Mid-pregnancy, perinatal, and neonatal reproductive endocrinology: a prospective cohort study in twins and singleton control subjects.

OBJECTIVE: To answer the questions: Are perinatal reproductive hormone profiles different in case of a twin compared with a singleton pregnancy? Are reproductive endocrine profiles of twin girls influenced by their male co-twin and vice versa? DESIGN: Prospective cohort study from January 2004 to October 2009. SETTING: Not applicable. PATIENT(S): A total of 204 mothers of twins and 248 singleton control subjects, aged >18 years, pregnant with a twin or singleton and no endocrine disease or malignancy. INTERVENTION(S): Blood samples were collected at mid-gestation from the mother and at delivery from the mothers and the umbilical cords. Estrogens, androgens, sex hormone-binding globulin, progesterone, and gonadotropins were measured. MAIN OUTCOME MEASURE(S): Hormonal profiles were compared between singletons and twins, different types of twins, and opposite-sex and same-sex twins. RESULT(S): Estrogen and progesterone concentrations were higher in mothers of twins compared with singletons, but twin babies had lower estrogen and progesterone concentrations at birth. Opposite-sex twin girls did not have higher androgens in cord blood compared with same-sex twin girls. Boys of an opposite-sex twin had lower luteinizing hormone concentrations compared with dizygotic twin boys with a brother as a co-twin. CONCLUSION(S): Children from a twin are not overexposed to sex steroids at the time of birth, despite higher concentrations in their mothers, and girls from opposite sex twins do not show androgenic influences from their male co-twin. The female co-twin may influence the hypothalamic-pituitary-testicular axis of her brother via central inhibition.

Obese but not normal-weight women with polycystic ovary syndrome are characterized by metabolic and microvascular insulin resistance.

CONTEXT: Polycystic ovary syndrome (PCOS) and obesity are associated with diabetes and cardiovascular disease, but it is unclear to what extent PCOS contributes independently of obesity. OBJECTIVE: The objective of the study was to investigate whether insulin sensitivity and insulin's effects on the microcirculation are impaired in normal-weight and obese women with PCOS. DESIGN AND POPULATION: Thirty-five women with PCOS (19 normal weight and 16 obese) and 27 age- and body mass index-matched controls (14 normal weight and 13 obese) were included. Metabolic Insulin sensitivity (isoglycemic-hyperinsulinemic clamp) and microvascular insulin sensitivity [endothelium dependent (acetylcholine [ACh])] and endothelium-independent [sodium nitroprusside (SNP)] vasodilation with laser Doppler flowmetry was assessed at baseline and during hyperinsulinemia. MAIN OUTCOME MEASURES: Metabolic insulin sensitivity (M/I value) and the area under the response curves to ACh and SNP curves were measured to assess microcirculatory function at baseline and during insulin infusion (microvascular insulin sensitivity). RESULTS: Obese women were more insulin resistant than normal-weight women (P < 0.001), and obese PCOS women were more resistant than obese controls (P = 0.02). In contrast, normal-weight women with PCOS had similar insulin sensitivity, compared with normal-weight women without PCOS. Baseline responses to ACh showed no difference in the four groups. ACh responses during insulin infusion were significantly greater in normal-weight PCOS and controls than in obese PCOS and controls. PCOS per se had no significant influence on ACh responses during insulin infusion. During hyperinsulinemia, SNP-dependent vasodilatation did not significantly increase, compared with baseline in the four groups. CONCLUSION: PCOS per se was not associated with impaired metabolic insulin sensitivity in normal-weight women but aggravates impairment of metabolic insulin sensitivity in obese women. In obese but not normal-weight women, microvascular and metabolic insulin sensitivity are decreased, independent of PCOS. Therefore, obese PCOS women in particular may be at increased risk of metabolic and cardiovascular diseases.

Aging women with polycystic ovary syndrome who achieve regular menstrual cycles have a smaller follicle cohort than those who continue to have irregular cycles.

OBJECTIVE: To examine whether follicle loss due to ovarian aging is responsible for the occurrence of regular menstrual cycles in aging women with polycystic ovary syndrome (PCOS), the size of the FSH-sensitive follicle cohort was estimated by the exogenous follicle-stimulating hormone ovarian reserve test (EFORT) and related to the follicle count as measured by ultrasound. DESIGN: Prospective study. SETTING: Reproductive endocrinology unit of an academic medical center. PATIENT(S): Twenty-seven aging women with PCOS (35.8-49.4 years): 20 with regular menstrual cycles and 7 with oligomenorrhea or amenorrhea. INTERVENTION(S): EFORT and transvaginal ultrasound. MAIN OUTCOME MEASURE(S): Baseline (cycle day 2, 3, or 4) FSH, androstenedione (A), T, E(2), and inhibin B levels, the E(2) and inhibin B increment after the EFORT, and the follicle count. RESULT(S): After correction for the body mass index (BMI), the inhibin B increment was higher in the irregular menstrual group, but the E(2) increment did not differ significantly between the two groups. Ultrasound showed a median follicle count of 8.5 (4.0-18.0) in women with regular menstrual cycles (n = 16), compared with 18.0 (8.0-35.0) in irregularly menstruating women (n = 7). The follicle count was significantly correlated to the FSH-induced E(2) increment (r = 0.656) as well as to the inhibin B increment (r = 0.654). The regularly menstruating group was significantly older, had a higher basal FSH concentration, and had lower androgens than the irregularly menstruating group. CONCLUSION(S): The smaller follicle count, the older age, the higher FSH concentration, and the lower FSH-induced inhibin B increment found in women with PCOS and a regular menstrual cycle confirm that a decrease in the size of the follicle cohort due to ovarian aging is largely responsible for the regular menstrual cycles in aging PCOS women.