Quantitative ultrasound (QUS): a useful tool for monitoring bone health in preterm infants?

UNLABELLED: Preterm infants are at risk of osteopenia and metabolic bone disease (MBD) of prematurity. There is a need for simple, reliable methods to detect and monitor this condition. AIMS: The aims were first to describe longitudinal changes in speed of sound (SOS) measured using quantitative ultrasound (QUS; Sunlight Omnisense, Israel) in preterm neonates: and second to determine whether SOS predicts the development of MBD. METHODS: SOS was measured in the tibia in 99 preterm infants (mean (SD)) gestation 29.7 (3.6) weeks; birthweight 1340 (550) g, with longitudinal measurements in 75. SOS z-scores were generated for gestation and sex. Clinical data were recorded. RESULTS: Baseline SOS (but not SOS z-score) was positively associated with gestational age. SOS and SOS z-score fell with age. In multivariate models, peak ALP, minimum phosphate concentrations and markers of illness severity were not predictors of the fall in SOS z-score, and baseline SOS measurements did not predict the development of high peak ALP or low phosphate. INTERPRETATION: Speed of sound measurements fell with age in all infants, but we found no evidence that this measurement could predict biochemical indicators of MBD. We cannot exclude the possibility that this technique could be useful in monitoring the response to interventions designed to improve bone health in this population.

Randomised, double blind trial of oxytocin nasal spray in mothers expressing breast milk for preterm infants.

BACKGROUND: Human milk has considerable short and long term benefits for preterm infants, but mothers may experience difficulties in expressing breast milk for infants too immature or sick to breast feed. Oxytocin has been used to assist breast feeding and milk expression, but few data are available to support this intervention in the neonatal unit setting. AIM: To test the hypothesis that oxytocin nasal spray increases early milk output in mothers expressing milk for preterm infants. METHODS: A randomised, double blind trial of oxytocin nasal spray (100 microl per dose) versus placebo was conducted in mothers delivering infants <35 weeks gestation. Sprays were used before expression of milk using an electric pump up to day 5. MAIN OUTCOME: Total weight of milk expressed while using spray (study powered to detect >1SD difference between groups). SECONDARY OUTCOMES: Pattern of milk production; number of pumping sessions; weight/fat content of milk expressed during a fixed 20 minute period on day 5 ("physiological study"); mother's opinion of expressing and spray assessed by questionnaire. RESULTS: Fifty one mothers were randomised (27 oxytocin, 24 placebo). Total milk production did not differ between groups. Repeated measures analysis of variance suggested significantly (p = 0.001) different patterns of milk production, with initial faster production in the oxytocin group then convergence between groups. Parity did not influence the response to the intervention. No significant differences were seen in milk weight or fat content in the physiological study nor in mothers' opinions of milk expression and treatment. CONCLUSIONS: Despite marginal differences in the pattern of early milk production, the use of oxytocin nasal spray did not significantly improve outcome. Most mothers believed they were receiving the active spray, suggesting a significant placebo effect (supported by limited data from historical controls) and benefits from the extra breast feeding support available during the study.