Table 2 Associations between early-life exposures and timing of thelarche in the Sister Study cohort (N = 49,162)

Maternal pregnancy characteristics

Diabetes

 Any

458

1.20

0.93, 1.54

0.91

0.70, 1.17

  Gestational diabetes

215

0.79

0.52, 1.21

0.87

0.60, 1.25

  Pre-pregnancy diabetes

223

1.72

1.24, 2.38

0.88

0.60, 1.29

 None

43,594

1

Ref

1

Ref

Gestational hypertensive disorder

 Any

1709

1.25

1.09, 1.43

0.96

0.84, 1.10

  Pre-eclampsia

887

1.32

1.10, 1.58

0.99

0.83, 1.19

  Gestational hypertension

626

1.12

0.90, 1.40

0.80

0.64, 1.01

 None

35,299

1

Ref

1

Ref

DES use

 Yes

1142

1.23

1.04, 1.45

1.02

0.86, 1.19

 No

40,641

1

Ref

1

Ref

Smoking during pregnancy

 Yes

14,878

1.20

1.13, 1.27

1.02

0.97, 1.08

 No

31,875

1

Ref

1

Ref

Farm exposure

 Work and residence

5730

1.00

0.92, 1.09

0.94

0.87, 1.02

 Work only

627

1.06

0.84, 1.33

1.21

0.99, 1.48

 Residence only

2040

0.98

0.86, 1.12

0.86

0.76, 0.98

 None

39,169

1

Ref

1

Ref

Age at delivery

 < 20 years

2334

1.30

1.16, 1.47

0.93

0.82, 1.05

 20–24 years

11,512

1.09

1.01, 1.17

0.97

0.91, 1.03

 25–29 years

14,679

1

Ref

1

Ref

 30–34 years

11,208

0.95

0.88, 1.02

0.95

0.89, 1.01

 35–39 years

6414

0.99

0.90, 1.08

0.94

0.87, 1.02

 ≥ 40 years

2430

0.95

0.83, 1.08

1.00

0.89, 1.12

Birth and infancy characteristics

Firstborn

 Yes

11,294

1.25

1.17, 1.33

0.84

0.79, 0.89

 No

37,606

1

Ref

1

Ref

Birthweight

 < 2500 g

3729

1.06

0.96, 1.17

1.15

1.05, 1.25

 2500–3999 g

29,505

1

Ref

1

Ref

 ≥ 4000 g

3,338

1.00

0.90, 1.11

0.99

0.90, 1.09

Multiple birth

 Yes

1541

0.87

0.74, 1.02

1.11

0.98, 1.27

 No

47,614

1

Ref

1

Ref

Gestational age at birth

 Born ≥ 1 month before due date

990

0.91

0.75, 1.11

1.16

0.99, 1.37

 Born 2–4 weeks before due date

1904

1.06

0.92, 1.21

0.93

0.81, 1.06

 Not born ≥ 2 weeks before due date

19,940

1

Ref

1

Ref

Ever breastfed

 Yes

22,369

0.98

0.93, 1.04

0.95

0.90, 1.00

 No

23,116

1

Ref

1

Ref

Ever fed soy formula

 Yes

1195

1.10

0.93, 1.30

1.07

0.92, 1.25

 No

39,559

1

Ref

1

Ref