An updated reference for age-sex-specific birth weight percentiles stratified for ethnicity based on data from all live birth infants between 2005 and 2014 in Alberta, Canada

Reference Values for Birth Weight in Relation to Gestational Age in Poland and Comparison with the Global Percentile Standards

INTRODUCTION

Percentiles of birth weight by gestational age (GA) are an essential tool for clinical assessment and initiating interventions to reduce health risks. Unfortunately, Poland lacks a reference chart for assessing newborn growth based on the national population. This study aimed to establish a national reference range for birth weight percentiles among newborns from singleton deliveries in Poland. Additionally, we sought to compare these percentile charts with the currently used international standards, INTERGROWTH-21 and WHO.

MATERIALS AND METHODS

All singleton live births (n = 3,745,239) reported in Poland between 2010 and 2019 were analyzed. Using the Lambda Mu Sigma (LMS) method, the Generalized Additive Models for Location Scale, and Shape (GAMLSS) package, smoothed percentile charts (3-97) covering GA from 23 to 42 weeks were constructed.

RESULTS

The mean birth weight of boys was 3453 ± 540 g, and this was higher compared with that of girls (3317 ± 509 g). At each gestational age, boys exhibited higher birth weights than girls. The weight range between the 10th and 90th percentiles was 1061 g for boys and 1016 g for girls. Notably, the birth weight of Polish newborns was higher compared to previously published international growth standards.

CONCLUSION

The reference values for birth weight percentiles established in this study for Polish newborns differ from the global standards and are therefore useful for evaluating the growth of newborns within the national population. These findings hold clinical importance in identifying neonates requiring postbirth monitoring.

Birth Size and Maternal, Social, and Environmental Factors in the Province of Jujuy, Argentina

INTRODUCTION

birth size is affected by diverse maternal, environmental, social, and economic factors.

AIM

analyze the relationships between birth size-shown by the indicators small for gestational age (SGA) and large for gestational age (LGA)-and maternal, social, and environmental factors in the Argentine province of Jujuy, located in the Andean foothills.

METHODS

data was obtained from 49,185 mother-newborn pairs recorded in the Jujuy Perinatal Information System (SIP) between 2009 and 2014, including the following: newborn and maternal weight, length/height, and body mass index (BMI); gestational age and maternal age; mother's educational level, nutritional status, marital status and birth interval; planned pregnancy; geographic-linguistic origin of surnames; altitudinal place of birth; and unsatisfied basic needs (UBN). The dataset was split into two groups, SGA and LGA, and compared with adequate for gestational age (AGA). Bivariate analysis (ANOVA) and general lineal modeling (GLM) with multinomial distribution were employed.

RESULTS

for SGA newborns, risk factors were altitude (1.43 [1.12-1.82]), preterm birth (5.33 [4.17-6.82]), older maternal age (1.59 [1.24-2.05]), and primiparous mothers (1.88 [1.06-3.34]). For LGA newborns, the risk factors were female sex (2.72 [5.51-2.95]), overweight (1.33 [1.22-2.46]) and obesity (1.85 [1.66-2.07]).

CONCLUSIONS

the distribution of birth size and the factors related to its variability in Jujuy are found to be strongly conditioned by provincial terrain and the clinal variation due to its Andean location.