ESPE Abstracts

The transient activation of the hypothalamus-pituitary-gonadal (HPG) axis shortly after birth has been described as early as in the 70ies. This discovery has since been applied clinically as a ‘window of opportunity’ for diagnostic evaluation of patients suspected of endocrine disorders and differences of sex development. With the advent of increasingly more sensitive and specific analytical methods for peptide and steroid hormones produced in the pituitary, gonads, and adrenals our insight into the regulation of this developmental window has improved considerably. Several research groups have investigated the physiology of this so-called ‘mini-puberty’ in boys and girls and described its significance for genital growth and functional development. Some of these effects are easily assessed by clinical examination, ultrasound, and blood samples. Recently, our group has been able to perform a long-term follow-up of a mother-child cohort to show that the HPG axis in infancy also is associated with pubertal development and adult reproductive health. This finding of a reproductive trajectory may not only be important for future clinical care of patients but also for research into adverse influences on reproductive health of future generations. Over the past two decades several groups have shown that in utero and early life exposures to risk factors such as endocrine-disrupting chemicals may have considerable adverse effects on reproductive health. The ability to gain insight into such effects already in infancy is a big advantage considering the long generation time of humans and the urgent need to suggest preventive measures. Thus, pediatric endocrinologists together with scientists from other disciplines can play an important role in unravelling causes for the world-wide increase in infertility and need of fertility treatment which has major societal and personal consequences.