Fibroids During Pregnancy
Why This Matters
Finding out you have fibroids during pregnancy can be worrying.
Perhaps they were discovered during your routine dating scan, or maybe you already knew you had fibroids before becoming pregnant.
It's natural to wonder:
Will my baby be okay?
Will the fibroids keep growing?
Will I miscarry?
Will I need a Caesarean section?
While fibroids can sometimes increase the risk of certain pregnancy complications, it's important to remember that most women with fibroids have healthy pregnancies and healthy babies.
Understanding how fibroids may affect pregnancy can help you know what to expect and when you might need extra monitoring.
Quick Summary
Most women with fibroids have healthy pregnancies.
Fibroids often grow during early pregnancy because of hormonal changes.
Some women experience pain as fibroids outgrow their blood supply.
The size, number and location of fibroids influence the likelihood of complications.
Your maternity team may recommend additional monitoring.
Many women with fibroids have straightforward vaginal births, while others may need a Caesarean section depending on their individual circumstances.
What Happens to Fibroids During Pregnancy?
Pregnancy hormones, particularly oestrogen and progesterone, can encourage fibroids to grow.
Fibroids are most likely to increase in size during the first half of pregnancy.
However, not all fibroids grow, and some remain unchanged throughout pregnancy.
After your baby is born, many fibroids gradually become smaller as hormone levels return to normal.
Will My Baby Be Harmed?
In most cases, no.
Most fibroids do not affect the baby's growth or development.
Your baby continues to receive oxygen and nutrients through the placenta, and many pregnancies progress normally despite the presence of fibroids.
Your healthcare team will monitor your pregnancy if they feel the fibroids could affect your baby's position or the course of your pregnancy.
Can Fibroids Cause Miscarriage?
Some studies suggest that certain fibroids, particularly those that distort the inside of the uterus, may increase the risk of miscarriage.
However, many women with fibroids have successful pregnancies without experiencing miscarriage.
Your overall risk depends on several factors, including:
where the fibroids are located
how large they are
how many fibroids you have
whether there are other pregnancy or fertility factors
Pain During Pregnancy
Pain is one of the most common complications associated with fibroids during pregnancy.
This often occurs because the fibroid grows more quickly than its blood supply can support.
As a result, part of the fibroid may begin to break down, a process known as red degeneration (or carneous degeneration).
Symptoms may include:
sudden abdominal pain
tenderness over the uterus
fever (occasionally)
nausea or vomiting
Although this pain can be severe, it usually settles with rest, fluids and appropriate pain relief recommended by your healthcare team.
Can Fibroids Affect My Baby's Position?
Sometimes.
Large fibroids may reduce the amount of space available inside the uterus.
This can increase the chance that your baby is:
breech (bottom first)
lying sideways (transverse position)
If this happens, your maternity team will discuss the safest way to deliver your baby.
Can Fibroids Cause Premature Labour?
Some studies suggest fibroids may slightly increase the risk of:
premature labour
premature rupture of membranes
preterm birth
However, many women with fibroids carry their pregnancies to full term.
Your healthcare provider will advise if additional monitoring is appropriate.
Will I Need a Caesarean Section?
Not necessarily.
Many women with fibroids have successful vaginal births.
However, a Caesarean section may be recommended if:
a fibroid blocks the birth canal
your baby is breech or lying sideways
labour isn't progressing normally
there are other obstetric reasons
The decision is based on your individual pregnancy rather than the presence of fibroids alone.
Can Fibroids Affect the Placenta?
In some cases, fibroids may affect where the placenta implants.
Rarely, this can increase the risk of:
placental abruption (where the placenta separates too early)
placenta lying close to a fibroid
bleeding during pregnancy
These complications are uncommon, but your healthcare team will monitor your pregnancy if needed.
What Happens After the Baby Is Born?
After delivery, hormone levels begin to fall.
Many fibroids gradually shrink during the months after pregnancy.
Your healthcare provider may recommend a follow-up appointment if:
your fibroids caused symptoms during pregnancy
you're continuing to experience heavy bleeding
you're considering another pregnancy
What Does This Mean for You?
Hearing that you have fibroids during pregnancy can be frightening, but it's important to remember that most women go on to have healthy pregnancies and healthy babies.
Your maternity team will consider:
the size of your fibroids
where they are located
whether they're causing symptoms
how your baby is growing
Most pregnancies progress well with routine care, while some women may benefit from a little extra monitoring.
