Comparison of singleton and twin birth weight reference percentile curves by gestational age and sex in extremely preterm infants: a population-based study.

BACKGROUND: With the increasing survival rate of smaller newborns and twins, previous growth curves may not accurately assess the growth of extremely preterm infants (EPIs). Our study aimed to establish birth weight percentile curves for singletons and twins in EPIs from China and the USA and compare the differences between them. METHODS: In China, EPIs were from 31 provinces, from 2010 to 2021. The collected information was sex, gestational age, birth weight, singletons and twins. We used the generalised additive models for location scale and shape method to construct the birth weight percentile curves by gestational age and sex for EPIs. The National Vital Statistics System database from 2016 to 2021 was also analysed. We compared the differences between the 50th birth weight percentile curves of the two databases. RESULTS: We identified 8768 neonates in China (5536 singletons and 3232 twins) and 121 933 neonates in the USA (97 329 singletons and 24 604 twins). We established the 3rd, 10th, 25th, 50th, 75th, 90th and 97th birth weight reference curves for China and the USA. The results showed that males had higher birth weights than females. In China, for the same gestational age and sex, birth weights in singletons and twins were found to be similar, though singleton males born in China had slightly higher birth weights than male twins. In the USA, birth weights were also similar for females and males, with the same gestational age in singletons and twins. CONCLUSION: We established birth weight reference percentile curves by gestational age and sex for singletons and twins among EPIs in China and the USA.

Paternal age, risk of congenital anomalies, and birth outcomes: a population-based cohort study.

The objective of the study was to explore the impact of paternal age on the risk of congenital anomalies and birth outcomes in infants born in the USA between 2016 and 2021. This retrospective cohort study used data from the National Vital Statistics System (NVSS) database, a data set containing information on live birth in the USA between 2016 and 2021. Newborns were divided into four groups based on their paternal age (< 25, 25-34, 35-44, and > 44 years) and using the 25-34 age group as a reference. The primary outcomes were congenital anomalies involving structural anomalies and chromosome anomalies. Secondary outcomes were preterm birth, low birth weight, severe neonatal perinatal asphyxia, and admission to neonatal intensive care units (NICU). A multivariable logistic regression model was used to analyze the association between paternal age and outcomes. Overall, 17,764,695 live births were included in the final analyses. After adjusting confounding factors, advanced paternal age > 44 years was associated with increased odds of congenital anomalies (adjusted odds ratio (aOR) = 1.17, 95%CI 1.12-1.21) compared with the 25-34 age group, mainly for the chromosomal anomalies (aOR = 1.59, 95%CI 1.40-1.78) but not the structure anomalies (aOR = 1.03, 95%CI 0.97-1.09). The risk of preterm delivery, low birth weight, and NICU hospitalization in their infants was increased by advanced parental age as well.  Conclusion: Advanced paternal age increases the risk of congenital anomalies, especially chromosomal anomalies in their offspring, implying prenatal genetic counseling is required. What is Known: • There's a rising trend of advanced paternal age, which is associated with an increased likelihood of premature birth and low birth weight in their offspring. However, the exploration between paternal age and congenital abnormalities in offspring was limited and contradictory. What is New: • Infants with a paternal age > 44 years were more likely to be born with congenital anomalies, especially chromosomal anomalies.

Effects of linezolid on the haematological system in very low birth weight infants: A single-centre retrospective study.

WHAT IS KNOWN AND OBJECTIVE: Linezolid, as a substitute for vancomycin, has been used in treating methicillin-resistant Gram-positive bacterial infections in very low birth weight (VLBW) infants. However, when linezolid induces thrombocytopenia in adults, its side effects in VLBW infants are concerning. This study aimed to investigate the effect of linezolid on haematologic profiles in this specific vulnerable population. METHODS: VLBW infants treated with linezolid from January, 2017, to July, 2021, were retrospectively analysed compared with vancomycin as controls. The effects of medications on haematologic parameters were compared on Days 1, 3, 5, 7, 10, 14 and 21 after medication initiation. RESULT AND DISCUSSION: Totally 40 VLBW infants treated with linezolid were recruited in the study, using 45 VLBW treated with vancomycin as controls. Baseline clinical characteristics, such as gestational age and birth weight, were not significantly different between the two groups. After medication initiation, the white blood cell counts on the Days 5 and 7 in the linezolid group were significantly lower than that in the vancomycin group (D5: 11.6 ± 6.2*109/L vs. 14.5 ± 6.4*109/L, p = 0.013; D7: 10.8 ± 5.9*109/L vs. 14.1 ± 8.0*109/L, p = 0.01), while the platelet counts were significantly lower in the linezolid group on Days 10 and 14 (D10: 219.2 ± 90.5*109/L vs. 287.5 ± 100.4*109/L, p = 0.049; D14: 263.0 ± 110.9*109/L vs. 325.0 ± 155.1*109/L, p = 0.036). For substantial haematologic abnormalities, there were no significant differences in leukopenia, neutropenia, agranulocytosis and thrombocytopenia between the two groups. WHAT IS NEW AND CONCLUSIONS: In VLBW infants, compared with vancomycin, linezolid tends to induce lower white blood cell and platelet counts transiently, but does not increase the severe forms of haematologic side effects.