Growth patterns by birth size of preterm children born at 24-29 gestational weeks for the first 3 years.

BACKGROUND: Concerns are prevalent about preterm infant long-term growth regarding plotting low on growth charts at discharge, stunting, underweight, high body fat and subsequent cardiometabolic morbidities. OBJECTIVES: To examine (a) longitudinal growth patterns of extremely and very preterm infants to 3 years corrected age (CA) (outcome), categorised by their birthweight for gestational age: small, appropriate and large for gestational age (SGA, AGA and LGA, respectively) (exposure); and (b) the ability of growth faltering (<-2 z-scores) to predict suboptimal cognitive scores at 3 years CA. METHODS: Post-discharge head, length, weight and weight-4-length growth patterns of the PreM Growth cohort study infants born <30 weeks and < 1500 g, who had dietitian and multi-disciplinary support before and after discharge, were plotted against the World Health Organization growth standard. Infants with brain injuries, necrotising enterocolitis and bronchopulmonary dysplasia were excluded. RESULTS: Of the included 405 infants, the proportions of infants with anthropometric measures > - 2 z-scores improved with age. The highest proportions <-2 z-scores for length (24.2%) and weight (24.0%) were at 36 gestational weeks. The proportion with small heads was low by 0 months CA (1.8%). By 3 years CA, only a few children plotted lower than -2 z-scores for length, weight-4-length and weight (<6%). After zero months CA, high weight-4-length and body mass index > + 2 z-scores were rare (2.1% at 3 years CA). Those born SGA had higher proportions with shorter heights (16.7% vs. 5.2%) and lower weights (27.8% vs. 3.5%) at 3 years CA compared to those born AGA. The ability of growth faltering to predict cognitive scores was limited (AUROC 0.42, 95% CI 0.39, 0.45 to 0.52, 95% CI 0.41, 0.63). CONCLUSIONS: Although children born <30 weeks gestation without major neonatal morbidities plot low on growth charts at 36 weeks CA most catch up to growth chart curves by 3 years CA.

Does the evidence support in utero influences on later health and disease? A systematic review of highly cited Barker studies on developmental origins.

The developmental origins of health and disease hypothesis proposes that early exposure to adverse conditions during fetal development and early life have strong detrimental consequences on long-term health and susceptibility to chronic diseases. We conducted a systematic review to critically appraise Barker's highest cited publications using the risk-of-bias assessment tool (ROBINS-I) and investigate effects of overadjustment by later body weight. Our findings revealed that all included studies displayed high risks of bias, with particular concerns regarding confounding (8/8), selection of reported results (8/8), classification of exposure (7/8), selection of participants (5/8) and high rates of missing data (ranged from 15 to 87%). Later body weight was over-adjusted in most (6/8) of the studies. As all studies displayed high bias risk due to confounding, missing data and overadjustment, evidence is insufficient to support causal relationships between low birthweight and adult disease, warranting caution in clinical application. PROTOCOL REGISTRATION: PROSPERO CRD42023433179.