Association of age at menarche and different causes of infertility: a retrospective study of 7634 women undergoing assisted reproductive technology.

Background: Infertility has become a world-wide public health problem. To identify women in a high-risk of infertility at an early stage when more treatments are available, early risk factors such as age at menarche (AAM) are being investigated. AAM is often used in epidemiological studies as a marker of the timing of pubertal development and the onset of the hypothalamic-pituitary-ovarian axis functions.

Metabolic profiles of children aged 2-5 years born after frozen and fresh embryo transfer: A Chinese cohort study.

Background: Frozen embryo transfer (FET) has become a widely employed assisted reproductive technology technique. There have historically been concerns regarding the long-term metabolic safety of FET technology in offspring due to pregnancy-induced hypertension and large for gestational age, both of which are well-recognized factors for metabolic dysfunction of children. Therefore, we aimed to compare the metabolic profiles of children born after frozen versus fresh embryo transfer at 2 to 5 years of age.