Endometrial microbiota composition is associated with reproductive outcome in infertile patients.

Background: Previous evidence indicates associations between the female reproductive tract microbiome composition and reproductive outcome in infertile patients undergoing assisted reproduction. We aimed to determine whether the endometrial microbiota composition is associated with reproductive outcomes of live birth, biochemical pregnancy, clinical miscarriage or no pregnancy.

Methods: Here, we present a multicentre prospective observational study using 16S rRNA gene sequencing to analyse endometrial fluid and biopsy samples before embryo transfer in a cohort of 342 infertile patients asymptomatic for infection undergoing assisted reproductive treatments.

Natural cycle IVF reduces the risk of low birthweight infants compared with conventional stimulated IVF.

Study Question: Are perinatal outcomes improved in singleton pregnancies resulting from fresh embryo transfers performed following unstimulated/natural cycle IVF (NCIVF) compared with stimulated IVF?

Summary Answer: Infants conceived by unstimulated/NCIVF have a lower risk of being low birthweight than infants conceived by stimulated IVF; however, this risk did not remain significant after adjusting for gestation age.

What Is Already Known: Previous studies have shown that infants born after modified NCIVF have a higher average birthweight and are less likely to be low birthweight than those infants conceived with conventional stimulated IVF.

Study Design, Size And Duration: Retrospective cohort study of singleton live births in non-smoking women undergoing fresh IVF-embryo transfer cycles from 2007 to 2013 in a single IVF center.

Follicular and estradiol parameters that improve success with natural cycle in vitro fertilization.

Objective: To describe clinical thresholds for follicle size and estradiol levels to optimize success with natural cycle in vitro fertilization (NCIVF).

Study Design: Descriptive cohort of candidates for stimulated IVF, < 43 years old, with regular menstrual cycles, regardless of ovarian reserve or fertility treatment history. Patients underwent NCIVF, defined as oocyte retrieval, fertilization and embryo transfer after human chorionic gonadotropin (hCG) trigger without luteinizing hormone (LH) suppression or ovarian stimulation medications.

Utilization and success rates of unstimulated in vitro fertilization in the United States: an analysis of the Society for Assisted Reproductive Technology database.

Objective: To examine the utilization and outcomes of natural cycle (unstimulated) IVF as reported to the Society of Assisted Reproductive Technology (SART) in 2006 and 2007.

Design: Retrospective analysis.

Setting: Dataset analysis from the SART Clinical Outcome Reporting System national database.