Archives of Disease in Childhood, 1978, 53, 731-736
Metabolic and endocrine events at the time of the first feed of human milk in preterm and term infants A. LUCAS, S. R. BLOOM, AND A. AYNSLEY-GREEN From the University Department ofPaediatrics, Oxford, and Hammersmith Hospital
The first feed of breast milk given to a group of 12 term infants was previously shown to increase the levels of blood glucose and plasma insulin, growth hormone (GH), gastrin, and enteroglucagon. We have now studied the effects of the first feed of breast milk in two similar groups of preterm infants, to compare the results with those obtained for the term infant. One group of 8 preterm infants received a bolus (2 * 5 ml/kg) of breast milk via a nasogastric tube; the other group of 5 infants received a continuous intragastric infusion (2 5 ml/kg per hour) of breast milk. No change occurred in the concentrations of blood glucose, lactate, pyruvate, or ketone bodies, or in plasma insulin, GH, pancreatic glucagon, or enteroglucagon in either the 'bolus fed' or the 'infusion fed' group of preterm infants. Thus the marked metabolic and endocrine changes in term infants after the first feed do not occur in pieterm infants with standard methods of feeding. SUMMARY
We have shown previously that term babies suffering from moderately severe respiratory distress show an increase in blood glucose, associated with a rise in plasma insulin, growth hormone (GH), gastrin, and enteroglucagon after the first feed (AynsleyGreen et al., 1977). This suggests that digestion and absorption, as well as several hormone systems, are functionally active at birth in the term infant. To define the metabolic and endocrine effects of standard feeding practices in the preterm infant, we measured blood levels of several metabolites and hormones before and after the first feed of breast milk in a group of infants fed by an intragastric bolus, and before and during the first feed in a group of infants fed by continuous intragastric infusion.
Patients and feeding procedure Patients. 15 preterm infants were studied with the approval of the ethical committee. The infants had been admitted to the special care baby unit because of prematurity. All had weights appropriate for gestational age. All had umbilical catheters in situ for clinical monitoring purposes. They were nursed either in incubators at environmental temperatures appropriate for their gestation and weight (Hey and Katz, 1970), or under radiant heaters with skin temperature servo controlled to 36.5 °C. At the time of the study no baby had a rectal temperature Received 18 January 1978
below 36'C. In all arterial pH was >7.20 throughout the study. Pao2 was maintained between 60 and 90 mmHg (8 and 12 kPa). One baby required resuscitation for apnoea 15 minutes after the first feed and was excluded from the study. The clinical condition of the remaining 14 infants did not change during the study. The infants were randomly divided into two groups, one receiving a bolus of breast milk and the other a continuous intragastric infusion of breast milk. In the bolus fed group, 8 infants were studied. The mean birthweight was 1290 g (range 960 to 1740 g), and the mean gestational age from maternal dates and paediatric assessment (Farr score) was 30 weeks (range 28 to 33 weeks). All 8 babies had respiratory distress, 7 requiring oxygen via a head box, one requiring assisted ventilation via an endotracheal tube. In the infusion fed group, 6 infants were initially studied, but one infant was excluded because he regurgitated his feed. The mean birthweight of the remaining 5 infants was 1520 g (range 1100 to 1770 g) and a mean gestational age of 30 weeks (range 28 to 32 weeks). 3 of the 5 babies had respiratory distress, requiring continuous positive airways pressure through an endotracheal tube. The 2 other infants had no respiratory problems.
Feeding procedure. The first feed was given between 3 and 6 hours of age. None of the infants had received intravenous dextrose. A nasogastric tube was inserted 731
732 Lucas, Bloom, and Aynsley-Green
into the stomach and the contents aspirated 30 minutes before the feed. The bolus fed infants received 2.5 ml/kg pooled boiled mature breast milk given by gravity for a 3-5-minute period via the nasogastric tube with the infant lying on the right side. Infusion fed infants received breast milk at a constant infusion rate of 2.5 ml/kg per hour via the nasogastric tube using a syringe pump. After 55 minutes, the end of the study period, the stomach contents were aspirated and in no case was more than 25 % of the original feed volume found to be present.
