Prolactin, maternal oestrogens, and breast development in the newborn

Longitudinal evaluation of breast tissue in healthy infants: Prevalence and relation to reproductive hormones and growth factors

INTRODUCTION

Breast tissue in infancy is a rather undescribed phenomenon. We aimed to describe the prevalence and progression of palpable breast tissue in healthy boys and girls aged 0-1 years and to evaluate clinical markers, individual serum hormone concentrations as well as combined hormone profiles as determinants of the persistence of breast tissue.

METHODS

In total, 233 term infants (119 boys, 114 girls) were included and followed from birth until 1 year of age in The COPENHAGEN Minipuberty Study (ClinicalTrials.gov #NTC02784184). Infants were followed up to six times with a clinical examination and serum sampling. Principal component analyses (PCAs) produced combined hormone profiles.

RESULTS

A total of 98% of all infants aged 0-1 year exhibited breast tissue at some point. 50% still had breast tissue present at 0.5-0.6 years in girls and 0.3-0.4 years in boys ('persistent'). At one year, more girls than boys had breast tissue present (p=0.010). Most clinical and hormonal markers did not differ in infants with/without persistent breast tissue. However, in those with persistent breast tissue, estradiol (first visit, girls, p=0.034), androstenedione, corticosterone, cortisol (first visit, boys, all p<0.050), length (first visit, boys, p=0.030), and testicular volume (0.3-0.4 years, p=0.040) were higher, while IGF-I (0.3-0.4, boys, p=0.033) was lower. In boys, a combined, PCA-derived hormone profile (first visit) was able to predict the persistence of breast tissue (area under the curve=83%) better than any single marker.

DISCUSSION

Palpable breast tissue in infancy is common in both sexes although it persists in significantly more girls than boys at one year of age. Data supports both the early origin of breast tissue (in utero- and early postnatal) as well as a role of endogenous hormone production in later development and maintenance.

Complex Biological Pattern of Fertility Hormones in Children and Adolescents: A Study of Healthy Children from the CALIPER Cohort and Establishment of Pediatric Reference Intervals

BACKGROUND

Pediatric endocrinopathies are commonly diagnosed and monitored by measuring hormones of the hypothalamic-pituitary-gonadal axis. Because growth and development can markedly influence normal circulating concentrations of fertility hormones, accurate reference intervals established on the basis of a healthy, nonhospitalized pediatric population and that reflect age-, gender-, and pubertal stage–specific changes are essential for test result interpretation.

METHODS

Healthy children and adolescents (n = 1234) were recruited from a multiethnic population as part of the CALIPER study. After written informed parental consent was obtained, participants filled out a questionnaire including demographic and pubertal development information (assessed by self-reported Tanner stage) and provided a blood sample. We measured 7 fertility hormones including estradiol, testosterone (second generation), progesterone, sex hormone–binding globulin, prolactin, follicle-stimulating hormone, and luteinizing hormone by use of the Abbott Architect i2000 analyzer. We then used these data to calculate age-, gender-, and Tanner stage–specific reference intervals according to Clinical Laboratory Standards Institute C28-A3 guidelines.

RESULTS

We observed a complex pattern of change in each analyte concentration from the neonatal period to adolescence. Consequently, many age and sex partitions were required to cover the changes in most fertility hormones over this period. An exception to this was prolactin, for which no sex partition and only 3 age partitions were necessary.

CONCLUSIONS

This comprehensive database of pediatric reference intervals for fertility hormones will be of global benefit and should lead to improved diagnosis of pediatric endocrinopathies. The new database will need to be validated in local populations and for other immunoassay platforms as recommended by the Clinical Laboratory Standards Institute.

Bloody nipple discharge in a 7-month-old boy

Isolated bloody nipple discharge is rare in infancy and is usually idiopathic. Discharge commonly resolves spontaneously, and ultrasonography is a useful diagnostic technique to detect the cause of discharge. The authors report a 7-month-old boy who presented with unilateral spontaneous bloody nipple discharge for 1 month without signs of infection or mass.

Establishment of normative data for the amount of breast tissue present in healthy children up to two years of age

OBJECTIVE

To establish a set of normal values for breast size in children up to two years of age, and to assess the effects of gender, gestational age, and type of feeding and growth parameters on breast size.

DESIGN

Prospective cohort study over 20 months

SETTING

The Mayo Clinic Rochester, MN, neonatal nursery and Community Pediatrics Clinic.

PARTICIPANTS

Well term infants and children through two years of age.

INTERVENTIONS

Measurement of breast size based on previously described methods to yield a figure called the breast unit.

MAIN OUTCOME MEASURE

Transformation of breast unit size into percentiles according to age.

RESULTS

The 50(th) to 99(th) percentiles for 810 healthy term Caucasian infant visits were calculated. The 50th breast unit percentile was similar in males and females at birth and declined with age following a quadratic relationship for females and a cubic relationship for males. Breast tissue in female infants remained larger and persisted longer. Palpable breast tissue was still present in 45.2% of male and 61.6% of female visits after 10 months of age. At age 18 months, 5% of girls had a breast size unit greater than 2.88 cm(2) and 5% of boys had a breast size unit greater than 1.00 cm(2).

CONCLUSIONS

These data allow creation of normal standards of breast size for age, which could provide a future clinical tool to assist clinicians in the evaluation of early childhood breast enlargement in similar populations.

