Shares of Aspect Medical Systems ( ASPM) were among the worst-performing health-related stocks Wednesday, slumping 13% after the medical-device maker posted better-than-expected fourth-quarter results but issued a first-quarter earnings guidance that fell below Wall Street's forecast.

The company's fourth-quarter earnings rose to $3.1 million, or 13 cents a share, from $955,000, or 5 cents a share, a year earlier. Sales grew to $21.6 million from $15.7 million. Analysts polled by Thomson First Call expected earnings of 11 cents a share and sales of $20.7 million.

Looking ahead, Aspect Medical sees first-quarter earnings of 3 cents to 4 cents a share, or 11 cents to 12 cents a share excluding stock-based compensation costs. The company predicts sales of $21.5 million to $22.2 million. Analysts project earnings of 13 cents a share on sales of $21.8 million. Aspect Medical said that product launch and sales force expenses would have a modest impact on earnings during the first quarter. Shares were trading down $4.54 to $31.42.

Cyberonics ( CYBX) fell 2% after the medical-device maker turned in third-quarter results that were well below expectations. For the quarter ended Jan. 27, the company posted a loss of $14.6 million, or 58 cents a share, on sales of $31.3 million. Analysts expected a smaller loss of 35 cents a share, with sales of $36.9 million. During the year-earlier quarter, the company had a loss of about $817,000, or 3 cents a share, on sales of $26.2 million.

For the fourth quarter, Cyberonics forecast sales of $34 million, well below the $44.5 million that analysts had been projecting. Shares recently were trading down 60 cents to $27.63, after reaching a 52-week low of $24.55 earlier in the day.

Shares of Pediatrix Medical Group ( PDX) rose 8% after the contract medical services provider posted fourth-quarter earnings that topped expectations. The company reported earnings of $15.9 million, or 65 cents a share, on sales of $177.7 million. Excluding items, the company earned $31.6 million, or $1.30 a share. Analysts expected earnings of $1.28 a share and sales of $181.3 million. During the year-earlier period, the company earned $25.8 million, or $1.10 a share, on sales of $161 million.

Looking ahead, Pediatrix Medical sees first-quarter earnings of 95 cents to 97 cents a share, or $1.08 to $1.10 a share excluding stock-based compensation costs. Analysts project earnings of $1.13 a share. For the second quarter, the company sees earnings of $1.22 to $1.24 a share, or $1.36 to $1.38 a share excluding stock-based compensation expenses. Analysts project earnings of $1.36 a share. For all of 2006, the company expects earnings of $4.83 to $4.93 a share, or $5.42 to $5.52 a share excluding stock-based compensation costs. Analysts project earnings of $5.40 a share. Shares were trading up $7.08 to $92.34.

Apria Healthcare ( AHG) shares rose modestly after the company posted mixed fourth-quarter results. The home health care company earned $19.5 million, or 43 cents a share, on sales of $359.7 million. Excluding items, the company earned $18 million, or 40 cents a share. Analysts expected lower earnings of 38 cents a share, but also forecast higher sales of $376.8 million. During the year-ago quarter, the company earned $27.3 million, or 55 cents a share, on sales of $376.4 million.

For 2006, Apria expects earnings of $1.78 to $1.82 a share, with sales growth of 4% to 5%. Analysts project earnings of $1.82 a share and sales of $1.55 billion, or sales growth of about 5%. Shares were trading up 23 cents to $23.99.

Shares of EpiCept ( EPCT) slumped 12% after the pharmaceutical company agreed to sell about 4.1 million shares of stock for $2.85 apiece in a private placement, resulting in gross proceeds of $11.6 million. The sale price represents a 27% discount to EpiCept's closing price of $3.90 a share on Tuesday. The company also issued five-year warrants to buy up to 1 million shares of stock at an exercise price of $4 a share. Shares were down 47 cents to $3.43.

Other health care volume movers included Pfizer ( PFE), up $1.26 to $26.20; Boston Scientific ( BSX), down 7 cents to $22.19; Johnson & Johnson ( JNJ), up $1.32 to $58.12; Genta ( GNTA), down 8 cents to $3.28; Amgen ( AMGN), down $1.03 to $71.91; Bristol-Myers Squibb ( BMY), up 16 cents to $22.62; Schering-Plough ( SGP), up 15 cents to $18.60; Elan ( ELN), down 19 cents to $14.45; and Merck ( MRK), up 51 cents to $34.20.