tailieunhanh - Polycystic Ovary Syndrome - part 7

Vì vậy, trong các quần thể nhất định của con người, hyperandrogenism bà mẹ trong thai kỳ có thể làm giảm chức năng nhau thai tới một mức độ phát triển của thai nhi bị tổn thương và trọng lượng lúc sinh là giảm. | 92 Abbott et al. to non-PCOS mothers 57 whereas associations between low birthweight and PCOS in larger studies of northern European women have not revealed similar outcomes Finland 58 Netherlands 59 and United Kingdom 60 . Therefore in certain human populations maternal hyperandrogenism in pregnancy might impair placental function to such a degree that fetal development is compromised and birthweight is reduced. Such speculation is consistent with findings that impaired placental aromatization in human pregnancies is accompanied by low birthweight infants 49 61 and may be associated with reduced uteroplacental blood flow 49 . Furthermore in non-primate mammals such as rats experimentally induced maternal hyperandrogenism increases the risk of low birthweight offspring in pregnancies exposed to a variety of stressors 50 suggesting that hyperandrogensim during pregnancy may increase the risk of placental insufficiency. . Adolescence Juvenile prenatally androgenized female rhesus monkeys display enhanced frequencies of behaviors typically associated with juvenile males regardless of whether they are exposed to androgen excess during early or late gestation 62 or whether they received exogenous testosterone or the non-aromatizable androgen dihydrotestosterone DHT 43 . There is a tendency toward tomboy behavior in pre-adolescent PCOS girls 63 whereas fetal androgen excess induced by classical congenital adrenal hyperplasia also produces tomboy behavior in affected girls 64 65 . Menarche is delayed in prenatally androgenized female monkeys exposed early in gestation to either testosterone or DHT and luteal phase defects are unusually frequent following menarche 66 . Such adolescent menstrual cycle disorders precede oligomenorrhea and amenorrhea in adult prenatally androgenized female monkeys Fig. 3 regardless of gestational timing of androgen excess. Fig. 3. Mean SEM menstrual cycles in six early- and five late-treated prenatally androgenized PA and six control .