Table 3 Hazard ratio of developing T2D in women with GDM according to duration of exclusive breastfeeding, maternal age, parity, deprivation category, BMI and family history

Latest point baby exclusively breastfeeding (total n = 1, 378)

None (n = 585)

154 (26.3)

67.6

1.44 (0.98–2.12)

0.065

1.49 (0.86–2.58)

0.151

At Birth (n = 209)

56 (26.8)

54.0

1.76 (1.13–2.74)

0.012

2.20 (1.21-4.00)

0.010

At Discharge (n = 399)

74 (18.5)

68.5

1.20 (0.79–1.83)

0.399

1.70 (0.95–3.03)

0.075

At midwife visit (n = 3)

0 (0)

0

0.0 (0.0–0.0)

0.935

0.0 (0.0–0.0)

0.958

At 2 weeks (n = 71)

26 (36.6)

73.8

1.22 (0.72–2.05)

0.459

1.81 (0.91–3.60)

0.089

At 8 weeks (n = 111)

31 (27.9)

77.6

1

1

Maternal age at delivery (total n = 2,458)

< 20 (n = 89)

14 (15.7)

69.5

1

1

20–24 (n = 278)

46 (16.5)

61.6

1.11 (0.61–2.03)

0.723

2.87 (0.39–21.15)

0.302

25–34 (n = 1322)

221 (16.7)

73.0

1.04 (0.61–1.78)

0.889

1.93 (0.27–13.96)

0.515

35 and over (n = 769)

108 (14.0)

76.2

0.95 (0.54–1.65)

0.847

1.92 (0.26–14.05)

0.520

Parity (total n = 2, 443)

Nulliparous (n = 991)

159 (16.0)

73.0

1

1

Multiparous (n = 1452)

230 (15.8)

71.7

1.06(0.87–1.3)

0.548

1.03 (0.77–1.37)

0.850

SIMD quintile (n = 1, 378)

1 (most deprived, n = 385)

116 (18.6)

65.2

1.78 (1.26–2.51)

< 0.001

2.69 (1.56–4.62)

< 0.001

2 (n = 306)

80 (16.3)

70.4

1.55 (1.08–2.24)

0.017

2.36 (1.34–4.15)

0.003

3 (n = 250)

59 (15.3)

60.2

1.51 (1.03–2.23)

0.036

1.81 (1.0-3.28)

0.051

4 (n = 239)

54 (15.3)

82.0

1.18 (0.80–1.75)

0.404

1.75 (0.98–3.14)

0.061

5 (least deprived, n = 198)

46 (13.7)

98.5

1

1

BMI (total n = 1,686)

Normal (210)

29 (13.8)

80

1

1

Overweight (332)

52 (15.7)

86.3

1.08 (0.68–1.70)

0.747

1.10 (0.65–1.85)

0.727

Obese (1135)

187 (16.5)

72.3

1.13 (0.76–1.67)

0.549

1.15 (0.73–1.79)

0.550

Family History of Diabetes (total n = 2, 484)

Yes (341)

122 (35.8)

88.4

1.88 (1.51–2.33)

< 0.001

1.77 (1.29–2.42)

< 0.001

No/Not recorded (2,143)

273 (12.7)

65.6

1

1