Auxologic, biochemical and clinical (ABC) profile of low birth weight babies- a 2-year prospective study

Abstract

Introduction: Low Birth Weight (LBW) is a key determinant of neonatal mortality, morbidity, subsequent growth and development as well as early onset of adulthood diseases. It represents a conflation of two outcomes-preterm- and term 'light for date' (LFD) babies. This study looks at key auxologic, biochemical and clinical (ABC) parameters of a cohort of LBW babies, both preterm- and term in comparison to a group of normal-term (control) babies. An attempt was also made to see how these parameters were at the end of a 2 year follow-up period with the currently available interventions.

Materials and methods: A cohort of 500 babies was selected at birth from a tertiary care teaching hospital in Kerala, India, key ABC indices were measured including relevant maternal data. The initial biochemical measurements were done using umbilical cord blood. Currently recommended nutritional interventions were provided to all the normal and LBW babies. At the end of 2 years, the measurements were repeated in a subset of babies available for follow-up (n = 147).

Results: From the cohort of 500 babies, two had to be eliminated as biochemical parameters could not be done due to technical reasons from the available umbilical cord blood. They were categorized into three groups: preterm-LBW (11.85%), term-LBW (38.55%) and normal-term controls (49.6%). The maternal characteristics like socio-economic status, maternal weight, height, BMI and hemoglobin levels were comparable in the three subsets. All of them belonged to middle or low-socio-economic status representing the non-affluent. In the initial group (n = 498), all the auxologic measurements and the nutrients measured namely, total protein, albumin, total cholesterol, triglycerides, calcium, magnesium, zinc and iron levels were significantly lower (p < 0.05) among LBW, lowest in preterm followed by term-LBW, compared to term controls. Total iron binding capacity showed inverse correlation with iron level. Protein, albumin, calcium and iron levels were low in many babies, and mean calcium and iron levels were below the normal range in all the three subsets reflecting reduced transfer from the mother. At the end of 2 years, calcium, magnesium, zinc and iron were significantly lower in preterm- and term-LBW (p < 0.05) compared to controls and mean value of serum calcium continued to be below the normal range in all the three subsets. At final follow-up, majority of the LBW babies had varying grades of malnutrition and only 1 (7%) of preterm-LBW subset and 13 (28%) of term-LBW subset had optimum catch up growth resulting in normal nutritional status with the existing interventions. Three (3.5%) of the normal babies were noted to slip down to malnutrition at the end of 2 years.

Conclusions: Preterm- and term-LBW babies are born with significantly lower nutrient reserves at birth compared to term-normal babies, this was lowest among the preterm babies. As this reserve may be further lowered by recurrent infections and inappropriate feeding habits, there is a need for special feeding and nutrient supplements in this group. Calcium and iron levels were suboptimum at birth and calcium levels remained suboptimum even at the end of 2 years in all three subsets including controls in this non-affluent group. Currently available interventions may prevent the occurrence of overt clinical nutrient deficiencies, but do not ensure optimum growth, even among normal birth weight babies as some of these babies were seen to slip into the pool of malnutrition subsequently. Specialized nutritional surveillance and supplements are recommended for LBW babies to promote optimum growth and prevent subclinical nutrient deficiencies. Infant feeding practices should be strengthened and integrated with the existing health care programs to reach all the beneficiaries. Along with the existing special supplementation programs like iron folic acid, vitamin A, iodine etc., calcium supplementation should also be considered. It is also essential to concentrate on the girl child, the adolescent girl, prospective mother and prenatal mother to ensure optimum nutrition and nutrient transfer to future offsprings.