A modified cows' milk formula suitable for low birthweight infants.

Low birthweight babies fed standard modified cows' milk formulae are at risk from the high fluid intake needed for adequate nutrition, and very preterm babies often develop late hyponatraemia if the sodium intake fails to match large renal losses. A new cows' milk formula (Cow and Gate Prematalac) provides 120 kcal, 3.6 g protein, 7.5 g fat, and 4 mmol sodium in 150 ml. Ten low birthweight babies were fed the new formula at 150 ml/kg a day and compared with 12 similar babies fed a standard modified cows' milk formula (Wyeth SMA Gold Cap) at 180 ml/kg a day. All the babies grew at intrauterine rates and there was no difference in clinical course. None fed the new formula developed hypernatraemia, oedema, or dehydration and none fed the standard formula developed hyponatraemia. The Prematalac group safely excreted the increased osmotic load and had a higher urinary sodium concentration which should protect less mature preterm infants from late hyponatraemia.