Part II: Can Fibroids Affect My Pregnancy?
By Alicia Armeli


You’re having a baby—and you have fibroids. With the endless amount of information you’re absorbing in preparation for your little one, you may now also be wondering how fibroids could affect your pregnancy.

Fibroids have been reported in approximately 0.1-11 percent of all pregnancies and become more common in women 35 years and older, those who’ve never had children, and among African Americans.1

Although the majority of women with fibroids will have a smooth pregnancy, between 10-40 percent of women will experience complications.1 Facing this reality, it’s important to build awareness around the possible effects these benign tumors can have on a pregnancy in order to receive appropriate care.

Nearly 75 percent of fibroids increase in size during the first and second trimesters and 66 percent during the second and third trimesters. “The increased estrogen and progesterone during pregnancy can result in increased growth which can become problematic in about 5 percent of pregnant women with fibroids,” said Dr. Mark Perloe MD, an infertility specialist and Medical Director at Georgia Reproductive Specialists in Atlanta.

And although fibroids are seen to reduce in size for the majority of women by 50 percent after giving birth, until this occurs, they can be painful and cause pressure on the uterus.1

“Most physicians look at fibroids during pregnancy as a pressure effect,” explained Dr. Perloe. “If the fibroid is cutting down on the blood supply to the uterus by pressing on arteries or causing engorgement in the uterine lining because it’s pressing on the veins that return blood to the uterine lining, this could potentially bring about a miscarriage. Also, larger fibroids may impair the blood supply to the fetus so that growth is retarded or delayed and you have a smaller baby as a result.”

Other complications can include premature labor, postpartum bleeding, the baby being in the wrong position at birth—as seen with breech births, and an increased need for cesarean section.1

But complications and risk of pregnancy loss are significantly linked to several fibroid characteristics like number, location, and size.

A small study published by the American Journal of Obstetrics & Gynecology2 observed 121 women with fibroids between 2002 and 2012. Through ultrasound exam, Lam and colleagues noted the size, location, and number of fibroids in each woman. The authors then compared this information to a total of 179 pregnancy outcomes verified through the women’s medical records.

Results indicated that complications like preterm delivery were more common among women with multiple fibroids. Fibroids located in the lower part of the uterus were associated with the need for cesarean section. And in addition to location, larger fibroids were consistent with postpartum bleeding.

Other studies have shown that fibroids specifically growing into the uterine space or within the uterine wall—but not outside the uterus—are connected to higher rates of miscarriage. This is also true if the placenta grows next to or over an existing fibroid.1

Since having fibroids is associated with more complications, it’s important to see your gynecologist to learn more about your fibroids before conceiving and then also throughout your pregnancy—especially monitoring where they are in relation to the placenta and cervix.1  Doing so could help assess the pregnancy and any potential risks. “Each person’s fibroids offer a unique situation,” Dr. Perloe stressed. “This baby is going to be around for a lifetime and you want to make sure you’re doing everything to give the baby the best life.”

ABOUT THE AUTHOR   Alicia Armeli is a Health Freelance Writer, Registered Dietitian Nutritionist, and Certified Holistic Life Coach. She has master’s degrees in English Education and Nutrition. Through her writing, she empowers readers to live optimally by building awareness surrounding issues that impact health and wellbeing. In addition to writing, she enjoys singing, traveling abroad and volunteering with her local animal shelter.

ABOUT THE DOCTOR  Mark Perloe is an infertility specialist and Medical Director at Georgia Reproductive Specialists. Dr. Perloe has extensive experience treating conditions related to infertility including menstrual disorders, uterine fibroids, endocrine and other reproductive health problems. He presently serves on the advisory board of the journal of Fertility and Sterility.


  1. Guo, X. C., & Segars, J. H., (2012). The impact and management of fibroids for fertility: an evidence-based approach. Obstetrics & Gynecology Clinics of North America, 39(4): 521-533. doi: 10.1016/j.ogc.2012.09.005.
  1. Lam, S. J., Best, S., & Kumar, S. (2014). The impact of fibroid characteristics on pregnancy outcome. American Journal of Obstetrics & Gynecology, 211(4): 395.e1-5. doi: 10.1016/j.ajog.2014.03.066.