Table 2 Included studies on maternal obesity and initiation of breastfeeding

Donath & Amir 2000 [13], Australia, 1992–95

1995 National Health Survey

Children up to years 4 old n = 2612

BMI calculated from self-reported height and weight at time of interview

WHO definition of obesity

% (95% CI)

Underweight 89.0 (85.8, 92.2)

Normal weight 89.2 (87.4, 91.0)

Overweight 86.9 (84.0, 89.9)

Obese 82.3 (77.6, 87.0)

OR* overweight 1.25

OR* obese 1.78

Grjibovski et al 2005 [43], Severodvinsk, Russia, 1999

Antenatal community-based cohort n = 1078

Pre-pregnancy weight defined as under- normal and over-weight based on "doctor's diagnosis" [82]

Underweight 98.3%

Normal 98.7%

Overweight 100.0%

NS

Hilson et al 1997 [12]

Cooperstown, NY, USA, 1992–94

Medical record review Eligibility: intended to bf (= bf at birth), healthy singleton infant n = 1109

IOM definition of obesity

BMI calculated from pre-pregnancy weight and height

Quit bf by hospital discharge 2 d after birth:

Normal 4.3%

Overweight 8.9%

Obese 12.2%

OR* overweight 2.17

OR* obese 3.09

Not bf at discharge (of women who attempted bf at birth): Odds Ratio

Overweight 2.54 (p < 0.05)

Obese 3.65 (p = 0.0007)

Hilson et al 2006 [39] Cooperstown, NY, USA, 1988–97

Expanded previous review of medical records [12]

Eligibility: intended to bf (= bf at birth), singleton infant, no contraindications to bf, no diabetes n = 2783

IOM definition of obesity

BMI calculated from pre-pregnancy weight and height

Breastfeeding at 4 days:

Underweight 89.0%

Normal 90.1%

Overweight 88.4%

Obese 82.58%

Obese women different from underweight and normal

weight women

OR* overweight 1.19

OR* obese 1.92

Kugyelka et al 2004 [40] upstate New York, 1999–2000

Medical record review, including paediatric record to 6 months of age, all women of 'Hispanic ethnicity' (n = 235) or 'Black race' (n = 263) Eligibility: healthy mothers (BMI > 19) with healthy single, term infant, who attempted to breastfed

IOM definition

BMI calculated from pre-pregnancy weight and height

Baby put to breast < 2 h:

Hispanic women: Black women

Normal 71.8% 75.1%

Overweight 66.7% 69.2%

Obese 61.5% 63.8%

(p < 0.05) (p < 0.05)

Fed formula only during last 5 feeds in hospital:

Hispanic women: Black women:

Normal weight 9.6% 5.1%

Overweight 12.2% 8.0%

Obese 12.4% 6.9%

Hispanic women

OR* overweight 1.48

OR* obese 1.50

Black women

OR* overweight 1.62

OR* obese 1.38

Multivariate analysis:

Hispanic women: obese OR 1.92 (95% CI 1.20, 3.08) of formula and breast in last 5 feeds before discharge compared to breast only

(adjusted for maternal age, education, parity, gestation, birth wt, smoking and birth)

Other groups

NS

Li et al 2002 [83] USA, 1988–1994

The Third National Health and Nutrition Survey (NHANES III), children aged 2 mo to 6 yrs n = 8765 94% response for these children; 99% data of bf available

BMI calculated from self-reported ht and wt at time of interview.

WHO definition of obesity

Ever breastfed:

Normal 58.1%

Overweight 46.4%

Obese 44.8%

OR* overweight 1.60

OR* obese 1.71

Li et al 2003 [49] USA, 1996–98

Pediatric Nutrition Surveillance System and the Pregnancy Nutrition Surveillance System, children aged < 5 years n = 51,329

BMI calculated from self-reported pre-pregnancy wt IOM definition of obesity

Obese women more likely to never breastfeed (p < 0.01)

OR 1.28 estimated from Figure 1

Oddy et al 2006 [44] Australia, 1989–1991

Western Australian Pregnancy Cohort Study.

Pregnant women recruited from King Edward Memorial Hospital, Perth, WA n = 1803

BMI calculated from pre-pregnancy weight and height (measured by research midwives)

WHO definition of obesity

Never breastfed:

Normal weight 8.2%

Overweight 11.4%

Obese women 12.4%

NS

OR* overweight 1.33

OR* obese 1.47

Scott et al 2006 [45] Australia, 2002–2003

2^nd Perth Infant Feeding Study, cohort of women recruited in hospital. n = 587

Measurement of maternal weight and height not reported

WHO definition of obesity

Any breastfeeding at hospital discharge:

Normal weight 95.6%

Overweight 91.5%

Obese 90.7%

OR 0.45 (95% CI 0.19, 1.09)

OR* overweight 2.02

OR* obese 2.23

Exclusive breastfeeding at hospital discharge:

Multivariate analysis, Adjusted OR (95% CI):

Normal weight 1 (ref)

Overweight 0.50 (0.28, 0.89)

Obese 0.63 (0.33, 1.20)

(adjusted for maternal age, smoking, marital status, occupation, country of birth, parity, antenatal classes, timing of infant feeding decision, delivery, birth weight, special care nursery, mothers' infant feeding attitude, fathers' infant feeding preference, grandmothers' infant feeding preference, whether grandmother had bf)

OR* overweight 2.00

OR* obese 1.59

Sebire et al 2001 [14] UK, 1989–1997

St Mary's Maternity Information system database, North West Thames region n = 325,395

BMI calculated from weight at antenatal booking

Normal BMI 20-<25

Moderately obese 25-<30

Very obese BMI > 30

(BMI < 20 = underweight - excluded from study)

Bf at hospital discharge:

Multivariate analysis, Adjusted OR (99% CI):

Normal weight 1 (ref)

Mod obese 0.86 (0.84, 0.88)

Very obese 0.58 (0.56, 0.60)

(adjusted for ethnic group, parity, age, history of hypertension, diabetes)

OR* overweight 1.16

OR* obese 1.72