Ariosa pumps the brakes on a planned $68M IPO

A week after setting out to raise as much as $68 million in an IPO, prenatal test outfit Ariosa Diagnostics has removed all financial details from its filing, possibly jeopardizing its plans to go public.

The San Jose, CA, firm had planned to sell 3.5 million shares at between $16 and $18 apiece, according to registration statement filed with the SEC last week, but, in an updated S-1, Ariosa has left those columns blank, saying only that it plans to trade on the Nasdaq under "AROS."

Ariosa didn't disclose a reason for its move, and the company didn't respond to a request for comment Wednesday.

If Ariosa's IPO ambitions pan out, the company plans to spend its raise on expanding the market for Harmony, a prenatal test designed to detect chromosomal abnormalities like Down syndrome and Turner syndrome. Ariosa launched its kit in 2012 and posted $53.3 million in revenue last year, according to the company.

Meanwhile, since Ariosa's initial $68 million pitch, competitor Illumina ($ILMN) has filed a patent lawsuit, seeking an injunction on sales of Harmony. Illumina's Verinata Health segment markets a maternal diagnostic of its own, and the company claims Ariosa infringed its patent on noninvasive DNA screening techniques.

The suit is the latest in a long string of legal actions between rivals in the prenatal testing space, and both Ariosa and Illumina have been in and out of court with competitor Sequenom ($SQNM) over intellectual property disputes. Alongside the privately held Natera, each is scrapping for the largest share of a market analysts say could triple over the next 5 years, potentially reaching $3.6 billion by 2019.

- here's the filing