Circulating AMH reflects ovarian morphology by magnetic resonance imaging and 3D ultrasound in 121 healthy girls.

CONTEXT: In adult women, Anti-Müllerian hormone (AMH) is produced by small growing follicles, and circulating levels of AMH reflect the number of antral follicles as well as primordial follicles. Whether AMH reflects follicle numbers in healthy girls remains to be elucidated. OBJECTIVE: This study aimed to evaluate whether serum levels of AMH reflects ovarian morphology in healthy girls. DESIGN AND SETTING: This was a population-based cohort study involving the general community. PARTICIPANTS: Included in the study were 121 healthy girls 9.8-14.7 years of age. MAIN OUTCOME MEASURES: Clinical examination, including pubertal breast stage (Tanner's classification B1-5), ovarian volume, as well as the number and size of antral follicles were assessed by two independent modalities: magnetic resonance imaging (MRI), Ellipsoid volume, follicles ≥2 mm; and Transabdominal ultrasound, Ellipsoid and 3D volume, follicles ≥1 mm. Circulating levels of AMH, inhibin B, estradiol, FSH, and LH were assessed by immunoassays; T and androstenedione were assessed by liquid chromatography-tandem mass spectrometry. RESULTS: AMH reflected the number of small (MRI 2-3 mm) and medium (4-6 mm) follicles (Pearson's Rho [r] = 0.531 and r = 0.512, P < .001) but not large follicles (≥7 mm) (r = 0.109, P = .323). In multiple regression analysis, small and medium follicles (MRI ≤ 6 mm) remained the main contributors to circulating AMH (ß, 0.501; P < .001) whereas the correlation between AMH and estradiol was negative (ß, -0.318; P = .005). In early puberty (B1-B3), the number of AMH-producing follicles (2-6 mm) correlated positively with pubertal stages (r = 0.453, P = .001), whereas AMH levels were unaffected (-0.183, P = .118). CONCLUSIONS: Similarly to adult women, small and medium antral follicles (≤6 mm) were the main contributors to circulating levels of AMH in girls.

Pubertal onset in girls is strongly influenced by genetic variation affecting FSH action.

Age at pubertal onset varies substantially in healthy girls. Although genetic factors are responsible for more than half of the phenotypic variation, only a small part has been attributed to specific genetic polymorphisms identified so far. Follicle-stimulating hormone (FSH) stimulates ovarian follicle maturation and estradiol synthesis which is responsible for breast development. We assessed the effect of three polymorphisms influencing FSH action on age at breast deveopment in a population-based cohort of 964 healthy girls. Girls homozygous for FSHR -29AA (reduced FSH receptor expression) entered puberty 7.4 (2.5-12.4) months later than carriers of the common variants FSHR -29GG+GA, p = 0.003. To our knowledge, this is the strongest genetic effect on age at pubertal onset in girls published to date.

Association of placenta organotin concentrations with growth and ponderal index in 110 newborn boys from Finland during the first 18 months of life: a cohort study.

BACKGROUND: Humans are exposed to tributyltin (TBT), previously used as an antifouling paint in ships, mainly through fish consumption. As TBT is a known obesogen, we studied the association of placenta TBT and other organotin compounds (OTCs) with ponderal index (PI) and growth during the first 18 months of life in boys. METHODS: In a prospective Finnish study, 110 placenta samples were collected from mothers of boys born in 1997-1999 with (n = 55) and without (n = 55) cryptorchidism. To account for the original study design, linear regression, weighted for sampling fractions of boys with (121/55) and without (5677/55) cryptorchidism from the total cohort, was used to study the association between placenta OTCs and children's weight, length, growth rates and PI up to 18 months of age. RESULTS: Placenta TBT concentrations were above the limit of quantification (LOQ) in 99% of the samples. However, monobutyltin (MBT), dibutyltin (DBT) and triphenyltin (TPhT) concentrations were below LOQ in 90%, 35% and 57% of samples, respectively. Placenta TBT was positively associated (p = 0.024) with weight gain during the first three months of life, but no other significant associations were observed for weight or length gain. Also, no significant associations between placenta OTC concentrations and child length, weight or PI at any time point were found. CONCLUSIONS: We observed a trend towards higher weight gain from birth to 3 months of age with increasing placenta TBT concentration. These results should be interpreted with caution because obesogenic effects in animal experiments were seen after in-utero TBT exposures to doses that were orders of magnitude higher. Also the number of study subjects included in this study was limited.

Association of placenta organotin concentrations with congenital cryptorchidism and reproductive hormone levels in 280 newborn boys from Denmark and Finland.

STUDY QUESTION: Is the placental burden of organotin compounds (OTCs) associated with congenital cryptorchidism in infant offspring from Finland and Denmark? SUMMARY ANSWER: Increasing concentrations of OTCs had a negative association with cryptorchidism in Finland, whereas a positive association was found in Denmark. WHAT IS KNOWN ALREADY: The rapid increase in the prevalence of cryptorchidism suggests that environmental factors, such as endocrine disruptors, may be involved. OTCs are endocrine disruptors at very low concentrations due to activation of the retinoid X receptor (RXR). STUDY DESIGN, SIZE, DURATION: Between the years 1997 and 2001, placentas from mothers of cryptorchid boys and from healthy controls were collected from Denmark (39 cases, 129 controls) and Finland (56 cases, 56 controls). In Denmark 33 and 6 boys, and in Finland 22 and 34 boys had mild or severe cryptorchidism, respectively. The association between concentrations of four OTCs [monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT) and triphenyltin (TPhT)] and case-control status was estimated. PARTICIPANTS/MATERIALS, SETTING, METHODS: In both countries, placenta samples were selected from larger cohorts. In Finland placenta samples were collected from boys with cryptorchidism at birth and matched controls (nested case-control design). Matching criteria were parity, maternal smoking (yes/no), diabetes (yes/no), gestational age (±7 days) and date of birth (±14 days). Numbers of controls per case was 1. In Denmark, all available placentas from cryptorchid boys were chosen and control placentas were selected randomly from the total Danish cohort (case-cohort design). The average number of controls per case was 3.3. OTCs in placenta samples were analysed with liquid extraction, ethylation and gas chromatography-mass spectrometry determination and coded by country-specific tertiles. MAIN RESULTS AND THE ROLE OF CHANCE: Generally, the concentrations of OTCs were very low. For most analytes, a large proportion of samples (29-96% depending on the country and case-control status) had OTC concentrations below the limit of quantification (LOQ). As an exception, the concentration of TBT was >LOQ in 99% of Finnish placentas. The mean concentrations of DBT and TBT were 1.5 and 7 times higher in Finland than in Denmark, respectively. For DBT in Danish placentas, the odds ratio (OR) for cryptorchidism in the second tertile (0.10-0.14 ng/g) when compared with the first tertile (<0.10 ng/g,