The company has identified progesterone metabolites linked to preterm birth and is looking to develop them for predicting risk of delivery prior to 32 weeks.
The notes will be sold at an initial effective conversion price of about $38.79 per share, approximately a 30 percent premium to Monday's $29.84 per share closing price.
The company is withdrawing its previous financial guidance for 2020, saying that it cannot predict the extent or duration of the impact of the COVID-19 pandemic.
Under the 2018 agreement, the companies had planned to develop cell-free DNA assays for prenatal screening using Qiagen's GeneReader sequencing system.
The at-home test is designed to measure the presence of PdG, a urine metabolite of the hormone progesterone, to help women confirm successful ovulation.
The firm reported quarterly revenues of $8.4 million and large increases in the number of billable tests delivered in the quarter and over the full year.
The firm plans to use the cash to support commercial expansion of its NIPT to all US states and fund R&D for future diagnostic tests, including liquid biopsies.
Public Health England will use the company's Victor EnLite instrument and EnLite Neonatal TREC kit at three of six sites to evaluate screening newborns for "Bubble Boy" disease.
The urine-based test, which was already available in several markets, does not require any specialized instrumentation and produces results in less than three minutes.
The company attributed its revenue shortfall to billing issues in the prenatal testing business and announced that CFO Bryan Riggsbee will be interim CEO.
CEO Prahlad Singh said the firm is developing a PCR- and antibody-based assay for the novel coronavirus 2019-nCoV and is working with the Chinese NMPA.
Natera discussed its cancer and transplant rejection testing businesses, while Exact Sciences explained how it will benefit from its Genomic Health acquisition.