Galactorrhea with metoclopramide use in the neonatal unit

We report a 3(1/2)-month-old infant with trisomy 21 presenting with galactorrhea in the neonatal intensive care unit (NICU). Endocrine work-up showed a high prolactin level (64.4 ng ml(-1)--normal: 0.5 to 30 ng ml(-1)). Cessation of therapy with metoclopramide (0.2 mg kg(-1) per dose q 6 h) resulted in the resolution of galactorrhea with a decrease in serum prolactin level (20.1 ng ml(-1)). We present this case to highlight this uncommon side effect of a commonly used medication in the NICU.

Gender difference in breast tissue size in infancy: correlation with serum estradiol

Breast tissue in newborn infants is considered to be physiologic and mainly related to exposure to maternal hormones in utero or through breast-feeding. However, controversy exists as to whether breast tissue in later infancy is under the influence of endogenous hormones. Children at 2-4 mo of age have a surge of reproductive hormones, including estradiol, which may affect the mammary gland. In a prospective cohort study of 1126 healthy, 3-mo-old infants, breast tissue size and reproductive hormones were measured. We found that palpable breast tissue (diameter >or=3 mm) is a common physiologic condition present in 78.9% of children, significantly more frequent (p < 0.001) and larger (p < 0.001) in girls than in boys. Girls had significantly higher median estradiol levels than boys (30.0 versus 21.0 pmol/L, p < 0.001). In a multiple regression model including breast tissue size given as quartiles as the dependent variable and weight for gestational age, subscapular skinfold, weight at 3 mo of age and serum estradiol as independent variables, a gender difference was shown. In girls, the estradiol level was positively (p < 0.03) correlated to breast quartile. In boys, no correlations were found. Whether the stimulation of the mammary gland in infancy represents a developmental window that is of biologic significance for breast development and pathology in adulthood remains to be defined.

Growth of the uterus and mammary glands and vaginal cytologic features in extremely premature infants with postnatal replacement of estradiol and progesterone

OBJECTIVE

Growth of the uterus and the mammary glands and changes in vaginal cytologic features are known to be estrogen dependent and were evaluated to proof the biologic effectiveness of a postnatal replacement of estradiol and progesterone in extremely premature infants.

STUDY DESIGN

Thirty female infants with a mean gestational age of 26.4 weeks (24.1-28.7 weeks) and a mean birth weight of 708 g (370-990 g) were investigated. Fifteen infants received postnatal replacement of estradiol and progesterone for 6 weeks to maintain intrauterine plasma levels of estradiol and progesterone. Uterine size and the diameter of mammary glands were assessed repeatedly by ultrasound scans and palpation. Vaginal smears were also obtained.

RESULTS

The uterus and mammary glands showed significant growth during the hormone replacement, but growth was not observed in nontreated infants. Vaginal smears showed high karyopyknotic and eosinophilic indices in both groups at birth; the indices remained significantly higher at 3 and 6 weeks in the hormone-treated infants.

CONCLUSION

The biologic effectiveness of postnatal estradiol and progesterone replacement in extremely premature infants was proved.

Histology of breast development in early life

Histological examination of the breasts of 26 infants and young children who died suddenly between the ages of 3 weeks and 2 years was performed. The glands were composed of well formed lobules surrounded by dense interlobular stroma, while within the lobules there was looser connective tissue. The lobules contained ducts, many of which were dilated and contained secretions. Foci of extramedullary haematopoiesis were found, and in the older infants, fat was prominent within the connective tissue of the breast. Myoepithelial cells were regularly present. No sex differences in breast development at this time were noted. Newborn breast development did not regress rapidly after birth and secretory activity continued for many months in both sexes. This study shows that the human mammary gland remains active for many months after birth and may continue to grow and secrete. The findings are not consistent with the current view that breast development in infancy results from stimulation from 'pregnancy hormones.' It is more likely that the infant's own gonadal secretions are responsible.

Salt loss in congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency

Nine patients with 11 beta-hydroxylase deficiency had 13 episodes of gastroenteritis requiring hospital admission and fluid administration. Eight episodes were accompanied by hyponatraemia and salt loss. The salt losing patients were treated with excessive glucocorticoid and those with normal serum sodium concentrations were treated with inadequate glucocorticoid. Excessive glucocorticoid suppressed deoxycorticosteroid secretion, resulting in salt loss.

Postnatal breast development of preterm infants. An index of gonadal function

Development of breast nodules after birth was examined in 17 preterm infants; nodules developed regularly in girls but not boys. It is concluded that the pituitary-gonadal axis of preterm infants is active in the months after birth and that in preterm infants there is a definite phase of breast growth in early postnatal life.

Effects of an antenatal load of pyridoxine (vitamin B6) on the blood oxygen affinity and prolactin levels in newborn infants and their mothers

The effects of a loading dose of pyridoxine (100 mg) given intramuscularly or per os to 24 earlier non-supplemented pregnant women at term was investigated. The in vitro oxygen affinity (P50) and the prolactin level in both maternal and newborn blood was sampled. The blood P50 values were measured by a variant of "mixing method". Blood prolactin levels were determined by RIA. After pyridoxine administration, the maternal P50 values increased moderately and the newborns' cord blood P50 values increased significantly when compared with the control group's (number of cases 12) values. The decrease of blood oxygen affinity was most pronounced in the supplemented groups in newborns' capillary blood at the age of five days. The pyridoxine supplementation had no effect on the maternal and the newborns' cord blood prolactin level or on the daily amount of breast milk. Pyridoxine supplementation of the mother at labour may influence favourably the oxygen transport function of the newborn's blood and it may be especially advantageous in early postnatal adaptation disturbances of newborns.