Impact of intra- and extrauterine growth on bone mineral density and content in the neonatal period of very-low-birth-weight infants

Measurement of Calprotectin and PTH in the Amniotic Fluid of Early Second Trimester Pregnancies and Their Impact on Fetuses with Growth Disorders: Are Their Levels Related to Oxidative Stress?

Background: During the early stages of human fetal development, the fetal skeleton system is chiefly made up of cartilage, which is gradually replaced by bone. Fetal bone development is mainly regulated by the parathyroid hormone parathormone (PTH) and PTH-related protein, with specific calprotectin playing a substantial role in cell adhesion and chemotaxis while exhibiting antimicrobial activity during the inflammatory osteogenesis process. The aim of our study was to measure the levels of PTH and calprotectin in early second trimester amniotic fluid and to carry out a comparison between the levels observed among normal full-term pregnancies (control group) and those of the groups of embryos exhibiting impaired or enhanced growth. Methods: For the present prospective study, we collected amniotic fluid samples from pregnancies that underwent amniocentesis at 15 to 22 weeks of gestational age during the period 2021-2023. Subsequently, we followed up on all pregnancies closely until delivery. Having recorded fetal birthweights, we then divided the neonates into three groups: small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA). Results: In total, 64 pregnancies, including 14 SGA, 10 LGA, and 40 AGA fetuses, were included in our study. Both substances were detected in early second trimester amniotic fluid in both groups. Concentrations of calprotectin differed significantly among the three groups (p = 0.033). AGA fetuses had a lower mean value of 4.195 (2.415-6.425) IU/mL, whereas LGA fetuses had a higher mean value of 6.055 (4.887-13.950) IU/mL, while SGA fetuses had a mean value of 5.475 (3.400-9.177) IU/mL. Further analysis revealed that only LGA fetuses had significantly higher calprotectin concentrations compared to AGA fetuses (p = 0.018). PTH concentration was similar between the groups, with LGA fetuses having a mean value of 13.18 (9.51-15.52) IU/mL, while SGA fetuses had a mean value of 14.18 (9.02-16.00) IU/mL, and AGA fetuses had similar concentrations of 13.35 (9.05-15.81) IU/mL. The differences in PTH concentration among the three groups were not statistically significant (p = 0.513). Conclusions: Calprotectin values in the amniotic fluid in the early second trimester were higher in LGA fetuses compared to those in the SGA and AGA categories. LGA fetuses can possibly be in a state of low-grade chronic inflammation due to excessive fat deposition, causing oxidative stress in LGA fetuses and, eventually, the release of calprotectin. Moreover, PTH concentrations in the amniotic fluid of early second trimester pregnancies were not found to be statistically correlated with fetal growth abnormalities in either LGA or SGA fetuses. However, the early time of collection and the small number of patients in our study should be taken into account.

Bone Status and Early Nutrition in Preterm Newborns with and without Intrauterine Growth Restriction

Intrauterine growth restriction (IUGR) together with preterm birth could be harmful to bone health. The aim of the study was to examine bone status in IUGR versus non-IUGR preterms and to analyze the nutritional management best correlated with its improvement. Newborns < 34 weeks of gestational age (wGA), 75 IUGR and 75 non-IUGR, admitted to the Neonatal Intensive Care Unit of the University Hospital of Padova were enrolled and monitored from birth until 36 wGA through anthropometry (weight, length, head circumference, lower limb length (LLL)), biochemistry, bone quantitative ultrasound assessment of bone status (metacarpus bone transmission time, mc-BTT, us) and nutritional intakes monitoring during parenteral nutrition. IUGR compared to non-IUGR showed lower mean mc-BTT (0.45 vs. 0.51, p = 0.0005) and plasmatic phosphate (1.45 vs. 1.79, p < 0.001) at birth. Mc-BTT at 36 wGA, though equal between groups, correlated in IUGR newborns with basal phosphate, mean total energy of the first week and month (positively) and days to reach full enteral feeding (negatively). Lower i.v. vitamin D intake, LLL and prolonged total parenteral nutrition predicted worse mc-BTT at 36 wGA in the enrolled infants. These results suggest that preterms and in particular IUGR newborns need special nutritional care to promote bone development.

Comorbidities in childhood associated with extrauterine growth restriction in preterm infants: a scoping review

Extrauterine growth restriction (EUGR) is a frequent morbidity of preterm infants that can affect short- and long-term prognosis as it involves different EUGR-related alterations in growth and neurological development, as well as cardiometabolic risk. However, knowledge about the prognosis of EUGR is scarce. Thus, the objective of this study is to review the evidence regarding EUGR-related comorbidities in childhood by a systematic approach. This review was carried out using the Joanna Briggs Institute Reviewers' Manual Methodology and the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses)-Search Extension for scoping review. The MEDLINE and EMBASE databases were used to identify papers published until September 2017. Twenty-four publications were included and 19 examined cohort studies. EUGR is mainly associated with (1) lower weight, length, and head circumference measures in childhood; (2) poor neurodevelopment; and (3) alterations in cardiometabolic risk markers. The definition for EUGR and the populations studied differ among authors.Conclusion: EUGR is mainly associated with poor growth and neurodevelopment, as well as with cardiometabolic alterations in childhood. Evidence is based on observational studies with variability in the included populations due to the lack of consensus regarding the definition for EUGR. Finding a gold standard definition becomes paramount in order to select phenotypes at risk later in life. What is known? • EUGR is a frequent condition of preterm infants. Up to date little is known about the effect of the metabolic programming on prognosis. What is new? • The available evidence, which is based on observational studies with variability in the population and the existing different definitions for EUGR, do not enable appropriate data collection. EUGR is mainly associated with poor growth and neurodevelopment, as well as with cardiometabolic alterations in childhood.