Background: Experts recommend assessing preterm infant growth against fetal growth patterns. However, obtaining accurate estimates of healthy fetal growth from preterm infants is challenging as many had intrauterine faltering growth.Objectives: To improve preterm infant growth assessments by developing Fenton third‐generation sex‐specific preterm growth charts based on anthropometric distributions of preterm infants without abnormal fetal growth. We also aimed to evaluate the consistency of the new charts' growth velocities.Data Sources: From the last search for the 2013 Fenton growth charts to November 2024, MEDLINE and EMBASE databases, grey literature, as well as US Vital statistics and iNeo Consortium.Study Selection and Data Extraction: We followed systematic review methodology to identify population‐based sex‐specific anthropometric estimates of preterm cohorts without abnormal fetal growth beginning ≤ 24 weeks of gestation. Specified a priori, outcomes included newborn sex‐specific estimates of birthweight, length, and head circumference.Synthesis: We followed PRISMA guidelines. Literature screening and quality assessment were performed in duplicate. We harmonised weight, length, and head circumference weighted‐average meta‐analyses with the World Health Organization growth standard and rescaled the charts' x‐axis from completed gestational weeks to exact gestational age (weeks and days).Results: Seven studies from 15 countries (Australia, Brazil, Canada, China, Finland, Israel, Italy, Japan, Netherlands, New Zealand, Sweden, Switzerland, Spain, United Kingdom and United States) were included, representing 4.8 million births 22–42 weeks of gestation. 174,184 were < 30 weeks gestational age. The Fenton third‐generation preterm growth charts' weights showed improved growth velocity across percentiles with consistent declines for weight, length and head circumference velocity as post‐menstrual age increased. The birthweight meta‐analysis curves had similar shapes to fetal ultrasound estimates.Conclusions: The Fenton third‐generation preterm infant growth chart curves demonstrate improved and more uniform slopes across percentiles and closer alignment with fetal ultrasound estimates, offering a growth standard for preterm infants.Prospero Registration: CRD42024589756

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 ( + 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.

Background: Overweight and obesity and their consequent morbidities are important worldwide health problems. Some research suggests excess adiposity origins may begin in fetal life, but unknown is whether this applies to infants born preterm.Objective: The objective of the study was to assess the association between small for gestational age (SGA) birth and later adiposity and height among those born preterm.Data sources: MEDLINE, EMBASE and CINAHL until October 2022.Study selection and data extraction: Studies were included if they reported anthropometric (adiposity measures and height) outcomes for participants born preterm with SGA versus non‐SGA. Screening, data extraction and risks of bias assessments were conducted in duplicate by two reviewers.Synthesis: We meta‐analysed across studies using random‐effects models and explored potential heterogeneity sources.Results: Thirty‐nine studies met the inclusion criteria. In later life, preterm SGA infants had a lower body mass index (−0.66 kg/m², 95% CI −0.79, −0.53; 32 studies, I² = 16.7, n = 30,346), waist circumference (−1.20 cm, 95% CI −2.17, −0.23; 13 studies, I² = 19.4, n = 2061), lean mass (−2.62 kg, 95% CI −3.45, 1.80; 7 studies, I² = 0, n = 205) and height (−3.85 cm, 95% CI −4.73, −2.96; 26 studies, I² = 52.6, n = 4174) compared with those preterm infants born non‐SGA. There were no differences between preterm SGA and preterm non‐SGA groups in waist/hip ratio, body fat, body fat per cent, truncal fat per cent, fat mass index or lean mass index, although power was limited for some analyses. Studies were rated at high risk of bias due to potential residual confounding and low risk of bias in other domains.Conclusions: Compared to their preterm non‐SGA peers, preterm infants born SGA have lower BMI, waist circumference, lean body mass and height in later life. No differences in adiposity were observed between SGA preterm infants and non‐SGA preterm infants.

Objective: To evaluate the effect of age correction up to 36 months of age for growth assessments of extremely preterm (<28 weeks) and very preterm (28 to <32 weeks) infants. Study Design: This longitudinal analysis used data from the Preterm Infant Multicenter Growth Study (2001–2014). Results: 1,416 children were included (Median gestational age = 27 weeks). Chronological age-based weight, height, and head circumference z-scores were consistently lower than those based on corrected age for all ages (0, 4, 8, 21 and 36 months) by up to −5.2 (95% confidence interval −5.4, −5.1) z-scores for length at term. Using chronological age, higher proportions of children were misclassified as having suboptimal growth (up to 72.9% misdiagnosed as stunted and 89.8% misdiagnosed as underweight at term). Conclusion: For extremely and very preterm children, age correction is required for all growth measures through 36 months of corrected age.