Ovarian follicles are small, fluid-filled sacs in theovaries, which are glands located on either side of theuterus.
The ovaries contain thousands of follicles, and each month one ruptures to release a mature egg.
If you are trying to conceive, your healthcare provider may recommend conducting tests to check your ovarian follicles.
SDI Productions / Getty Images
Certain health conditions affect the function of the follicle and may impact fertility.
Fortunately, there are treatment options available.
SDI Productions / Getty Images
What Is an Ovarian Follicle?
An ovarian follicle is a fluid-filled sac in theovary.
Each follicle contains one immature egg (oocyte).
Duringovulation, one of thousands of follicles ruptures and releases a mature egg.
When more than one follicle ruptures and releases an egg, the likelihood of twins increases.
The ovaries have two functions.
The first is to release an egg during ovulation.
The second is to releaseestrogenandprogesteronethroughout themenstrual cycle.
Most ovarian follicles never release a mature egg.
These follicles disintegrate, a process known as atresia.
Up to 99% of ovarian follicles disintegrate and never release a mature egg.
If your pelvic ultrasound shows multiple small cystic structures on your ovaries, this may be a normal finding.
These follicles develop during gestation and are known as primordial follicles.
As the ovarian follicles mature and grow, they become ready to release a mature egg.
Most follicles never reach this stage.
Follicular development, known asfolliculogenesis, has several stages:
How Many Follicles Does a Person Have?
The estimated number of follicles at birth varies significantly among studies.
Ovarian Follicles and Fertility
The function of the ovarian follicles significantly affects fertility.
To conceive a baby, your body must ovulate.
Ovulation comes up whenever an ovarian follicle matures and ruptures, releasing a mature egg.
If the egg becomes fertilized by sperm, a pregnancy may occur.
Once a person goes through menopause, their ovarian follicles no longer mature and release an egg each month.
Several symptoms can occur because the follicles no longer release the same amount of hormones as they used to.
Common menopause symptoms includehot flashes,night sweats, andvaginal dryness.
Fortunately, there are treatment options available.
This leads to a lack of mature eggs and fertility issues.
PCOS affects about 6% to 12% of people assigned female at birth who are of reproductive age.
Your healthcare provider can diagnose functional cysts with a pelvic ultrasound.
Some may resolve on their own, while others may require treatment.
Primary Ovarian Insufficiency
Primary ovarian insufficiencyoccurs when a persons ovaries fail and stop functioning before age 40.
People who have primary ovarian insufficiency have ovarian follicles that do not release a mature egg every month.
Ruptured Ovarian Cysts
Ovarian cysts are common, and most are harmless.
An ovarian cyst can break or rupture.
When a cyst ruptures, you may experience vaginal spotting,abdominal bloating, and sudden back pain.
Possible treatment options include:
Summary
Ovarian follicles are tiny, fluid-filled sacs in the ovaries.
Ovarian follicles contain immature eggs.
An ovarian follicle matures and ruptures each month to release a mature egg.
In addition to releasing mature eggs, ovarian follicles secrete estrogen and progesterone hormones.
Certain health conditions affect the function of ovarian follicles.
These include ovarian cysts, primary ovarian insufficiency, and PCOS.
Fortunately, there are several treatment options available.
National Cancer Institute.Definition of ovarian follicle.
American Society for Reproductive Medicine.Multiple pregnancy and birth: Twins, triplets, and high-order multiples.
2024;92:102430. doi:10.1016/j.bpobgyn.2023.102430
Office on Womens Health.Menopause basics.
2015;100(6):E845-E851.
doi:10.1210/jc.2015-1298
Centers for Disease Control and Prevention.Diabetes and polycystic ovary syndrome (PCOS).
Office on Womens Health.Polycystic ovary syndrome.
American College of Obstetricians and Gynecologists.Ovarian cysts.
National Institute of Child Health and Human Development.Primary ovarian insufficiency.
2020;159(1):R15-R29.
doi:10.1530/REP-19-0201
MedlinePlus.Primary ovarian insufficiency.
