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Biomedical subjects

J F McKiernan

Publications and source records attributed to J F McKiernan.

4 recordsLinked to original sources
PubMed1981

Is sebaceous gland hypertrophy in the newborn androgen induced?

Sebaceous gland hypertrophy is almost always present on the face of newborn infants and yet its aetiology is obscure. Androgens, either maternal or fetal, are thought to be related to its development. In a study of the extent and distribution of sebaceous gland hypertrophy in 115 newborn infants, it was found that there was no difference between males and females, and that the condition was more extensive in preterm infants. As circulating testosterone levels are higher in male newborns, and as maternal androgen excretion increases as pregnancy progresses, it is concluded that the appearance of sebaceous gland hypertrophy at birth is independent of androgens and may well be a developmental stage in the maturation of the skin.

Androgens↗
PubMed1981

Prolactin, maternal oestrogens, and breast development in the newborn.

To investigate the influence of maternal oestrogens on the fetal breast development, maternal urinary oestriol excretion, maternal plasma oestriol concentrations, and cord venous plasma oestradiol and oestriol concentrations were related to the size of the neonatal breast. A significant positive association between oestriol excretion and neonatal breast size was demonstrated, but the relationship was not strong and might be due to both measures having a positive relationship with birthweight. The infants' circulating concentrations of prolactin at birth and during the first weeks of life were also related to breast size. There was no cord venous-arterial difference in prolactin concentrations, and neither related to breast diameter. However there was a strong association between breast size and prolactin concentrations in mature infants aged between 5 and 7 days. In preterm infants breast tissue often develops after birth. Prolactin levels in preterm infants were higher between 2 and 6 weeks than they were in the first week of life. It would appear that the early development of the breast is influenced more by the infants's than the mother's endocrine activity.

Anthropometry↗
PubMed1981

Breast development in the newborn.

Breast size and milk secretion was studied in term and preterm infants. Breast nodules were palpable in most of the mature infants, both boys and girls. In 6 term infants without palpable breast tissue there was a high incidence of complications during late pregnancy or delivery. In light-for-gestational age infants the breast diameter was generally appropriate for gestation. None of the infants under 31 weeks' gestation had palpable breast tissue at birth, but some in the first weeks of life developed breast tissue and secreted milk. Milk had been secreted by most of the mature infants by age 7 days, and the onset was earlier in light-for-dates infants. The breast does not regress rapidly after birth. The nodules persist into the second half of the first year by which time sex differences have emerged. Clearly the growth and activity of the neonatal breast cannot be explained solely in terms of the influence of maternal hormones towards the end of gestation. Further studies on early breast tissue development may indicate the other endocrine factors concerned.

Anthropometry↗