Purpose

Modification of the trigger used to induce final oocyte maturation in in vitro fertilization (IVF) is a major strategy used to reduce the risk of ovarian hyperstimulation syndrome (OHSS). A novel trigger composed of 1500 IU of human chorionic gonadotropin (hCG) plus 450 IU of follicle-stimulating hormone (FSH) has been developed to reduce OHSS risk. This study compares outcomes of the novel trigger to conventional triggers used in high-risk OHSS patients undergoing IVF.

Methods

In this retrospective cohort study, IVF cycles at high risk for OHSS based on a serum estradiol > 5000 pg/ml on trigger day conducted between January 2008 and February 2016 were evaluated. Oocyte maturation was induced with the novel trigger (1500 IU hCG plus 450 IU FSH) or a conventional trigger [3300 IU hCG, gonadotropin-releasing hormone agonist (GnRHa) alone, or GnRHa plus 1500 IU hCG]. IVF cycle outcomes were compared. Trigger strategies were examined for associations with OHSS development using logistic regression.

Results

Among 298 eligible IVF cycles identified, there were no differences in oocyte maturation, fertilization, embryo quality, or pregnancy outcomes among all triggers. After adjusting for serum estradiol level and number of follicles, the novel trigger was associated with lower odds of OHSS symptom development compared to the 3300 IU hCG and GnRHa plus hCG 1500 IU triggers (p = 0.007 and 0.04, respectively).

Conclusions

This study suggests that 1500 IU hCG plus 450 IU FSH may be associated with decreased OHSS symptoms compared to conventional triggers, while producing similar IVF and pregnancy outcomes. More important, this novel trigger may provide a superior alternative in down-regulated cycles and in patients with hypothalamic dysfunction where GnRHa triggers cannot be utilized.

The original version of this article unfortunately contained a mistake. The middle initial of Douglas A. Mata was omitted. The original article has been corrected.

Background

Schwannomas are common peripheral nerve sheath tumors that can cause severe morbidity given their stereotypic intracranial and paraspinal locations. Similar to many solid tumors, schwannomas and other nerve sheath tumors are primarily thought to arise due to aberrant hyperactivation of the RAS growth factor signaling pathway. Here, we sought to further define the molecular pathogenesis of schwannomas.

Methods

We performed comprehensive genomic profiling on a cohort of 96 human schwannomas, as well as DNA methylation profiling on a subset. Functional studies including RNA sequencing, chromatin immunoprecipitation-DNA sequencing, electrophoretic mobility shift assay, and luciferase reporter assays were performed in a fetal glial cell model following transduction with wildtype and tumor-derived mutant isoforms of SOX10.

Results

We identified that nearly one-third of sporadic schwannomas lack alterations in known nerve sheath tumor genes and instead harbor novel recurrent in-frame insertion/deletion mutations in SOX10, which encodes a transcription factor responsible for controlling Schwann cell differentiation and myelination. SOX10 indel mutations were highly enriched in schwannomas arising from nonvestibular cranial nerves (eg facial, trigeminal, vagus) and were absent from vestibular nerve schwannomas driven by NF2 mutation. Functional studies revealed these SOX10 indel mutations have retained DNA binding capacity but impaired transactivation of glial differentiation and myelination gene programs.

Conclusions

We thus speculate that SOX10 indel mutations drive a unique subtype of schwannomas by impeding proper differentiation of immature Schwann cells.