Minipuberty in Male Full-term Neonates Appropriate and Small for Gestational Age and in Preterm Babies: Data from a Single Centre

Objective

The postnatal activation of the hypothalamic-pituitary-gonadal (HPG) axis is usually known as “minipuberty”. There are still open questions about its biological function and significance depending on sex, gestational age (GA) and birth weight (BW) with few available longitudinal data.

Methods

A single-centre, longitudinal study to quantify urinary follicle stimulating hormone (uFSH), luteinizing hormone (uLH) and testosterone (uTs) in male neonates. Neonates were enrolled and stratified into three subgroups: full-term boys appropriate for GA (FT AGA); FT boys with BW ≤3rd centile [FT small for gestational age (SGA)]; and preterm (PT) boys ≤33 weeks of GA. Urinary hormones were correlated to simultaneous auxological parameters, linear growth and external genitalia at scheduled time-points.

Results

Forty-six boys were recruited, with subgroup sizes FT AGA n=23, FT SGA n=11 and PT n=12. PT boys display a pulsatile pattern of urinary gonadotropins (uGns) with higher levels of uLH and a gradual increase of uTs. Testicular descent started from 29-32 weeks with the peak of uTs. During the first 12-months post-term age (PTA), FT AGA boys displayed a better linear growth (p<0.05). PT showed higher uGns levels until 3-months PTA. PT babies had higher uLH levels than FT AGA, with a peak at 7 and 30 days, during the first 90 days of life (p<0.001) and higher uTs levels. Correlation analysis between penile growth of all neonates and uTs was significant (p=0.04) but not within subgroups.

Conclusion

This study investigated postnatal HPG axis activation in term and PT infants. Minipuberty may involve an early window of opportunity to evaluate the functionality of the HPG axis. Further studies with a long-term follow-up are needed with a special focus on possible consequences of GA and BW.

Antibiotic Exposure, Common Morbidities and Main Intestinal Microbial Groups in Very Preterm Neonates: A Pilot Study

Prematurity exposes newborns to increased risks of infections and it is associated with critical morbidities. Preterm infants often require antibiotic therapies that can affect the correct establishment of gut microbiota. The aim of this study was to investigate targeted intestinal bacteria in preterm neonates with common morbidities and receiving antibiotic treatments of variable duration. Stool samples were collected after birth, at 15, 30 and 90 days of life. qPCR quantification of selected microbial groups (Bifidobacterium spp., Bacteroides fragilis group, Enterobacteriaceae, Clostridium cluster I and total bacteria) was performed and correlation between their levels, the duration of antibiotic treatment and different clinical conditions was studied. An increasing trend over time was observed for all microbial groups, especially for Bifdobacterium spp. Prolonged exposure to antibiotics in the first weeks of life affected Clostridium and B. fragilis levels, but these changes no longer persisted at 90 days of life. Variations of bacterial counts were associated with the length of hospital stay, feeding and mechanical ventilation. Late-onset sepsis and patent ductus arteriosus reduced the counts of Bifidobacterium, whereas B. fragilis was influenced by compromised respiratory conditions. This study can be a start point for the identification of microbial biomarkers associated with some common morbidities and tailored strategies for a healthy microbial development.

Heart failure caused by VGAM: a lesson for diagnosis and treatment from a case and literature review

We describe the case of a neonate with signs of heart failure. Echocardiography showed a structural normal heart shape with left ventricular dysfunction. At 2 months of age, a vein of Galen arteriovenous malformation was diagnosed through a brain magnetic resonance imaging. Embolization therapy was accomplished and a clinical and neurological follow-up was started. This clinical case highlights how important it is considering an intracranial cause in the differential diagnosis of neonatal congestive heart failure (CHF). We performed a narrative minireview of the literature about treatments and outcome of this malformation in association to CHF, to point out how complex the diagnosis of vein of Galen aneurysmal malformation (VGAM) may be and how an early diagnosis is important for its management.

Changes of intestinal microbiota in early life

There is an increasing evidence that the intestinal microbiota plays a pivotal role in the maturation of the immune system and in the prevention of diseases occurring during the neonatal period, childhood, and adulthood. A number of nonphysiological conditions during the perinatal period (i.e. caesarean section, prolonged hospitalization, formula feeding, low gestational age) may negatively affect the normal development of the microbiota, leading to decreased amounts of lactobacilli and bifidobacteria and increased amounts of Clostridia. In addition, perinatal antibiotics can cause intestinal dysbiosis that has been associated with short- and long-term diseases. For example, prolonged early empiric antibiotics increase the risk of necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) in preterm neonates, whereas the administration of intrapartum antibiotic prophylaxis (IAP) has been associated with inflammatory bowel diseases, obesity, and atopic conditions, such as eczema and wheezing. Promoting breastfeeding, reducing the length of hospital stay, and reducing unnecessary antibiotic therapies are useful strategies to counterbalance unintended effects of these conditions.