Study uncovers how 'good cholesterol' levels may influence pregnancy

April 30, 2014, University at Albany
Study uncovers how ‘good cholesterol’ levels may influence pregnancy
Left and right side ultrasounds of ovaries with developing follicles.

(Medical Xpress)—University at Albany epidemiologist Michael Bloom and three fellow researchers have released a study on how the "good cholesterol" may play a role within the ovarian follicle in pre-programming an egg for successful pregnancy or failure.

The report, published online in the journal Fertility and Sterility, studies variability in the components of high-density lipoprotein (HDL) between follicles within a woman and how this variation relates to differences in levels between different women. Human 'follicular fluid' that bathes an immature egg cell (oocyte) is a complex mixture of lipids, proteins, hormone, micronutrients and other molecules. HDL is the only lipoprotein identified in this follicular fluid.

Along with UAlbany Ph.D. candidate Keewan Kim, reproductive endocrinologist Victor Y. Fujimoto of the University of California, San Francisco (UCSF), and University at Buffalo (UB) biochemist Richard W. Browne, Bloom collected the follicular fluid from two in each of 171 women undergoing in vitro fertilization for treatment of infertility at UCSF. At UB laboratories, levels of various HDL-particle components were measured.

"Using statistical analysis we found that the variation in HDL-particle components within a woman was frequently greater than the variation between different women, suggesting that each ovarian follicle was a chemically and metabolically active 'mini-organ'" said Bloom, a member of the School of Public Health's Department of Environmental Health Sciences. "In other words, each follicle appeared to actively create a unique 'micro-environment' for the developing egg."

Furthermore, the researchers found that the extent of this variability was different according to age, body mass, cigarette smoking, race and infertility diagnosis—factors that predict the likelihood for a woman to deliver a live baby following in vitro fertilization (IVF). Given the societal dilemma of reproductive choice with advanced maternal age as well as the increasing evidence of the influence of environmental exposures upon reproductive physiology, greater understanding of the role that the HDL-particle plays in the health of the human ovarian follicle and the oocyte may be critically important.

"To our knowledge, this is the first indication of the importance of follicular fluid HDL particle variability within a woman in assisted human reproduction, rather than just differences between women," said Bloom.

"Understanding what makes an egg healthy or not is critical to improving the opportunity for women desiring to conceive," said Fujimoto, who directs UCSF's Vitro Fertilization Program. With the study's results suggesting that the metabolic activity of the ovarian follicle influences oocyte competence, it may offer an opportunity for clinical intervention in the future, to improve the live birth rate following IVF.

According to Bloom, the study has implications for the design of future analysis examining parameters as predictive markers of IVF success or failure. The next step will be to examine the impact of this variability on oocyte fertilization, embryo development, pregnancy and live birth following IVF among the women in the study.

The group's work is part of a larger study supported by the U.S. National Institute of Aging/National Institutes of Health, designed to better define the physiology of human ovarian follicle metabolism, and the manner in which cholesterol influences the developmental potential of the human oocyte and embryo.

Explore further: Study shows male hormones play an important role in female fertility

Related Stories

Study shows male hormones play an important role in female fertility

March 4, 2014
(Medical Xpress)—Several fertility clinics across the country are beginning to administer testosterone, either through a patch or a gel on the skin, to increase the number of eggs produced by certain women undergoing in ...

Elevated mercury, cadmium block in-vitro pregnancy

July 19, 2012
(Medical Xpress) -- A new University at Albany study finds background exposure to levels of mercury and cadmium commonly found in the environment may significantly interfere with early pregnancy through in-vitro fertilization ...

Miscarriage risk increases for women who respond poorly to IVF ovarian stimulation

March 24, 2014
(Medical Xpress)—Women who respond to IVF treatment with low numbers of eggs are at increased risk of miscarriage, a study co-authored by University of Birmingham researchers has found.

Researchers shed new light on egg freezing success rates

May 29, 2013
Researchers from New York Medical College and the University of California Davis have for the first time codified age-specific probabilities of live birth after in vitro fertilization (IVF) with frozen eggs. A team of researchers ...

Standard IVF medication dose less effective in obese women

March 20, 2014
Obese women may need a different dose of medication than normal weight women in order to successfully have their eggs harvested for in vitro fertilization (IVF), according to a new study published in the Endocrine Society's ...

Study prompts rethink of how ovaries develop

February 8, 2013
(Medical Xpress)—New research from the University of Adelaide will rewrite the text books on how an ovary is formed, as well as providing new insights into women's health and fertility.

Recommended for you

Rise in preterm births linked to clinical intervention

January 18, 2018
Research at the University of Adelaide shows preterm births in South Australia have increased by 40 percent over 28 years and early intervention by medical professionals has resulted in the majority of the increase.

New report calls into question effectiveness of pregnancy anti-nausea drug

January 17, 2018
Previously unpublished information from the clinical trial that the U.S. Food and Drug Administration relied on to approve the most commonly prescribed medicine for nausea in pregnancy indicates the drug is not effective, ...

New study finds 'baby brain' is real, but the cause remains mysterious

January 15, 2018
So-called "baby brain" refers to increased forgetfulness, inattention, and mental "fogginess" reported by four out of five pregnant women. These changes in brain function during pregnancy have long been recognised in midwifery ...

Sleep quality improves with help of incontinence drug

January 12, 2018
A drug used to curtail episodes of urinary incontinence in women also improves quality of sleep, a researcher at the Stanford University School of Medicine reports.

Frozen embryos result in just as many live births in IVF

January 10, 2018
Freezing and subsequent transfer of embryos gives infertile couples just as much of a chance of having a child as using fresh embryos for in vitro fertilization (IVF), research from Ho Chi Minh City, Vietnam, and Adelaide, ...

Study suggests air pollution breathed in the months before and after conception increases chance of birth defects

January 8, 2018
A team of researchers with the University of Cincinnati and Cincinnati Children's Hospital has found evidence that indicates that pre-and post-pregnant women living in an area with air pollution are at an increased risk of ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.