Developing a Prospective Gestational Lyme Disease Study.

Lyme disease in pregnancy is understudied. The few available reports of Borrelia infection during pregnancy collecting clinical outcomes, with or without confirmed fetal infection both in utero and neonatal, are limited to case reports and small series. Population-based studies are not available.

Genome-wide cell-free DNA screening: a focus on copy-number variants.

Purpose: Of 86,902 prenatal genome-wide cell-free DNA (cfDNA) screening tests, 4,121 were positive for a chromosome abnormality. This study examines 490 cases screen-positive for one or more subchromosomal copy-number variants (CNV) from genome-wide cfDNA screening.

Methods: Cases positive for one or more subchromosomal CNV from genome-wide cfDNA screening and diagnostic outcomes were compiled.

Application of mosaicism ratio to multifetal gestations.

Mosaicism ratio, or MR, is a laboratory metric that can be calculated using massively parallel sequencing data from cell-free DNA (cfDNA) screening. MR compares the amount of cfDNA present from a particular chromosome or chromosomal region to the overall fetal fraction of the specimen. In singleton gestations, MR may be used to refine the positive predictive value of an abnormal cfDNA screening result by identifying cases that could be impacted by various biological factors, such as placental mosaicism or prior co-twin demise.

Impact of mosaicism ratio on positive predictive value of cfDNA screening.

Objective: To examine the relationship between the fraction of cell-free DNA (cfDNA) affected by aneuploidy compared to the overall fetal fraction of a prenatal screening specimen and its effect on positive predictive value (PPV).

Method: CfDNA specimens positive for trisomy 13, 18, and 21 with diagnostic outcomes were analysed over a 22-month period in one clinical laboratory. For each positive specimen, a "mosaicism ratio" (MR) was calculated by dividing the fraction of cfDNA affected by aneuploidy by the overall fetal fraction of the specimen.

Analysis of 3208 cystic fibrosis prenatal diagnoses: impact of carrier screening guidelines on distribution of indications for CFTR mutation and IVS-8 poly(T) analyses.

Purpose: To evaluate and quantify indications for CFTR mutation analysis of prenatal specimens, and to determine if a significant portion of tests are performed only for the identification of 5T alleles, we surveyed our laboratory data over a 3-year time period that spanned the issuance of the cystic fibrosis (CF) carrier screening guidelines.

Methods: Referral indications for 3208 prenatal specimens were compared for an 18-month period before (April 2000 to September 2001) and after (October 2001 to April 2003) publication of the ACMG/ACOG statement regarding prenatal and preconception testing for CF.

Results: The frequency of cases received for testing when one or both parents were CF mutation carriers did not change significantly after publication of the guidelines.

Procedural risks versus theology: chorionic villus sampling for Orthodox Jews at less than 8 weeks' gestation.

Objective: According to Orthodox Jewish law, abortion is only permitted before 40 days post conception. This evaluation was performed to determine the feasibility and safety of performing chorionic villus sampling (CVS) at 7 to 8 weeks' gestation so that genetic results would be useful for these patients.

Study Design: We evaluated a sequential series of 82 Orthodox Jewish patients who chose CVS at <63 days' gestation.