Entries in Fertilization (4)


Selective Reduction: Couples Opting to Reduce Twins to Single Births

Keith Brofsky/Photodisc/Thinkstock(NEW YORK) -- Given the high cost and failure rate of fertility treatments, some couples try to increase their chances of getting pregnant by using multiple embryos during in vitro fertilization and end up facing an unexpected challenge of twins, triplets, or higher multiples -- a challenge some feel they cannot handle, emotionally or financially.

There is a way out of this challenge, but it is one that is seldom discussed among mommies-to-be: selective reduction.

In cases of high multiple pregnancies, doctors will often recommend selective reduction for purely medical reasons.  Early in the pregnancy, one or more of the fetuses are aborted from within the womb to increase the likelihood that the remaining babies (and the mother) will survive and thrive.

There are numerous health concerns to both mother and infants associated with carrying multiples.  Thus for decades obstetricians have offered the option of reducing down to twins, which tend to have safer outcomes.  This procedure can only be done with fraternal twins, as identical twins share a placenta and cannot easily be separated.

In the past years, however, some obstetricians and their patients have turned to selective reductions even in the case of twins -- not necessarily for medical reasons, but because the couple does not feel emotionally and/or financially prepared to have two babies when they had planned to have just one.

Fertility message boards such as are filled with parents-to-be discussing the moral dilemma of reducing to singletons, with many couples admitting that they reduced to one infant simply because they only wanted one.

New York City obstetrician and leading expert in selective reduction, Dr. Mark Evans, says that reductions from twins to a single fetus make up about 10 percent of the reductions he performs in his office, and that number is slowly increasing.

Evans wrote the recommendations on selective reductions 25 years ago, but at the time, he advocated for reductions only down to twins, barring extenuating circumstances.

"The rationale was that we knew that we could take care of twins and have good outcomes, and we were generally seeing couples with no kids.  So parents often wanted two or more kids ultimately anyway," says Evans.

But in 2004, Evans published a paper that overturned his past recommendations, arguing instead for the safety of reducing to singletons, even if the original pregnancy was only twins.

"The data forced me to change my opinion.  We now know that twins are not twice the risk of singletons, they are more like four times the risk.  For instance, there is a 1 in 700 chance of cerebral palsy with a single birth, but 1 in 100 with twins.  If you define success of a pregnancy as a healthy baby and a healthy mother, it's safer to reduce to singleton.  Women should be aware that this is a possibility," he says.

Though Evans argues that reducing twins is medically justifiable, this procedure remains highly contentious, especially considering that some couples admittedly choose to undergo reductions for personal, not medical reasons.

Copyright 2011 ABC News Radio


Taller Women More Likely to Have Twins after In Vitro?

Keith Brofsky/Photodisc/Thinkstock(AMSTERDAM) -- Multiple births after in vitro fertilization (IVF) are not uncommon, but a new study released on Monday suggests that if two embryos are implanted in a woman's uterus, taller recipients are more likely to have twins than their shorter counterparts.

Researchers at Vrije Universiteit Medical Centre in Amsterdam reviewed data from over 2,300 Dutch women who underwent a double embryo transfer during their first IVF treatment. They found that women measuring over five feet eight-and-a-half inches in height were almost three times more likely to give birth to twins than shorter women.

The authors of the study, however, could not offer any explanation to their findings.

Copyright 2011 ABC News Radio


Researchers Identify '15' as Magic Number for In Vitro Fertilization

Stockbyte/Thinkstock(LONDON) -- Women having difficulty conceiving often turn to in vitro fertilization, or IVF, to get pregnant.  But many times, it takes them several tries before they can get an implanted, fertilized egg to stick.

Researchers at King’s College London, however, have calculated that the ideal number of eggs that should be obtained at the start of the process in order to yield a live birth is 15.

The finding, published Tuesday in the journal Human Reproduction, was determined after the study's authors analyzed over 400,000 IVF cycles performed in the U.K. from 1991 to 2008.

Copyright 2011 ABC News Radio


In Vitro Fertilization Gives Couple Two Sets of Identical Twins

Keith Brofsky/Photodisc/Thinkstock(CHARLOTTE, N.C.) -- "Babies, babies, babies."  That's how Miranda and Josh Crawford now describe a typical day after their two sets of identical twins -- quadruplets in all -- joined their two-year-old sister in February.

After trying to get pregnant for more than a year, Miranda, 34, and Josh, 28, of Charlotte, North Carolina, turned to artificial insemination, and then in vitro fertilization, to have their first daughter.  Doctors implanted two embryos into Miranda's uterus, and one survived.  On March 17, 2009, Miranda gave birth to baby Joslyn.

But Miranda, 34, and Josh, 28, both registered nurses, hoped to eventually expand their family over time to three or four children.

A year later, the couple sought out in vitro fertilization for a second time.  Again, doctors transferred two embryos into Miranda's uterus, and, just six weeks into the pregnancy, doctors told the couple that they would be having twins.

But the ultrasound was fuzzy, and both the doctor and Miranda wanted to confirm how many babies were growing in her belly.  She returned to the hospital four days later.  This time, the ultrasound was clear -- there were four hearts beating on the screen, not two.

"I was shocked, the doctor was shocked," Miranda said.  "Never had that happened in his entire career."

Typically one or two embryos are inserted into a woman's uterus during one round of IVF.  Even then, the patient typically has a 60 percent chance of getting pregnant at all.  But both embryos had split in Miranda's uterus to create two sets of identical twins.

"For a woman who is less than 35 years old, it is recommended that one or two embryos be transferred into the uterus during a fresh IVF cycle," said Dr. Jani Jensen, a physician in the department of reproductive endocrinology and infertility at Mayo Clinic.  "In this case, it appears that the guidelines were correctly followed, but that lightning struck twice."

"This is certainly an unusual outcome," Jensen said.  "I've never seen it happen quite like this."

Jensen said she has rarely seen embryos split, but doctors estimate that it can happen in a little more than one percent of IVF cycles, and slightly more if the embryos are transferred as blastocysts, or embryos that have developed longer outside the body.

Copyright 2011 ABC News Radio

ABC News Radio