Brightsurf Science News and Current Science News Events
 
Email a Friend Send to a friend
Printer Friendly Print Nutrition a major factor in rise in twin pregnancies

Nutrition a major factor in rise in twin pregnancies

June 21, 2006

The commonly held view that IVF is the only culprit in the steady increase in the numbers of twins born over the past thirty years was challenged by a scientist speaking at the 22nd annual conference of the European Society of Human Reproduction and Embryology in Prague, Czech Republic, Wednesday 21 June 2006. Professor Robert Jansen, Medical Director of Sydney IVF, Sydney, Australia, said that his research had shown that improved nutrition, both maternal and in the lab in the case of IVF, had produced better and stronger embryos.

"Over the last 100 years, both in the UK and Australia, there has been an increase in identical twinning through the division of the embryo into two, even without IVF", he said, "and with the move to single embryo transfer with IVF this trend is obviously set to continue." Professor Jansen went on to say that the present rate of identical twinning with IVF is between one-in-a-hundred and one-in-fifty, a little over twice the rate involved when getting pregnant naturally.




Professor Jansen and his team reviewed Australian national birth statistics from 1920 to 2003 to determine the sex of babies at birth among multiple pregnancies. They found that the rate of dizygotic (DZ) twinning — where two embryos are involved and half the twins will be of different sex—was relatively constant from 1920 until the 1960s, but there was then the well-known dramatic increase with the advent of induced ovulation and IVF — reaching 300 in every 1000 IVF conceptions by 2000. Among monozygotic (MZ) twins, caused by embryo division (so all are of like sex), the excess rate of same-sex twins among natural conceptions has risen steadily for the last 80 years. MZ twins were relatively rare among IVF babies in the 1980s — much less than occurs naturally — but then rose in the nineties to reach 14 per 1000 by the year 2000.

"As IVF techniques improved there was a steady and substantial increase in MZ twinning, but starting from a low base — much lower than with natural conceptions", said Professor Jansen. "Our study shows for the first time that the increase we've seen coincides with improving culture conditions and that it started before any manipulation of the zona — the 'shell' of the egg — began. Transfer of just one embryo can therefore still lead to twins. If a higher rate of MZ twinning turns out to be a natural adaptation to improved nutrition or culture conditions, it could prove difficult to reverse as embryo quality continues to improve — whether in the IVF lab or in the community generally."

"Because two implanted embryos have twice the chance of MZ twins than a single implanting embryo the best way of minimising MZ as well as DZ twinning is to transfer one embryo at a time, irrespective of the age of the mother to be", he said.

In another other presentation to the conference, Mr. Graham Scotland, from the Health Economics Research Unit, University of Aberdeen, Aberdeen, UK, described how he and his colleagues had conducted work that throws light on why some couples prefer double embryo transfer (DET), despite being aware of the risks of twin pregnancy. His team assessed patients' preferences for a range of adverse birth outcomes associated with twin pregnancies — cerebral palsy, cognitive impairments, visual impairments, perinatal death — as well as a scenario in which treatment failed and they did not become pregnant. Participants were asked to read several cards describing the treatment outcomes and then asked hypothetical questions to elicit their preference value for each.

"The results showed that many women awaiting IVF appear to prefer the prospect of a chronic adverse birth outcome rather than childlessness", said Mr. Scotland. "Having no child at all was valued significantly lower than having a child with physical, cognitive or visual impairments, but significantly higher than perinatal death. Our work suggests that couples may need to be convinced that their chances of live birth with single embryo transfer are as high as they would be with DET, before they will voluntarily accept it."

European Society for Human Reproduction and Embryology



Related Twin Pregnancy News Articles
Size of a woman's uterus can predict whether she is at risk of having very premature twins after IVF
Using ultrasound to measure the height of a woman's uterus is a good way to predict whether or not she is at risk of having babies born prematurely if she becomes pregnant with twins after IVF.

Parents of twins report more mental health symptoms than parents of singletons
Mothers and fathers of twins conceived either spontaneously or with assisted reproductive technology (ART) suffer more mental health symptoms after delivery and one year later than do parents of singleton babies.

IVF technique enables pregnancy without multiple births, Stanford researchers find
An in vitro fertilization technique that can avoid multiple births appears to be effective for women older than 35, according to researchers at the Stanford University School of Medicine.

Progesterone therapy and preterm birth: More evidence helps identify women who can benefit
Two major studies published today in The New England Journal of Medicine can help doctors better identify pregnant women at risk for preterm delivery who can benefit from progesterone treatment, the March of Dimes Foundation said today.

