Babies born preterm (before 37 completed weeks of gestation) have a higher energy requirement than babies born full term and therefore fail to gain weight adequately. Parents of preterm babies and doctors alike are not sure whether breast milk or formula milk alone will meet the energy requirements after the first four months and whether preterm babies should be started on complementary food. While normal babies are given solids and semi-solids only from six months of age, early initiation of complementary food, which has a higher calorie density, in preterm babies appears to be a good idea to meet their energy needs and improve their growth (weight and length).
Till recently there was little evidence of whether earlier introduction of complementary feeding (prior to six months of corrected age) would improve growth of preterm babies.
No gain in growth
A study published a few days ago in The Lancet Global Health has found an answer to this vexatious issue — early initiation of complementary feeding in preterm babies born before 34 weeks of gestation does not improve growth.
Doctors from the All India Institute of Medical Sciences (AIIMS), Safdarjung Hospital and Kasturba Hospital, all in New Delhi, enrolled 403 babies born before 34 weeks of gestation and randomly assigned them to two groups — one in which they were started on complementary feeding at four months of corrected age and the other group of babies where complementary feeding was initiated at six months of corrected age. The corrected age refers to age that is corrected for the period of prematurity — for a baby born at 32 weeks of gestation, which is approximately two months earlier than the normal gestation period, the corrected age is 10 months at the end of one year of birth.
Complementary feeding was standardised in both the groups in terms of frequency, consistency, type of food, preparing food hygienically, and ways of feeding. Complementary foods were given in addition to breastfeeding/other milk feeding.
“Even though one group of babies was started on complementary feeding at an earlier age of four months of corrected age, there was no difference in growth compared with babies who were started on complementary feeding at six months of corrected age,” says Dr. Ramesh Agarwal from the Department of Paediatrics at AIIMS, one of the corresponding authors of the paper.
Some health risks
On the other hand, the study indicates that early initiation of complementary feeding had some negative fallout. “There were more hospitalisations in the group that started on complementary feeding at four months of corrected age,” he says. Though overall hospital admission in both the groups was low, babies in the four-month group were at increased risk of hospital admission due to diarrhoea and lower respiratory tract infections. “There could be several reasons for this increased risk, including potential contamination of complementary foods due to inadequate hygiene or having less breast milk,” he says.
“Our study shows that there is no difference in growth whether complementary feeding is started at four or six months of corrected age. But there are more infections when complementary feeding is started earlier. So it is advisable that complementary feeding is started only at six months of corrected age in preterm babies less than 34 weeks of gestation,” says Dr. Agarwal. However, studying the difference in growth and not infection was the primary objective of the study.