CRM : Center For Reproductive Medicine

By Rosemary Banks Harris for the Orlando Sentinel
May 14, 1990

Cheryl Koerner's mother, Phyllis, could tell just by looking: Cheryl was going to have twins.

The first sonogram confirmed her mother's lay medical analysis: two little heads were present. A subsequent X-ray showed only one baby, leaving Cheryl and husband Richard to wait in limbo right up until the hour Theresa and Phillip - healthy fraternal twins - entered the world.

Three years later Cheryl and Richard Koerner's Orlando household was again expecting a new baby. This time the doctors thought the sonograms were conclusive. It's only one baby, they said.

Shaun and Shane Koerner - fraternal twin boys - are now 8 years old. Their sister Marcia, 13, just wishes she had been a twin too.

The Koerners - Cheryl is a homemaker; Richard manages an Orlando microfilm lab - are part of a nationwide boom in twins and other multiple births.

In the past 10 years the number of multiple births in the United States has more than doubled. There are now 22 twin births per 1,000 births - or about 2 percent, according to the National Center for Health Statistics, a division of the U.S. Public Health Service.

The number of triplets also has jumped significantly - to one triplet birth for each 8,000 babies born. Twenty years ago triplet births were even more of a rarity than they are now.

In the United States an estimated 50,000 women had twins in 1989 - more than 4,000 in Florida alone. In the state, according to the Florida Department of Health and Rehabilitative Services, there were an estimated 84 triplet and other multiple births. Nationwide, triplets and other multiples were born to about 2,300 mothers last year.

Experts cite these reasons for the increase in multiple births:

• More women are waiting longer to have children, postponing marriage and child-rearing until they have reached their educational or career goals. As first-time mothers pass 30, they are more than four times more likely to have twins than younger mothers.
• More couples are using fertility drugs, dramatically increasing their chances of having a multiple birth.
• A "mini-baby boom" is increasing the number of annual births, raising the number of multiple births as well.

"We have steadily charted an increase in multiple births," said Stephanie Ventura, a demographer with the national health center. "A big part of the twin boom is first-time mothers who are aged 33 to 39. These women are having multiple births at unprecedented rates. Not just twins, but triplets - even quadruplets."

As women pass 30, their bodies produce more follicle-stimulating hormone, which is central to ovulation. The hormone stimulates the follicles, allowing eggs to be released.

Production of the hormone also increases when a woman, who has taken the birth control pill for many years, quits taking the pill to have a baby - an occurrence common to many women over 30.

Doctors usually recommend that women who have been on the pill use an alternative form of birth control for three to six months before trying to become pregnant. Doing so makes a prospective mother healthier and can decrease the chance that an older mother will have twins.

But there are those mothers who know they have a high chance of giving birth to twins because they take fertility drugs to help them conceive.

"Clomid (the most popular fertility pill) gives couples a 5 to 10 percent greater chance of conceiving twins and a greater risk of other multiple births," said Dr. Gary W. Devane, a Winter Park infertility specialist.

"There are even more powerful fertility drugs but a common side effect of all certainly includes the risk of multiple births."

Devane estimates that 25 percent of all women over 30 might need a fertility drug to assist in conception because many don't ovulate properly as they get older. Because so many women are over 30 when they first consider pregnancy - and because so many use fertility drugs - it would follow that the drugs are a particular culprit in the multiple-birth rise.

Still, Ventura of the health center, said twin and triplet births will continue to increase, with or without drugs. "The number of births last year was the highest it's been since 1954 - more than 4 million babies were born in 1989. The number of babies born has been increasing about 3 percent each year since 1986. "The numbers are slowly increasing so twin births are going to increase as well," she said.

Cheryl Kroener said she won't chance another pregnancy.

"At my age, and with my genes," she said. "More twins would be almost inevitable."