Study identifies factors correlated with cerebral palsy
Several factors, including maternal infection during pregnancy, very preterm birth, and certain findings on brain MRI scans were correlated with cerebral palsy.
More Twin Pregnancy News Articles


When You're Expecting Twins, Triplets, or Quads, Revised Edition: Proven Guidelines for a Healthy Multiple Pregnancy
by Barbara Luke, Tamara Eberlein

The double whammy of successful infertility treatments and an increase in the number of women having children later in life has resulted in a staggering--but perhaps not surprising--phenomenon: a tremendous increase in twin, triple, and quadruple births. When Youčre Expecting Twins, Triplets, or Quads is an outstanding, much-needed addition to the pregnancy genre for women who face the...



Mothering Multiples: Breastfeeding and Caring for Twins or More! (La Leche League International Book)
by Karen Kerkhoff Gromada

A mother of multiple babies may find herself wondering if she can produce enough milk, how to coordinate feedings, and if breastfeeding is even an option for her. The simple answer: Yes! In the third revised edition of Mothering Multiples, author Karen Kerkhoff Gromada offers valuable information with an emphasis on breastfeeding and attachment-style parenting. All aspects of caring for multiple...



Twinspiration: Real-Life Advice From Pregnancy Through the First Year (for Parents of Twins and Multiples)
by Cheryl Lage

Twinspiration combines guidebook how-to with personal diary to lead mothers through pregnancy and the first year of their twins' lives. This carefully laid out book provides an array of information from the basics to the questions you are too afraid to ask with humor and honesty. This is the must have all in one resource for any couple that is expecting...



The Joy of Pregnancy: The Complete, Candid, and Reassuring Companion for Parents-to-Be
by Tori Kropp

Are you expecting... mystery, sensuality, wonder, and delight? If you are pregnant, you should be! Pregnancy isn't all about nausea and medical tests; it's also a time of excitement, anticipation, and above all, joy. You don t need to adopt a strict diet, adhere to a demanding exercise regimen, or spend your time worrying about planning the perfect birth. Rather, you can trust your instincts and...



Everything You Need to Know to Have a Healthy Twin Pregnancy
by Gila Leiter, Rachel Kranz

Twins...triplets...quads...finally! The book that answers all your questions about multiple birth--written by a doctor who is a mother of twins herselfOver ten years ago when Dr. Gila Leiter, herself an OB/GYN,was pregnant with twins, the book she desperately needed wasn'tavailable. Now it is: Everything You Need to Know to Have a Healthy Twin Pregnancy. Taking you step-by-step through the...



Oh Yes You Can Breastfeed Twins! ...Plus More Tips for Simplifying Life with Twins
by April Rudat

Book Description: From successful breastfeeding mother of twins April Rudat comes a practical, fun, and educational guide to breastfeeding and caring for multiples. "Oh Yes You Can Breastfeed Twins!" makes breastfeeding and parenting multiples a simpler feat with its up-to-date research and witty anecdotes. Packed with staple information for pregnant or new moms of multiples, "Oh Yes You Can...



Double Duty : The Parents' Guide to Raising Twins, from Pregnancy Through the School Years
by Christina Baglivi Tinglof

What lies ahead for expectant parents of twins? Immeasurable joy, plus many sleepless nights. Parenting twins is unlike parenting siblings of different ages. From infancy through the teen years, twins require a bit more energy and diplomacy, plus lots of clever ideas. Double Duty: The Parents' Guide to Raising Twins, from Pregnancy Through the School Years offers plenty of reassuring advice and...



Twins! 2e: Pregnancy, Birth and the First Year of Life
by Connie Agnew, Alan Klein, Jill Alison Ganon

The authors bill it as a "truly epic journey": the voyage from pregnancy through a lifetime of parenting twins. Perinatologists Connie L. Agnew, M.D., and Alan H. Klein, M.D. (also a pediatrician) incorporate a winning combination of helpful facts, educated opinion, and candid roundtable discussions--a combination that nicely maps the journey's first course for expectant parents of multiples....



The Multiple Pregnancy Sourcebook: Pregnancy and the First Days with Twins, Triplets, and More
by Nancy Bowers

Your reaction might have been something like this: "Hurrah! I'm pregnant! What? TWINS?!" Being pregnant with two (or more!) is different from being pregnant with one, and The Multiple Pregnancy Sourcebook tells it like it is, from weight gain to proper preparation for bringing your duplicate (or triplicate) bundles of joy home from the hospital. Author Nancy Bowers couldn't be more qualified...



Having Twins And More: A Parent's Guide to Multiple Pregnancy, Birth, and Early Childhood
by Elizabeth Noble

Now in a third edition, the best-selling guide on multiple births, Having Twins - and More, covers everything from conception through childhood.With ongoing advances in assisted reproduction, increasing numbers of women are having twins, triplets, and more, and they're having them later in life. Having Twins -- and More is the original source parents consult for guidance through the multiple...

© 2008 BrightSurf.com