How do pregnancy and childbirth affect fibroid growth and what to expect


Uterine fibroids are a common health concern among women, with an estimated 70 to 80% of women developing them by age 50. While the exact cause of fibroids is unknown, research suggests that there may be a link between fibroids and pregnancy, childbirth, and other reproductive factors.

For women who are planning to start a family or have already had children, understanding this connection can be essential for making informed decisions about their reproductive health. In this blog, we’ll explore the potential links between childbirth, pregnancy, and uterine fibroids, and what women should know to protect their health, wellbeing, and quality of life.

Research into these connections is still ongoing, and some findings may appear contradictory, but here’s what we know so far.


Does pregnancy cause fibroids to grow?

The answer to this question is complicated. For women who already have the condition, it appears that their fibroids do experience a hyper growth phase during the first trimester.

Researchers have found that fibroids “undergo a rapid and remarkable growth” during the first few months of pregnancy. Studies have found that fibroids “dramatically enlarge,” more than doubling within the first two months of gestation.

However, other studies have found that most (approximately 2 out of 3) women’s fibroids do not grow during pregnancy. But for those whose fibroids did grow, they increased in size extremely quickly.

 In all likelihood, your fibroids will not grow during pregnancy. It’s also extremely unusual for pregnancy to trigger the growth of fibroids for the first time. But, if you are part of the approximately one third of women whose fibroids do grow during pregnancy, you’ll likely experience a rapid increase in their size.


What happens when you are pregnant and have fibroids?

 Up to 10% of pregnancies are complicated by fibroids, which can lead to issues such as pain, heavy bleeding, and preterm labor. Women who have fibroids and are planning to become pregnant or who are currently pregnant should discuss their options with their healthcare provider to ensure the best possible outcome for both mother and baby.

 Most women with fibroids have regular pregnancies and deliveries, and fibroids may not cause any issues during pregnancy. But the potential effects of fibroids on pregnancy can vary depending on the location, size, and number of fibroids a woman has, as well as other individual factors.


 Effects of fibroids on pregnancy can include:


Fibroids may cause pelvic pain or discomfort during pregnancy, particularly if they are large or located in certain areas of the uterus.


Heavy bleeding

Spotting and heavy bleeding during pregnancy can be triggered by fibroids, particularly if they are located near the placenta.


Preterm labour

Fibroids may increase the risk of preterm labour or delivery, which can be dangerous for the baby.


Abnormal foetal position

The location of fibroids may cause the baby to be in an abnormal position in the uterus, which can increase the risk of complications during delivery.


Placental abruption

There is an increased risk of placental abruption, which occurs when the placenta separates from the uterus before delivery and can be life-threatening for both the mother and baby, associated with fibroids.

In some cases, fibroids may need to be monitored or treated during pregnancy to reduce the risk of complications. Treatment options may include medication to manage symptoms, surgical removal of fibroids, or in rare cases, early delivery by caesarean section.


Do fibroids shrink after childbirth?

Yes! Studies have discovered that more than 70 percent of women see their fibroids majorly shrink after they give birth – typically by more than 50 percent in size! Whether or not the women gave birth vaginally or via C-section, and whether or not they breastfed, had no impact on the shrinkage of the fibroids.

 This is likely due to the reduction of hormones such as oestrogen and progesterone in a woman’s body after delivery. However, the degree of shrinkage can vary depending on the size and location of the fibroids.

After delivery, the uterus goes through a process called involution, where it returns to its pre-pregnancy size. This process can cause fibroids to shrink, particularly if they are located within the uterine lining. However, fibroids located outside the uterine lining may not be affected by involution and may not shrink significantly.

 It’s worth noting that not all fibroids will shrink after childbirth, and in some cases, they may continue to grow or remain the same size. Additionally, if a woman has multiple fibroids or particularly large fibroids, they may not shrink enough to be noticeable.


I had a baby. Am I more at risk for fibroids?

 While we do know that fibroids often shrink in both volume and size after pregnancy, that doesn’t mean that your fibroids won’t eventually come back.

 It’s important to note that the relationship between childbirth and fibroids is complex and not yet fully understood. Other factors, such as genetics and lifestyle, may also play a role in the development of fibroids.

 The risk of developing new fibroids after pregnancy may be influenced by factors such as age, race, and family history. Women who have a family history of fibroids or who are African American may be more likely to develop fibroids, regardless of pregnancy status.

 If you have concerns about fibroids after giving birth, it’s important to discuss your individual risk factors with your healthcare provider. They can help you understand your risk and develop a plan for monitoring or treating fibroids if necessary, which is based on your individual circumstances.

Here at Talking Fibroids, our goal is to educate people about Uterine Fibroids and their symptoms. Find out more about us here or get in contact with us today!

Other topics you might be interested in See All
Other topics See All