Urinary concentration of phthalates and bisphenol A during minipuberty is associated with reproductive hormone concentrations in infant boys.

BACKGROUND: The transient postnatal activation of the hypothalamic-pituitary-gonadal hormone axis is termed minipuberty and considered an important developmental period, which is highly sensitive to endocrine disruption. Here, we explore exposure-outcome associations during minipuberty between concentrations of potentially endocrine disrupting chemicals (EDCs) in urine of infant boys and their serum reproductive hormone concentrations. METHODS: In total, 36 boys participating in the COPENHAGEN Minipuberty Study had data available for both urine biomarkers of target endocrine disrupting chemicals and reproductive hormones in serum from samples collected on the same day. Serum concentrations of reproductive hormones were measured by immunoassays or by LC-MS/MS. Urinary concentrations of metabolites of 39 non-persisting chemicals, including phthalates and phenolic compounds, were measured by LC-MS/MS. Nineteen chemicals had concentrations above the limit of detection in ≥50% of children and were included in data analysis. Associations of urinary phthalate metabolite and phenol concentrations (in tertiles) with hormone outcomes (age- and sex-specific SD-scores) were analysed by linear regression. Primarily, we focused on the EU regulated phthalates; butylbenzyl phthalate (BBzP), di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and di-(2-ethylhexyl) phthalate (DEHP) as well as bisphenol A (BPA). Urinary metabolites of DiBP, DnBP and DEHP were summed and expressed as ∑DiBPm, ∑DnBPm and ∑DEHPm. RESULTS: Compared to boys in the lowest ∑DnBPm tertile, urinary concentration of ∑DnBPm was associated with concurrent higher luteinizing hormone (LH) and anti-Müllerian hormone (AMH) SD-scores as well as lower testosterone/LH ratio in boys in the middle ∑DnBPm tertile (estimates (CI 95%) 0.79 (0.04; 1.54), 0.91 (0.13; 1.68), and -0.88 (-1.58;-0.19), respectively). Further, higher insulin-like peptide 3 (INSL3) SD-scores and lower DHEAS SD-score in boys in the highest ∑DnBPm tertile (0.91 (0.12; 1.70) and -0.85 (-1.51;-0.18), respectively) were observed. In addition, boys in the middle and highest ∑DEHPm tertile had higher LH (1.07 (0.35; 1.79) and 0.71 (-0.01; 1.43), respectively) and in the highest ∑DEHPm tertile also higher AMH (0.85 (0.10; 1.61)) concentration SD-scores, respectively. Boys in the highest BPA tertile had significantly higher AMH and lower DHEAS concentration compared to boys in the lowest BPA tertile (1.28 (0.54; 2.02) and -0.73 (-1.45; -0.01)), respectively. DISCUSSION: Our findings indicate that exposure to chemicals with known or suspected endocrine disrupting potential, especially the EU-regulated DnBP, DEHP and BPA, may modify male reproductive hormone concentrations in infant boys suggesting that minipuberty is a critical window sensitive to endocrine disruption.

A Biphasic Pattern of Reproductive Hormones in Healthy Female Infants: The COPENHAGEN Minipuberty Study.

CONTEXT: Minipuberty, a period of a transient activation of the hypothalamic-pituitary-gonadal (HPG) axis in both sexes, enables evaluation of gonadal function in infants suspected of hypogonadism. However, female minipuberty remains poorly elucidated. OBJECTIVE: We aimed to establish continuous reference ranges for the most commonly used reproductive hormones and to evaluate the dynamics of the HPG axis in females aged 0 to 1 year. DESIGN: The COPENHAGEN Minipuberty Study (ClinicalTrials.gov ID: NCT02784184), a longitudinal, prospective cohort study. SETTING: Healthy infants from Copenhagen. PATIENTS OR OTHER PARTICIPANTS: A total of 98 healthy, term female infants followed with 6 examinations including venipuncture during the first year of life. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Serum concentrations of LH, FSH, inhibin B, anti-Müllerian hormone (AMH), estrone (E1), estradiol (E2), and SHBG were quantified using highly sensitive methods in 266 serum samples. RESULTS: Reference ranges were established for LH, FSH, inhibin B, AMH, E1, E2, and SHBG. Two peaks were observed in normalized mean curves for all hormones. The first peaks were timed around postnatal days 15 to 27 followed by a general nadir for all hormones around days 58 to 92. The second peaks occurred around days 107 to 125 for inhibin B, AMH, E1, E2, and SHBG and days 164 to 165 for LH and FSH. CONCLUSIONS: We present age-related, continuous reference ranges of the most commonly used reproductive hormones and present novel data revealing a biphasic and prolonged female minipuberty. CLINICALTRIALS.GOV ID: NCT02784184.

Predictors of emergency cesarean section in women with preexisting diabetes.

OBJECTIVE: Preexisting diabetes in pregnancy is associated with a high risk of emergency cesarean section (CS), which is associated with increased risk of maternal and neonatal complications. Thus, the aim of this study was to identify possible predictors of emergency CS in women with preexisting diabetes. STUDY DESIGN: This is a secondary analysis of a prospective observational study of 204 women with preexisting diabetes (118 with type 1 diabetes and 86 with type 2) with singleton pregnancies recruited at Rigshospitalet, Copenhagen, Denmark from August 2015 to February 2018. Mode of delivery (trial of labor or planned CS) was individually planned in late pregnancy based on clinical variables reflecting maternal and fetal health including glycemic control and ultrasonically estimated fetal weight. Univariate and multivariable analyses were performed to identify possible predictors of in labor emergency CS. RESULTS: Trial of labor was planned in 79 % (n = 162) of the women of whom 65 % (n = 105) were delivered vaginally and 35 % (n = 57) by an emergency CS, while the remaining 21 % (n = 42) were offered a planned CS. Nulliparity (adjusted odds ratio (aOR) 5.6 95 % CI 1.7-18.8), presence of a hypertensive disorder (aOR 2.8, 95 % CI 1.2-6.7) and previous CS (aOR 6.7, 95 % CI 1.5-28.9) were independently associated with an emergency CS. Maternal height was inversely associated with emergency CS (aOR 0.6 95 %, CI 0.5-0.9 per 5 cm decrease). Neither maternal HbA1c nor ultrasonically estimated fetal size in late pregnancy were associated with emergency CS. Women scheduled for a planned CS were characterized by poorer glycemic control and higher estimated fetal size than those offered a trial of labor. CONCLUSION: Nulliparity, presence of a hypertensive disorder, previous CS and shorter maternal height were predictors of emergency CS in women with a planned trial of labor, whereas this not was the case for late pregnancy maternal Hba1c or fetal size estimated by ultrasound.