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.

Short-term changes in hormonal profiles after laparoscopic ovarian laser evaporation compared with diagnostic laparoscopy for PCOS.

Study Question: Which reproductive endocrine changes are attributed exclusively to laparoscopic ovarian drilling in polycystic ovarian syndrome (PCOS)?

Summary Answer: Laser evaporation-specific endocrine effects were the prevention of an immediate increase in inhibin B and a sustained decrease in testosterone, androstenedione and anti-Müllarian hormone (AMH).

What Is Known Already: All ovarian drilling procedures result in reproductive endocrine changes. It is not known which of these changes are the result of ovarian drilling and which are related to the surgery per se.

Influence of ovarian manipulation on reproductive endocrinology in polycystic ovarian syndrome and regularly cycling women.

Objective: Little is known about the function of the ovarian neuronal network in humans. In many species, copulation influences endocrinology through this network. As a first step, the possible influence of ovarian mechanical manipulation on pituitary and ovarian hormones was evaluated in polycystic ovarian syndrome (PCOS) and regularly cycling women.

Insulin-induced capillary recruitment is impaired in both lean and obese women with PCOS.

Background: Insulin resistance, i.e. impaired insulin-mediated glucose uptake (IMGU), is a major risk factor for type 2 diabetes in women with polycystic ovary syndrome (PCOS).

Pituitary sensitizing effect of GnRH antagonists: a mechanism explaining LH escape during IVF?

Background: GnRH antagonists have been introduced to induce persistent LH suppression. Many studies show a gradual increase of LH levels after several days of GnRH antagonist administration, the so-called escape or rebound effect. We hypothesize that, under chronic GnRH antagonist administration, a higher pituitary response to GnRH could be an underlying mechanism explaining the escape phenomenon.