Weighing costs of fertility treatments; cheaper can mean more babies.(Knight Ridder Newspapers)

WICHITA, Kan. _ Sondra Headrick is in the 27th week of a pregnancy perilous for herself and the six babies growing inside her.

Her sextuplets resulted from the use of powerful drugs that stimulate the ovaries _ the only fertility treatment Sondra and her husband, Eldon, could afford.

Doctors say the dangerous though rare outcome could have been avoided if the Headricks had had access to a more costly infertility treatment called in vitro fertilization, or IVF.

IVF allows doctors more control over how many babies a woman ends up carrying. But it costs about $8,000 a cycle, compared with $1,000 to $1,500 a cycle for fertility drugs.

And few health insurance plans cover IVF. Kansas is among 36 states that do not require insurers to offer some fertility coverage.

It's an issue more couples will face as a growing number seek treatment for infertility.

"The decisions we have to make are not driven by ends-based medicine," said David Grainger, a Wichita fertility specialist who treated the Headricks. "They're driven by the economics of what the patient can afford."

But insurance companies counter that they can't cover everything.

"Insurance started out as …