Uterine fibroids are extremely common — affecting up to 70% of women by age 50 — but their impact on fertility varies hugely depending on size, number and location. Understanding which fibroids matter for fertility helps you make informed decisions.
What Are Fibroids?
Fibroids (also called leiomyomas or myomas) are non-cancerous growths of the muscular wall of the uterus. They can range from microscopic to the size of a grapefruit or larger, and women can have one or many. Fibroids are classified by location: submucosal (inside the uterine cavity), intramural (within the uterine wall), and subserosal (on the outer surface). The location matters more than the size when it comes to fertility — submucosal fibroids have the biggest impact, while subserosal ones often cause no fertility problems at all.
How Fibroids Can Affect Fertility
Distortion of the uterine cavity: Submucosal fibroids can prevent embryo implantation by physically interfering with the uterine lining.
Blocked fallopian tubes: Large fibroids near the tubal openings may prevent sperm meeting the egg or stop a fertilised egg reaching the uterus.
Altered blood flow: Fibroids can disrupt blood supply to the uterine lining, affecting its receptivity to an embryo.
Inflammation: Some fibroids create a pro-inflammatory environment that may impair implantation and early pregnancy.
Increased miscarriage risk: Fibroids that distort the cavity are associated with higher rates of early pregnancy loss.
Pregnancy complications: Even fibroids that allow conception can increase risks of preterm birth, abnormal placental position and caesarean delivery.
Treatment Options When Trying to Conceive
Watchful waiting: Small, asymptomatic fibroids that do not distort the uterine cavity may simply need monitoring.
Hysteroscopic myomectomy: Day-case removal of submucosal fibroids through the cervix using a telescope. Best preserves fertility and recovery is fast.
Laparoscopic or open myomectomy: Surgical removal of intramural or subserosal fibroids while preserving the uterus. Recovery is longer and pregnancy may need to be delayed 6-12 months.
Uterine artery embolisation (UAE): Generally not recommended if you want children, as it can affect ovarian blood supply.
MRI-guided focused ultrasound: Newer non-invasive option, but data on subsequent fertility is limited.
Medication: GnRH agonists shrink fibroids temporarily but cannot be used long-term and fibroids regrow when stopped.
When to Seek Specialist Advice
You have been trying to conceive for 6-12 months without success and have known fibroids
You have heavy or painful periods alongside difficulty conceiving
You have had recurrent miscarriage and fibroids have been identified
A fibroid is found on ultrasound that distorts the uterine cavity
You are over 35 with fibroids and considering trying for a baby
Educational information, not medical advice. For advice about your own situation, talk to your doctor.