Changes of Serum Gonadotropin Levels and Sex Differences in Premature and Mature Infant during Neonatal Life

Abstract

We measured FSH and LH concentrations by RIA in 130 cord sera and 213 peripheral sera obtained as serially as possible from 67 infants who were 5-75 days old and were born between the 28th and 42nd gestational weeks. Cord serum FSH and LH (+hCG) levels were 3.9-13.6 mIU/ml and 43.3-88.6 mIU/ml, respectively; they decreased with advancing gestational age. Postnatal FSH levels in male infants maintained low levels (3.7-8.7 mIU/ml). However, those in female infants increased with peak levels (51.8-270.3 mIU/ml) between 11 and 30 days after delivery, and then decreased; the surge was more marked and prolonged in preterm infants than in term infants. Postnatal LH levels in both sexes decreased rapidly after birth, which may be due to a decrease of placental hCG, and thereafter displayed patterns similar to FSH levels. We found a significant sex difference of serum gonadotropin levels in newborn infants and differences between term and preterm infants. Our results suggest that the sex difference of pituitary gonadal function exists and that the function matures during the fetal and neonatal life.

Influence of preterm birth and small birth size on serum anti-Müllerian hormone levels in young adult women

“…From the present study, we can conclude that this was unlikely caused by a reduced primordial follicle pool count. An effect of gestational age on FSH and LH levels in infants born preterm has also been reported (25,26), but this had never been studied in adult women. Our study shows that gestational age does neither affect FSH nor LH levels in young women.…”

Preterm ovarian hyperstimulation syndrome presented with vaginal bleeding: a case report

“…Fetal gonadotropins decrease during the last trimester of pregnancy, but increase after birth. This transient increase of gonadotropin levels after birth is known as the mini-puberty (12). FSH and LH levels in the newborn peak at 3 to 4 months of age and then subsequently decrease, reaching prepubertal levels at 2-3 years of age (13,14).…”

“…In the present case, we did not observe any high E 2 concentration-dependent accelerated growth and bone maturation. This condition has been explained by decreased peripheral E 2 receptor sensitivity that is a result of immature gonadal axis (12,17). In contrast to this hypothesis, the initial signs were the breast enlargement (Tanner II) and vaginal bleeding in addition to swellings in our case.…”

Changes of Pituitary Gland Volume in Kennedy Disease

“…An increase of LH and FSH at puberty, for example, leads to further enlargement. 22,23 Volume also increases steadily with age in healthy subjects, in women up to a peak in the second decade and in men in the third decade. 24 It could also be shown that high concentrations of gonadotropic hormones induced by the age-related drop in circulating gonadal steroids in climacteric women correlated with an increase of pituitary height.…”