Human milk H2O2 content: does it benefit preterm infants?

BackgroundHuman milk has a high content of the antimicrobial compound hydrogen peroxide (H2O2). As opposed to healthy full-term infants, preterm neonates are fed previously expressed and stored maternal milk. These practices may favor H2O2 decomposition, thus limiting its potential benefit to preterm infants. The goal of this study was to evaluate the factors responsible for H2O2 generation and degradation in breastmilk.MethodsHuman donors' and rats' milk, along with rat mammary tissue were evaluated. The role of oxytocin and xanthine oxidase on H2O2 generation, its pH-dependent stability, as well as its degradation via lactoperoxidase and catalase was measured in milk.ResultsBreast tissue xanthine oxidase is responsible for the H2O2 generation and its milk content is dependent on oxytocin stimulation. Stability of the human milk H2O2 content is pH-dependent and greatest in the acidic range. Complete H2O2 degradation occurs when human milk is maintained, longer than 10 min, at room temperature and this process is suppressed by lactoperoxidase and catalase inhibition.ConclusionFresh breastmilk H2O2 content is labile and quickly degrades at room temperature. Further investigation on breastmilk handling techniques to preserve its H2O2 content, when gavage-fed to preterm infants is warranted.

Gavage Feed Volume Determines the Gastric Emptying Rate in Preterm Infants.

OBJECTIVE: Feeding intolerance, manifesting as increased gastric residual, is a common finding in preterm neonates. Little is known about the regulation of gastric emptying early in life and the extent to which this plays a role in the preterm infants' feeding tolerance. The goal of this study was to evaluate clinically stable 28- to 32-week gestation neonates during the first 4 weeks of life and noninvasively determine their gastric emptying rate. STUDY DESIGN: Ultrasound measurements of gastric milk content volume were obtained from 25 neonates immediately after, 30 and/or 60 minutes following routine gavage feeds. The content emptying rate was calculated from the gastric volume data. RESULTS: Gastric emptying rate was not postnatal age-dependent, was significantly higher at 30 minutes, whenever compared with 60-minute postfeed and directly proportional to the feed volume. At any postnatal age, the gastric emptying rate was at least 6-fold greater, when comparing the lowest and highest average stomach content volumes. CONCLUSIONS: The gastric emptying rate of preterm infants is content volume-dependent and unrelated to the postnatal age. Given the present findings, further investigation on the gastric residual of preterm infants receiving larger than currently administered feed volumes at the initiation of enteral nutrition, is warranted.

Monozygotic twins discordant for Goldenhar syndrome.

OBJECTIVE: To report on a pair of monozygotic female twins discordant for Goldenhar syndrome. DESCRIPTION: The affected twin was a girl, who was delivered by caesarean section at 35 weeks' gestation. Her birth weight was 2,170 g, length 42.5 cm, head circumference 30 cm and her Apgar scores were 3/7. After birth the child developed severe respiratory distress and had to be moved to the neonatal intensive care unit (ICU). The other twin was a girl, born weighing 3,200 g with a length of 49 cm, head circumference of 34 cm and Apgar scores of 8/10. She was transferred to the mother-baby unit soon after birth and was discharged two days later. There was no consanguinity between the twins' parents, who were young and healthy at the time of their conception. The affected child's dysmorphic features included left hemifacial microsomia, severe micrognathia, abnormal ears, bilateral preauricular tags and epibulbar dermoid in the right eye. She developed obstructive apnea due to micrognathia and required tracheostomy. Abdominal and cranial ultrasound findings were normal, as was an ophthalmological assessment. Spine x-ray showed hemivertebra at T9 and T10. An echocardiogram showed Tetralogy of Fallot. GTG-banded karyotyping was performed on peripheral blood cells and revealed 46,XX. Zygosity testing established the pair of twins to be monozygotic with a probability greater than 99:1. COMMENT: Goldenhar syndrome was diagnosed in one of the twins described here. There are several reports of twins discordant for this disorder and therefore non-genetic factors may also play an important role, for instance vascular disruption during morphogenesis.

Monozygotic twins discordant for Goldenhar syndrome

OBJECTIVE: To report on a pair of monozygotic female twins discordant for Goldenhar syndrome. DESCRIPTION: The affected twin was a girl, who was delivered by caesarean section at 35 weeks' gestation. Her birth weight was 2,170 g, length 42.5 cm, head circumference 30 cm and her Apgar scores were 3/7. After birth the child developed severe respiratory distress and had to be moved to the neonatal intensive care unit (ICU). The other twin was a girl, born weighing 3,200 g with a length of 49 cm, head circumference of 34 cm and Apgar scores of 8/10. She was transferred to the mother-baby unit soon after birth and was discharged two days later. There was no consanguinity between the twins' parents, who were young and healthy at the time of their conception. The affected child's dysmorphic features included left hemifacial microsomia, severe micrognathia, abnormal ears, bilateral preauricular tags and epibulbar dermoid in the right eye. She developed obstructive apnea due to micrognathia and required tracheostomy. Abdominal and cranial ultrasound findings were normal, as was an ophthalmological assessment. Spine x-ray showed hemivertebra at T9 and T10. An echocardiogram showed Tetralogy of Fallot. GTG-banded karyotyping was performed on peripheral blood cells and revealed 46,XX. Zygosity testing established the pair of twins to be monozygotic with a probability greater than 99:1. COMMENT: Goldenhar syndrome was diagnosed in one of the twins described here. There are several reports of twins discordant for this disorder and therefore non-genetic factors may also play an important role, for instance vascular disruption during morphogenesis.