
less than 9 | 67(17) | 36(14) | 31(20) | |
9–11 | 205(50) | 142(56) | 63(41) | |
12 or more | 135(33) | 75(30) | 60(39) | |
missing n(%) | 5(1.2) | 1(0.4) | 4(2.5) | |
Maternal smoking at conception (number of cigarettes) n(%) | < 0.001 | |||
0 | 225(55) | 120(47) | 105(67) | |
1–9 | 42(10) | 35(14) | 7(4) | |
10 or more | 145(35) | 99(39) | 46(29) | |
Parity n(%) | 0.245 | |||
1 | 285(69) | 181(71) | 104(66) | |
2 | 127(31) | 73(29) | 54(34) | |
Inter-pregnancy interval (years) n(%) | 0.187 | |||
less than 1.5 | 102(25) | 56(22) | 46(29) | |
1.5–5 | 225(55) | 147(58) | 78(49) | |
5 or more | 85(21) | 51(20) | 34(22) | |
Previous breastfeeding duration (mean months (sd)) | 7.3(5.1) | 7.5(5.2) | 7.1(5.0) | 0.546 |
missing n(%) | 30(7.2) | 13(5.1) | 17(10.8) | |
Maternal weight gain up to 17 weeks of gestation (mean kilograms (sd)) | 3.2(2.6) | 3.1(2.6) | 3.3(2.6) | 0.601 |
missing n(%) | 30(7.2) | 28(11.0) | 2(1.3) | |
Child characteristics at birth | ||||
Sex n (%) | 0.987 | |||
Boys | 211(51) | 130(51) | 81(51) | |
Girls | 201(49) | 124(49) | 77(49) | |
Birth weight (mean grams (sd)) | 3445(592) | 3401 (568) | 3515 (625) | 0.056 |
SGA status n(%) | 0.908 | |||
non-SGA | 275(67) | 169(67) | 106(67) | |
SGA | 137(33) | 85(33) | 52(33) | |
Breastfeeding duration of the index child (mean months (sd)) | 6.5(3.6) | 6.7(3.7) | 6.0(3.2) | 0.030 |
missing n(%) | 16(3.9) | 8(3.1) | 8(5.0) | |
Child characteristics at 5 year follow-up | ||||
Exact age at five-year follow-up (mean years (sd) | 5.2(0.2) | 5.1(0.2) | 5.4(0.1) | < 0.001 |
missing n(%) | 1(0.2) | 0(0) | 1(0.6) | |
Weight | 0.708 | |||
Underweight (< 5th percentile) | 12(3) | 7(3) | 5(3) | |
Normal weight (5th–85th percentile.) | 346(84) | 211(83) | 135(87) | |
Overweight (> 85th percentile) | 30(7) | 21(8) | 9(6) | |
Obese (> 95th percentile) | 22(5) | 15(6) | 7(4) | |
missing n(%) | 2(0.4) | 0(0) | 2(1.3) | |
Subscapular skinfolds (mean mm (sd)) | 5.6(1.7) | 6.0 (1.9) | 5.1 (1.2) | < 0.001 |
Triceps skinfolds (mean mm (sd)) | 10.0(2.2) | 10.4 (2.2) | 9.2 (1.9) | < 0.001 |
Subscapular skinfold z-score | −0.01(0.8) | 0.2(0.7) | −0.3(0.8) | < 0.001 |
missing n(%) | 29(7.0) | 16(6.3) | 13(8.2) | |
Triceps skinfold z-score | 0.2(0.7) | 0.3(0.6) | −0.1(0.7) | < 0.001 |
missing n(%) | 25(6.1) | 15(5.9) | 10(6.3) | |
BMI-for-sex-and-age z-score | 0.1(1.0) | 0.2(1.0) | 0.1(0.9) | 0.499 |
missing n(%) | 2(0.4) | 0(0) | 2(1.3) | |