Neonatal Hair as a Record of Intra-Uterine Nutrition

Abstract

Scalp hair samples were studied from 10 term infants of normal weight for dates, 10 infants born very early of normal weight for dates and 10 infants born near term who were small-for-dates. The samples were examined morphologically and the diameters measured precisely using a scanning electron microscope. The control term-normal weight for dates infants had hairs which tapered gradually to the tip. Infants born very early had narrower hairs: these could be superimposed on the distal segments of the term infants hairs. Small-for-dates infants had hairs which where shorter and of narrower diameter for gestational age than the equivalent hair segments from normally grown infants, implying growth constraint from about 20 weeks of gestation. Amino acid analysis of the hairs from the three groups of infants showed no differences in concentration. These data suggest that no specific disturbance of any one or any groups of amino acids is the growth-limiting factor on the fetus as a whole in intra-uterine growth retardation.

Nutrition, sex, gestational age, and hair growth in babies.

“…Plasma testosterone does not increase with gestational age nor is there a decrease in its plasma protein binding (Reyes et al, 1973), but the maturing hair follicle may be more able to convert testosterone to Soxdihydrotestosterone as fetal enzyme systems mature. The increase in hair root diameter with gestational age is similar to the changes in hair shaft diameter found by Baum et al (1974).…”

“…Similar changes are seen in postnatal malnutrition (Bradfield et al, 1968) and a thinner shaft diameter has been described by Baum et al (1974) in malnourished newborns. The effect of intrauterine malnutrition on the number of growing roots was unexpected.…”

Human Epidermal Embryogenesis

“…76 It is estimated that fetal hair grows at a rate of 2 mm per week , although this can be decreased substantially if there is malnutrition of the fetus. 99 Dermal-epidermal ridges. In the beginning of the fifth month, the entire finger pad ha.s developed a pattern of primary dermal ridges.…”

Successful pregnancy in acute monocytic leukaemia

“…Neonatal hair studied under the scanning microscope was normal and showed no evidence of any cytotoxic damage as was observed in the mother's hair. Since the foetus first develops hair around 20 weeks of gestation (Baum, Hughes and Harris, 1974), this observation suggests that the foetus had not been exposed to significant doses of cytotoxic drugs in the last 17 weeks of pregnancy. However, we know of no evidence as to the minimum cytotoxic dose necessary to produce visible evidence of damage to human hair squames.…”