You Are Not Alone
It's understandable to feel anxious when you're told there's something "extra" in your uterus during pregnancy.
Many women immediately worry about losing their baby or needing major surgery.
While those fears are completely natural, remember that fibroids are common, and most women with fibroids experience positive pregnancy outcomes.
If you're worried, don't be afraid to ask your midwife or obstetrician questions. Understanding what's happening can often help ease some of the uncertainty.
Questions to Ask Your Doctor or Midwife
Where are my fibroids located?
Are they likely to affect my pregnancy?
Will I need additional ultrasound scans?
Could my fibroids affect my baby's position?
What symptoms should prompt me to seek urgent medical advice?
Is a vaginal birth likely to be possible?
Will my fibroids shrink after pregnancy?
Should I arrange follow-up after my baby is born?
Myth vs Fact
Myth
Fact
Having fibroids means I'll lose my baby.
Most women with fibroids have healthy pregnancies and healthy babies.
Fibroids always keep growing throughout pregnancy.
Some grow during early pregnancy, while others stay the same or even shrink later.
Every woman with fibroids needs a Caesarean section.
Many women have safe vaginal births.
Fibroids harm the baby.
Most fibroids do not affect the baby's growth or development.
Your Next Step
If you've recently been told you have fibroids during pregnancy:
Ask where your fibroids are located.
Find out whether they're likely to affect your pregnancy.
Keep all your antenatal appointments.
Seek medical advice promptly if you develop severe abdominal pain, heavy bleeding, reduced fetal movements (later in pregnancy), or think you may be in labour early.
Remember, every pregnancy is different. Your healthcare team is there to support you and guide you through any additional monitoring that may be needed.
Key Takeaways
Most women with fibroids have healthy pregnancies.
Fibroids may grow during early pregnancy because of hormonal changes.
Pain caused by degeneration is one of the most common pregnancy-related fibroid complications.
Fibroids may slightly increase the risk of miscarriage, preterm birth and breech presentation, depending on their size and location.
Many women with fibroids have successful vaginal births.
Regular antenatal care helps monitor both you and your baby.
Frequently Asked Questions
Can fibroids grow during pregnancy?
Yes. Many fibroids increase in size during the first half of pregnancy because of rising hormone levels, although not all do.
Will my baby be affected by my fibroids?
Usually not. Most babies develop normally, even when fibroids are present.
Can fibroids cause pain during pregnancy?
Yes. Pain can occur if a fibroid outgrows its blood supply and undergoes degeneration. This should always be assessed by your healthcare provider.
Will I need a Caesarean section?
Not necessarily. Many women with fibroids have vaginal births. A Caesarean section is recommended only if there is a medical reason.
Do fibroids shrink after pregnancy?
Many do. As hormone levels fall after birth, fibroids often become smaller over the following months.
Related Articles
Fibroids Explained
Symptoms of Fibroids
Fibroids and Fertility
Can You Get Pregnant with Fibroids?
Treatment Options for Fibroids
Fibroids and Heavy Periods
Pregnancy After Myomectomy(future article)
References
National Institute for Health and Care Excellence (NICE). Antenatal Care and Heavy Menstrual Bleeding: Assessment and Management (NG88).
Royal College of Obstetricians and Gynaecologists (RCOG). Fibroids: Information for You.
American College of Obstetricians and Gynecologists (ACOG). Uterine Fibroids.
Society for Maternal-Fetal Medicine (SMFM). Guidance on pregnancy with uterine fibroids.
Stewart EA, et al. Uterine Fibroids. Nature Reviews Disease Primers.
Bulun SE. Uterine Fibroids. New England Journal of Medicine.
When to Seek Urgent Medical Advice
Most women with fibroids have healthy pregnancies. However, you should contact your midwife, maternity unit or seek urgent medical advice if you experience:
Heavy vaginal bleeding.
Severe or persistent abdominal pain.
A high temperature (fever) or feel generally unwell.
Leaking fluid from your vagina.
Regular contractions before 37 weeks of pregnancy.
Reduced or absent baby movements (once you've started feeling regular movements).
Severe dizziness, fainting or difficulty breathing.
Any symptom that makes you feel something isn't right.
It's always better to seek advice and be reassured than to stay at home worrying. Your maternity team would much rather assess you than have you struggle in silence.