Estimation on risk of spontaneous abortions by genomic disorders from a meta-analysis of microarray results on large case series of pregnancy losses

A meta-analysis on seven large case series (>1000 cases) of chromosome microarray analysis (CMA) on products of conceptions (POC) evaluated the diagnostic yields of genomic disorders and syndromic pathogenic copy number variants (pCNVs) from a collection of 35,130 POC cases. CMA detected chromosomal abnormalities and pCNVs in approximately 50% and 2.5% of cases, respectively. The genomic disorders and syndromic pCNVs accounted for 31% of the detected pCNVs, and their incidences in POC ranged from 1/750 to 1/12,000. The newborn incidences of these genomic disorders and syndromic pCNVs were estimated in a range of 1/4000 to 1/50,000 live births from population genetic studies and diagnostic yields of a large case series of 32,587 pediatric patients. The risk of spontaneous abortion (SAB) for DiGeorge syndrome (DGS), Wolf-Hirschhorn syndrome (WHS), and William-Beuren syndrome (WBS) was 42%, 33%, and 21%, respectively. The estimated overall risk of SAB for major genomic disorders and syndromic pCNVs was approximately 38%, which was significantly lower than the 94% overall risk of SAB for chromosomal abnormalities. Further classification on levels of risk of SAB to high (>75%), intermediate (51%-75%), and low (26%-50%) for known chromosomal abnormalities, genomic disorders, and syndromic pCNVs could provide evidence-based interpretation in prenatal diagnosis and genetic counseling.

Associations between the exposure to organophosphate flame retardants during early pregnancy and the risk of spontaneous abortion based on metabolomics combined with tandem mass spectrometry

BACKGROUND

As potential substitutes for polybrominated diphenyl ethers (PBDEs), organophosphate flame retardants (OPFRs) have been frequently detected in the environment. They have been suggested to impair fetal growth and development in toxicological studies. However, there are few studies on their maternal effects before or during early pregnancy.

METHODS

This study was designed to investigate whether exposure to OPFRs before or during early pregnancy is associated with the risk of spontaneous abortion (SAB), using a nested case-control design based on the case data from clinical examinations in Shanghai, China. A total of 110 cases from this cohort project in 2019-2020 were included. The concentrations of OPFRs in maternal urine samples collected in early pregnancy were determined using Ultra high performance liquid chromatography- triple quadrupole mass spectrometer (UHPLC-MS/MS), and pregnancy outcomes were extracted from the medical records. Meanwhile, ultra high performance liquid chromatography time-of-flight mass spectrometer (UHPLC-Q-TOF/MS)-based metabonomics was used to obtain urine metabolic profiles of 110 women in early pregnancy.

RESULTS

According to the quantitative results, the content of bis(1-chloro-2-propyl)phosphate (BCIPP) in urine was significantly different between the SAB patients and the healthy pregnant women. Besides, metabolic profile analysis showed a significant difference in the urine metabolism profile in early pregnancy between SAB cases and controls. Twenty-five different metabolites were screened out, which showed different degrees of correlation with the urinary BCIPP concentration.

CONCLUSIONS

Based on these results, it suggests that there may be a certain correlation between BCIPP concentration in the urine and the risk of SAB from a metabolomics perspective, and its effect may be related to the metabolism of tryptophan and fatty acids.