Assessment of Canadian Cree infants' birth size using the WHO Child Growth Standards

The WHO Child Growth Standards (CGS) which were recently adopted by the Canadian Pediatric Society were used to assess the relative size of Cree newborns.

Birth weight, length, and head circumference, and growth indices of 2,127 Cree newborns were compared with the CGS. Maternal characteristics of pregnancy and infant birth outcomes were recorded and stratified by birth weight category.

Among Cree newborns, 2.4% were low birth weight (LBW) (<2,500 g) and 36.5% were high birth weight (≥4,000 g). The median birth weight (g) for Cree male (4,030) and female (3,900) term newborns was higher than for male (3,346) and female (3,232) newborns of the CGS. Fewer than 1.5% of Cree infants had z-scores <-2SD from the WHO CGS median for BMI-for-age, length-for-age, weight-for-age, or head circumference-for-age whereas 4.6, 7.8, and 23.4% percent had z-scores >+2SD from the WHO CGS median for weight-for-length-for-age, BMI-for-age and head circumference-for-age, respectively. The majority (53.4%) of pregnancies was complicated by obesity and 10.3% were complicated by gestational diabetes mellitus (GDM). Infants weighing 4,000-4,499 g had a comparable prevalence of operative delivery (15.4%) as infants weighing 2,500-3,999 g (13.7%). Infants weighing ≥4,500 g had the highest prevalence of birth injuries (14.0%) and being born to women whose pregnancies were complicated by GDM (20%).

Cree newborns were larger than newborns of the CGS. The appropriateness for Cree infants of defining low and high birth weight from the WHO CGS is uncertain and may lead to inaccurate prognosis of postnatal health.