Amy Lembcke once dreamed of twin babies -- of using aggressive in-vitro fertilization to overcome infertility and conceive her family in one swoop.

But when the time came to pursue IVF, Lembcke backed off. She didn't want to risk the money or toll on her body for a procedure that could produce a baby, or no baby, or more babies than she bargained for.

"I didn't want to take out a loan or a second mortgage on the house just to try to have a baby," said Lembcke, 29, of St. Paul, "because they come with their own expenses."

Lembcke's change of heart helps explain a surprising turnaround in Minnesota -- a decline in multiple births from 2,599 babies in 2009 to as few as 2,297 last year. Multiple births had increased almost every year for the past two decades, mostly because of the popularity of assisted reproduction techniques such as IVF -- by which embryos are fertilized outside the body and then implanted in infertile women.

So while the decline in multiple births is small, it is significant. Public health and fertility experts suspect that the struggling economy discouraged couples such as the Lembckes from pursuing expensive fertility treatments. (IVF can cost around $15,000, and insurance coverage of the procedure is spotty.)

But the decline also marks improvements in infertility procedures; Minnesota's five IVF clinics are all reporting more pregnancies over the past decade but fewer twin and triplet births.

Preliminary figures from the Minnesota Department of Health for 2012 show no quadruplets or higher order births and only 65 babies born as triplets -- a decline from 92 in 2009 and well shy of a high of 167 in 2001. The data also showed fewer twin births, which surprised fertility doctors because many of their patients want twins.

"We've done a very good job at almost eliminating the triplets," said Dr. Jacques Stassart, medical director of Reproductive Medicine and Infertility Associates, which provides IVF in Edina and Woodbury. "The next frontier is to curb the number of twins, though we're meeting a bit of patient resistance to that."

The trouble with twin births is that they double the risk of babies being born prematurely or with birth defects that can result in lifelong disabilities. A sustained decline in multiple births could have significant cost savings for Minnesota's health care system because fewer newborns would need costly neonatal intensive care.

"It's not completely wrong" to want twins, said Dr. Eric Widra, an IVF provider in Washington, D.C., and the chairman of the practice committee for the U.S. Society for Assisted Reproductive Technologies. "If the kids do well, then you have two kids. And if that's how you see your family, then you get a lot of the hard work out of the way early. But from a public health standpoint, you have to look at the differences in risk and the differences in cost."

Reversal of a trend

Last January, a federal study reported record twin births in the United States, but it was based on 2009 data. Now 2010 figures are out for the nation and -- like the Minnesota figures -- they show a decline in twin and triplet births.

"I don't know if it will continue or not, but it's important because the rate had been going up fairly steadily," said Joyce Martin, a birth trends researcher for the National Center for Vital Statistics.

The economy has been linked to a decline in births overall that started with the 2008 recession. Minnesota births declined from 73,664 in 2007 to 66,330 last year. But since 2009, the number of multiple births has declined 12 percent while total births only declined 6 percent.

After trying with her husband for a couple of years to have a baby, Lembcke was diagnosed with a hormone imbalance that made her infertile. She became fixated on ways to get pregnant. The notion of a multiple birth was hardly a concern.

"We did fertility treatments for about six months," she said. "I tend to be overly involved when I'm doing things, and it became too much for me. It took a toll on my marriage. It changes who you are."

Lembcke also worried about the physical toll of taking hormone drugs to produce eggs for the IVF process. So she instead searched for ways through diet and exercise to correct her hormone imbalance and improve her chances of pregnancy.

"It's not about getting pregnant at all costs," she said. "It's about starting a family."

Stassart believes the decline in multiple births is due to improvements in assisted reproduction and fertility specialists recommending more conservative attempts to patients.

Fewer embryos implanted

In 2001, nearly half the women 35 and younger who got pregnant through IVF at Stassart's clinic had multiple births. By 2010, only one-third of those pregnancies resulted in twins or more.