NEW ORLEANS, Louisiana — Reducing carbohydrates and boosting protein intake can significantly improve a woman's chance of conception and birth after in vitro fertilization (IVF), according to a new study.
The effect is "at the egg level," said lead investigator Jeffrey Russell, MD, from the Delaware Institute for Reproductive Medicine in Newark. He presented the findings here at American Congress of Obstetricians and Gynecologists 61st Annual Clinical Meeting.
Carbohydrate-loaded diets create a hostile oocyte environment even before conception or implantation, he explained.
"Eggs and embryos are not going to do well in a high-glucose environment." By lowering carbs and increasing protein, "you're bathing your egg in good, healthy, nutritious supplements," he said.
Dr. Russell said this study was prompted by the poor quality of embryos he was seeing in young, healthy women who came through his IVF program. "We couldn't figure out why. They weren't overweight, they weren't diabetic," he said.
The 120 women in the study, who were 36 and 37 years of age, completed a 3-day dietary log. It revealed that for some, their daily diet was 60% to 70% carbohydrates. "They were eating oatmeal for breakfast, a bagel for lunch, pasta for dinner, and no protein," Dr. Russell explained.
Patients were categorized into 1 of 2 groups: those whose average diet was more than 25% protein (n = 48), and those whose average diet was less than 25% protein (n = 72). There was no difference in average body mass index between the 2 groups (approximately 26 kg/m²).
There were significant differences in IVF response between the 2 groups. Blastocyst development was higher in the high-protein group than in the low-protein group (64% vs 33.8%; P < .002), as were clinical pregnancy rates (66.6% vs 31.9%; P < .0005) and live birth rates (58.3% vs 11.3%; P < .0005).
When protein intake was more than 25% of the diet and carbohydrate intake was less than 40%, the clinical pregnancy rate shot up to 80%, he reported.
Dr. Russell now counsels all IVF patients to cut down on carbohydrate intake and increase protein intake.
"There is no caloric restriction, but they have to get above 25% protein. This is not a weight-loss program, it's a nutritional program. This is not about losing weight to get pregnant, it's about eating healthier to get pregnant," he said.
Back to Basics
In a study presented at the American Society of Reproductive Medicine (ASRM) meeting last year, IVF patients who switched to a low-carbohydrate, high-protein diet and then underwent another cycle increased their blastocyst formation rate from 19% to 45% and their clinical pregnancy rate from 17% to 83% (Fertil Steril. 2012;98[Suppl]:S47).
Even non-IVF patients with polycystic ovarian syndrome have improved pregnancy rates after making this lifestyle change, Dr. Russell noted.
This "draws attention to a previously understudied area of reproduction...and opens the way for understanding a host of dietary factors that may be related to improved outcomes in the assisted reproductive technologies," ASRM president-elect Richard Reindollar, MD, who is chair of obstetrics and gynecology at the Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire, told Medscape Medical News.
"These studies demonstrate how little we know about the effect of micronutrients in our diets on various aspects of reproduction. They demonstrate a field wide open for future research and beg questions such as whether, for example, it is carbohydrates in general or the inflammatory effects of gluten in grain carbohydrates that are deleterious to IVF outcomes," said Dr. Reindollar.
The study's connection between high blood glucose to IVF success is "an interesting finding that deserves to be evaluated further," said Sharon Phelan, MD, from the University of New Mexico in Albuquerque, who is a member of the ACOG Scientific Program Committee. She was asked by Medscape Medical News to comment on the findings.
"Although the blood glucose is not high enough to be in the diabetic range, it is enough to be toxic to the developing blastocyst," she added." Perhaps this is a call for us to get back to our 'roots,' or basic diets, again."
Dr. Russell, Dr. Reindollar, and Dr. Phelan have disclosed no relevant financial relationships.
American Congress of Obstetricians and Gynecologists (ACOG) 61st Annual Clinical Meeting: Abstract 96. Presented May 6, 2013.
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Cite this: Low-Carb Diet Improves In Vitro Fertilization - Medscape - May 08, 2013.