Background: Since growth patterns change with time due to secular changes, there is a need to regularly update growth references1. We developed the first continuous birth size reference, from gestational age 24weeks with infancy growth references2, computerized 2006 and used in Swedish health care settings and neonatal units. We now aimed to update this reference by exchanging GrowUp1974Gothenburg cohort to a selected population of healthy children of the GrowUp1990Gothenburg cohort, representing how infants optimally ought to growth.
Methods: To the present birth reference2 of healthy infants born 1990-99, from 24weeks of gestation (around 800.000, 76%, of all 1.053 425 born and documented in Swedish Medical Birth Registry), we mathematically merged with growth data from GrowUp1990Gothenburg cohort in exchange of growth data from previous GrowUp1974Gothenburg cohort3. Growth data from healthy children with longitudinal measurements for length: 1572(763 girls)4, weight: 1418(698 girls)5, and head circumference (HC): 1325(642 girls) were used. Individuals from GrowUp1990Gothenburg cohort used were born at term to non-smoking mothers, Nordic parents. New infancy references for HC (LMS-method. QE-method), length (QE-method), and weight (LMS-method) were constructed. From QEPS-height-model6, a QE-head-model was developed to construct QE-HC-references, first developed in the 1974-cohort with HC-measurements up to 4yrs, thereafter applied to the 1990-cohort 0-4yrs, resulting in a reference equal to the HC-reference constructed by LMS.
Results: Compared to the present birth-infancy 1974-reference 0-2yrs, the new birth-infancy 1990-references show the 1990-cohort for mean/median, +2SDS; -2SDS for: Length: to be 1 cm longer around 1yr of age with similar lengths at birth and around 2yrs of age for both sexes. Weight: median to be similar, with age somewhat lighter mostly at +2SDS. Head circumference: (LMS to 2yrs) to be 0.5 cm bigger at mean, 0.25 cm at +2SDS, +0.75 cm at -2SDS; (QE to 4yrs) to be 0.5-1 cm bigger with most fluctuations at -2SDS. A growth model-based HC-reference up to 4yrs was constructed.
Conclusion: A continuous reference bridging birth size with infancy growth of healthy infants born in the 90ies for head circumference, length, and weight was constructed. The references take gestational age into account for postnatal growth allowing for optimal identification of abnormal growth during the turbulent infancy period, important for present and future health.
1. Holmgren, A. Acta Paediatr.2022;111:225-35;
2. Niklasson, A&Albertsson-Wikland, K. BMC Pediatr.2008,8:8. doi:10.1186/1471-2431-8-8;
3. Albertsson-Wikland, K, et al. Acta Paediatr.2002;91:739-54
4. Albertsson-Wikland, K, et al. Acta Paediatr.2020;109:754-63
5. Albertsson-Wikland, K, et al. Acta Paediatr.2021;110:537-48
6. Nierop, AF, et al. J.Theor.Biol.2016;406:143-65
15 Sep 2022 - 17 Sep 2022