MAR 14, 2019 10:10 AM PDT

Understanding Why Birth Control Can Fail

WRITTEN BY: Carmen Leitch

While birth control pills are usually effective at preventing pregnancy, there is a small risk that they’ll fail. That’s been blamed on user error - forgetting to even one pill on time could reduce its efficacy. New research has indicated that other factors may be at work, however. Scientists have identified a small change or variation in a gene that encodes for an enzyme, which can break down hormones that are often used in contraceptives. The gene is only supposed to be expressed in childhood. But the research, reported in Obstetrics & Gynecology, suggests that a small percentage of women with a variant of that gene continue to produce that enzyme into adulthood.

Birth control pills / Adapted from: Gabriela Sanda/Pixabay

"The findings mark the first time a genetic variant has been associated with birth control," said the lead author of the report Aaron Lazorwitz, MD, an assistant professor of Obstetrics and Gynecology at the University of Colorado School of Medicine.

In this research, the scientists assessed data from 350 healthy women that had a contraceptive implant for at least twelve and up to 36 months. They found three genetic variants in the participants. One of the variants, CYP3A7*1C, initiated the expression of a protein normally expressed in infanthood, CYP3A7. That protein is an enzyme that can change the metabolism of hormones. 

The researchers suggested that women carrying this gene variant might break down birth control hormones so quickly that it renders their contraception ineffective. Carriers of the variant were found to have birth control levels that were too low to suppress ovulation consistently.

"That enzyme breaks down the hormones in birth control and may put women at a higher risk of pregnancy while using contraceptives, especially lower dose methods," Lazorwitz explained. "When a woman says she got pregnant while on birth control the assumption was always that it was somehow her fault. But these findings show that we should listen to our patients and consider if there is something in their genes that caused this."

Pharmacogenomics is a burgeoning field that shows how the gene sequences a person carries affects their response to drugs. It has the potential to transform healthcare, and women’s health dramatically. The study authors note that these findings, in particular, can have important consequences; unintended pregnancies can have huge ripple effects.

Lazorwitz is hopeful that this work will help create precise medicine that can help meet individual patient needs.

"As more genetic data becomes available, clinicians may need to consider adding genetic predisposition to increased steroid hormone metabolism in their differential diagnosis for unintended pregnancies in women reporting perfect adherence to hormonal contraceptive methods," he said.

Learn more about pharmacogenomics from the video above by Mayo Clinic.


Sources: AAAS/Eurekalert! via University of Colorado Anschutz Medical Campus, Obstetrics & Gynecology

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
NOV 22, 2021
Cell & Molecular Biology
Understanding an Unusual Receptor That's Linked to Depression
NOV 22, 2021
Understanding an Unusual Receptor That's Linked to Depression
Clinical depression is estimated to impact over 264 million people worldwide in any given year, but it's difficult to tr ...
DEC 16, 2021
Cell & Molecular Biology
How Exercise May Help Protect Against the Effects of Aging
DEC 16, 2021
How Exercise May Help Protect Against the Effects of Aging
There's plenty of evidence that when possible, it's more healthy for people to stay physically active than it is for the ...
DEC 26, 2021
Genetics & Genomics
Researchers Make a Breakthrough & Edit Genes in a Deadly Fungus
DEC 26, 2021
Researchers Make a Breakthrough & Edit Genes in a Deadly Fungus
Candida auris emerged as a pathogen around 2009, and has quickly become a serious problem for clinics and hospitals, whe ...
JAN 04, 2022
Immunology
Scientists Win a Game of Bacterial Hide-And-Seek
JAN 04, 2022
Scientists Win a Game of Bacterial Hide-And-Seek
When infection strikes, antibiotics are the go-to solution to help patients regain control from the invading bacter ...
JAN 11, 2022
Clinical & Molecular DX
Benign Kidney Tumors Linked to Type 2 Diabetes
JAN 11, 2022
Benign Kidney Tumors Linked to Type 2 Diabetes
Up to 10 percent of the population have benign lumps on their adrenal glands, triangular hormone-secreting glands that s ...
JAN 11, 2022
Cell & Molecular Biology
With the Right Form, a More Functional Organoid is Built
JAN 11, 2022
With the Right Form, a More Functional Organoid is Built
In biology, it's sometimes said that form follows function; the shape of a protein can have a major impact on how it wor ...
Loading Comments...