Leslie Candy of Boston was expecting her first baby when she developed dangerously high blood pressure. The condition, called pre-eclampsia, can cause women to have seizures or strokes if it's not controlled.

Doctors ordered bed rest and gave Candy, 38, intravenous medications to try to lower her blood pressure. There are no effective drugs for pre-eclampsia, however, and her condition worsened after she was hospitalized.

After two days, doctors said the only way to treat the condition was to perform an emergency C-section. They delivered her son in January, seven weeks before his due date. He spent 2 weeks in neonatal intensive care. Candy says she wishes doctors were working on a cure for pre-eclampsia.

Although 4 million American women give birth each year, almost no one is developing medications for complications of pregnancy, including conditions that threaten the lives of mothers and children, says Nicholas Fisk, an obstetrician-gynecologist and director of the University of Queensland Centre for Clinical Research in Australia.

There are so few effective drugs for pregnancy-related conditions, Fisk says, that in many cases, doctors can save their patients only by delivering babies early.

Researchers also rarely test drugs for common conditions such as depression on pregnant women, says Fisk, whose review of drugs under development was published in January in "PloS," a free online medical journal.

No new classes of drugs have been approved for conditions of pregnancy such as pre-term labor or a liver condition called cholestasis in the past two decades, Fisk says. The absence leaves obstetricians to use decades-old medications, making obstetrics "a specialty stuck in a time warp."

Most of the medications taken during pregnancy are prescribed "off label" for unapproved uses, Fisk says.

Linda Dona of Mount Vernon, Iowa, is due July 5 and also faces an early delivery — possibly this week — because of pre-eclampsia and cholestasis. Dona, 38, says she trusts that the hospital staff will give her baby the best of care.

She wishes she were as confident about off-label drugs she has taken throughout her pregnancy to treat Crohn's disease, an inflammatory condition that causes severe diarrhea, bloody stools and joint pain. One of her medications can cause birth defects in high doses; the other has never been tested in pregnant women, so doctors don't know how it will affect her child.

Without the medications, however, Dona's disease likely would flare up, causing a miscarriage.

"When I asked my doctors if these drugs are safe, they said, 'We just don't know. We don't have the data,' " Dona says.

Pharmaceutical company researchers would love to help women such as Dona and Candy, says Alan Goldhammer, deputy vice president of regulatory affairs for Pharmaceutical Research and Manufacturers of America. But companies also must consider the risks of exposing a developing fetus to experimental chemicals.

Given those concerns, experts says the "drug drought" isn't likely to end any time soon.

Worldwide, scientists are actively developing only 17 medicines for maternal health, Fisk says. That is less than 3 percent of the 660 drugs being developed for heart disease and half as many being researched for Lou Gehrig's disease, which affects only 5,600 new patients a year.

No new drugs made primarily for pregnant women are in clinical trials, which is the final phase of testing, Fisk says. On average, only about one drug in 10 makes it from early tests to final approval — a process that takes about a decade, Fisk says.

"We're not going to have a new drug in the next 10 years," he says.

PAST PROBLEMS

Researchers say history has taught them to be cautious about testing drugs on pregnant women.

The medication thalidomide, used to treat morning sickness in the late 1950s and early 1960s, caused severe limb deformities in babies. A drug used for morning sickness from the 1940s through the early 1970s, diethylstilbestrol, or DES, caused cancer in the daughters of women who took it.

Today, few pregnant women would sign up to test experimental drugs even if they were available, says Candy's doctor, Michael Greene, an obstetrician-gynecologist at Harvard Medical School and Massachusetts General Hospital.

Dona's doctor, Jennifer Niebyl, says she understands the need to protect children from birth defects. But Niebyl, head of obstetrics and gynecology at the University of Iowa Hospitals and Clinics, says few drugs have been found to increase these risks.

The real risks of developing drugs for pregnancy, Niebyl says, are financial. The market for drugs to treat conditions of pregnancy is relatively small, Fisk says. Relatively few women develop these conditions, and those who get sick need treatment for only a few weeks or months.

Companies can be ruined if their drugs are accused of causing birth defects even if a real link is never proven, Greene says.

In one famous example, manufacturer Merrell Dow Pharmaceuticals was sued by women who blamed their children's birth defects on its morning sickness drug, Bendectin, which combines vitamin B6 and a common antihistamine, doxylamine.

The company stopped selling Bendectin even though scientific tests found no increased risk of defects, says Sandra Kweder, deputy director of the Food and Drug Administration's office of new drugs.

But Bendectin's manufacturer wasn't the only one to suffer. Without Bendectin on the market, the number of pregnant women hospitalized for nausea and vomiting increased substantially, Kweder says.

Because so few drugs have been formally tested and approved in pregnancy, women don't know for sure how the medicines will affect them or their babies, Fisk says.

That leaves doctors and patients to weigh a drug's risks with its benefits, Greene says. "For many pregnant women, the bar gets raised for treatment," he says. "You ask, 'How bad is your headache? Do you really need this medication or can you live with it?' "

Often, doctors must choose between recommending a newer drug whose risks are unknown or an older, perhaps less effective one that has been used for several decades, Niebyl says.

Many doctors feel comfortable prescribing older drugs if they have a safe track record, she says. "It's the devil you know vs. the devil you don't know."

FDA officials say they're trying to get better answers. In May, they proposed overhauling the ways drugs are labeled for use during pregnancy and lactation to give women and their doctors a better idea of the risks and benefits.

The FDA also hopes to perform more studies, using a database that will include 100 million patients by 2012, Kweder says. Recent legislation also gives the FDA the power to require companies to study drugs in pregnant women and other "vulnerable populations" that haven't been well-researched.

The agency also works with pharmaceutical companies to study drugs used by pregnant women after they're approved, says Karen Feibus, medical team leader on the FDA's maternal health team.

These collaborations, called drug registries, avoid the ethical dilemmas of testing drugs on pregnant women by following only patients who already have decided to take a drug.

For example, a 15-year study of the drug acyclovir, used to treat herpes and chickenpox, helped prove it was safe to take during pregnancy.

WAYS TO HELP

Fisk argues that pregnant women shouldn't have to wait 15 years to learn if their medications are safe. But the government could help in other ways by providing incentives to study drugs during pregnancy, he says.

Existing incentives, for example, allow companies that test drugs in children to get longer patents for their products, Fisk says.

Companies that make drugs for rare diseases can get tax breaks. And those that make drugs for unmet medical needs, such as cancer and AIDS, can receive "fast-track" approval.

Dona says she hopes researchers are able to find a way to help families like hers.

"My husband and I had to make a moral and ethical decision and say, "Is it ethical to expose an unborn baby to these drugs when we don't have information about whether it will be harmful in the future?' " Dona says. "It's a leap of faith for anyone to have a baby, but we have more risks than most."