mmol/l (19±9 mg/100 ml) and 0-18±0-06 mmol/I (1-6 ± 0-53 mg/100 ml) respectively. These levels did not change with feeding. Table 1 shows the lactate and pyruvate levels with feeding in preterm babies, compared with the levels in term babies studied previously. 4-75 1
P
Metabolic and endocrine events at the time of the first feed of human milk in preterm and term infants A. LUCAS, S. R. BLOOM, AND A. AYNSLEY-GREEN From the University Department ofPaediatrics, Oxford, and Hammersmith Hospital
The first feed of breast milk given to a group of 12 term infants was previously shown to increase the levels of blood glucose and plasma insulin, growth hormone (GH), gastrin, and enteroglucagon. We have now studied the effects of the first feed of breast milk in two similar groups of preterm infants, to compare the results with those obtained for the term infant. One group of 8 preterm infants received a bolus (2 * 5 ml/kg) of breast milk via a nasogastric tube; the other group of 5 infants received a continuous intragastric infusion (2 5 ml/kg per hour) of breast milk. No change occurred in the concentrations of blood glucose, lactate, pyruvate, or ketone bodies, or in plasma insulin, GH, pancreatic glucagon, or enteroglucagon in either the 'bolus fed' or the 'infusion fed' group of preterm infants. Thus the marked metabolic and endocrine changes in term infants after the first feed do not occur in pieterm infants with standard methods of feeding. SUMMARY
We have shown previously that term babies suffering from moderately severe respiratory distress show an increase in blood glucose, associated with a rise in plasma insulin, growth hormone (GH), gastrin, and enteroglucagon after the first feed (AynsleyGreen et al., 1977). This suggests that digestion and absorption, as well as several hormone systems, are functionally active at birth in the term infant. To define the metabolic and endocrine effects of standard feeding practices in the preterm infant, we measured blood levels of several metabolites and hormones before and after the first feed of breast milk in a group of infants fed by an intragastric bolus, and before and during the first feed in a group of infants fed by continuous intragastric infusion.
Patients and feeding procedure Patients. 15 preterm infants were studied with the approval of the ethical committee. The infants had been admitted to the special care baby unit because of prematurity. All had weights appropriate for gestational age. All had umbilical catheters in situ for clinical monitoring purposes. They were nursed either in incubators at environmental temperatures appropriate for their gestation and weight (Hey and Katz, 1970), or under radiant heaters with skin temperature servo controlled to 36.5 °C. At the time of the study no baby had a rectal temperature Received 18 January 1978
below 36'C. In all arterial pH was >7.20 throughout the study. Pao2 was maintained between 60 and 90 mmHg (8 and 12 kPa). One baby required resuscitation for apnoea 15 minutes after the first feed and was excluded from the study. The clinical condition of the remaining 14 infants did not change during the study. The infants were randomly divided into two groups, one receiving a bolus of breast milk and the other a continuous intragastric infusion of breast milk. In the bolus fed group, 8 infants were studied. The mean birthweight was 1290 g (range 960 to 1740 g), and the mean gestational age from maternal dates and paediatric assessment (Farr score) was 30 weeks (range 28 to 33 weeks). All 8 babies had respiratory distress, 7 requiring oxygen via a head box, one requiring assisted ventilation via an endotracheal tube. In the infusion fed group, 6 infants were initially studied, but one infant was excluded because he regurgitated his feed. The mean birthweight of the remaining 5 infants was 1520 g (range 1100 to 1770 g) and a mean gestational age of 30 weeks (range 28 to 32 weeks). 3 of the 5 babies had respiratory distress, requiring continuous positive airways pressure through an endotracheal tube. The 2 other infants had no respiratory problems.
Feeding procedure. The first feed was given between 3 and 6 hours of age. None of the infants had received intravenous dextrose. A nasogastric tube was inserted 731
732 Lucas, Bloom, and Aynsley-Green
into the stomach and the contents aspirated 30 minutes before the feed. The bolus fed infants received 2.5 ml/kg pooled boiled mature breast milk given by gravity for a 3-5-minute period via the nasogastric tube with the infant lying on the right side. Infusion fed infants received breast milk at a constant infusion rate of 2.5 ml/kg per hour via the nasogastric tube using a syringe pump. After 55 minutes, the end of the study period, the stomach contents were aspirated and in no case was more than 25 % of the original feed volume found to be present.
mmol/l (19±9 mg/100 ml) and 0-18±0-06 mmol/I (1-6 ± 0-53 mg/100 ml) respectively. These levels did not change with feeding. Table 1 shows the lactate and pyruvate levels with feeding in preterm babies, compared with the levels in term babies studied previously. 4-75 1
P
