Fibroids are found in a significant minority of pregnant women, and the great majority of those pregnancies proceed normally. Whether a fibroid matters depends on where it is, how big it is and how it behaves as the uterus grows.
What happens to fibroids in pregnancy
Pregnancy hormones can cause fibroids to enlarge, particularly in the first half of pregnancy; most then stabilise or shrink. Occasionally a fibroid outgrows its blood supply, causing a painful episode called red degeneration — distressing, but managed with rest and pain relief and not harmful to the baby.
Possible complications
These are more likely with large fibroids (over 5 cm) or fibroids inside the cavity or near the placenta:
- Pain from degeneration
- A slightly higher risk of miscarriage and preterm birth
- Breech or transverse position of the baby if a fibroid occupies the lower uterus
- Placental problems if the placenta implants over a fibroid
- A higher chance of caesarean delivery and of heavier bleeding after delivery
How fibroids are monitored in pregnancy
Fibroids are mapped at the early scans, and growth scans in the third trimester check the baby's growth and position. Most women need no additional treatment. Fibroids are not removed during pregnancy or at caesarean section, except in unusual circumstances, because of the bleeding risk.
Delivery
Normal delivery is possible for most women with fibroids. A caesarean is planned if a fibroid blocks the birth canal, the baby is in an abnormal position, or there are other obstetric reasons. Your obstetrician will discuss the plan well before term.
If you are planning pregnancy and have fibroids
This is the time to have them assessed. Submucosal fibroids (inside the cavity) and large intramural fibroids can reduce fertility and raise miscarriage risk, and removing them before pregnancy — usually by hysteroscopy or laparoscopy — may be recommended. Small, subserosal fibroids usually need no treatment. See fibroid treatment and high-risk pregnancy care.
Have a question about this topic? Dr. Bhavya Rathore consults at her Indirapuram clinic (Gyan Khand 4) and at Cloudnine Hospital. Book a consultation or message the clinic on WhatsApp.
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Medical disclaimer: This page is for general information and does not replace a consultation. It is not individual medical advice, and outcomes vary from person to person. If you have urgent symptoms — heavy bleeding, severe pain, fever, fainting or reduced baby movements — contact the clinic or go to the nearest emergency department immediately. Read the full disclaimer.