Pregnancy and Fibroids: What you need to know from the expert

Uterine fibroids are considered the most common gynecological tumors, which according to some studies occur in 70-80% of women during the reproductive age.

Their size varies and can be from a few millimeters to several centimeters, even occupying the entire abdomen. The main causes of fibroids are heredity combined with increased estrogen levels.

In many cases, fibroids are asymptomatic and their diagnosis requires clinical examination or imaging. However, in other cases it has been observed that fibroids can cause significant morbidity such as menstrual abnormalities (eg, heavy, irregular and prolonged uterine bleeding), iron deficiency anemia, pelvic pressure/pain and fertility problems.

The effects of fibroids depend on their size, location and speed of growth. Regarding the effect of fibroids on pregnancy, there are conflicting opinions. 

In most of the studies that have been carried out, the ultrasound examination during pregnancy showed that the size of the fibroids remained stable, while in some cases even a reduction in their size was observed.

Uterine fibroids and complications in pregnancy

However, about 10% to 30% of women with uterine fibroids develop complications during pregnancy. Depending on the location of a fibroid there is a risk of miscarriage, premature delivery, premature detachment, premature rupture of the membranes or intrauterine growth retardation. Fibroids located in the lower part of the uterus, increase the possibility of dysproportion at delivery, caesarean section and postpartum bleeding.

It has also been observed that spontaneous abortion rates are significantly increased in pregnant women with fibroids compared to those without (14% vs. 7,6%, respectively). The mechanism by which fibroids cause spontaneous abortions is unclear.

The phenomenon of bleeding in the early stages of pregnancy may be due to the location of the fibroid. The incidence of bleeding in the early stages of pregnancy is significantly more frequent in pregnancies where the placenta implants on or near a fibroid compared to pregnancies in which there is no contact between the placenta and the fibroid.

Regarding preterm delivery and premature rupture of membranes, pregnant women with fibroids were significantly more likely to deliver preterm than women without fibroids (16,1% vs. 8,7% and 16% vs. 10,8%, respectively. ). In cases of multiple fibroids contacting the placenta there appears to be an independent risk factor for preterm delivery. In contrast, fibroids do not appear to be a risk factor for premature rupture of membranes.

Fetal development does not appear to be affected by the presence of uterine fibroids. Although pooled data and a population-based study showed that pregnant women with fibroids are at slightly increased risk of giving birth to an infant with intrauterine growth retardation, the results were not adjusted for maternal age or gestational age.

Additionally, it is worth noting that some fetal abnormalities have been reported in women with large submucosal fibroids, such as dolichocephaly (lateral compression of the fetal skull), torticollis (abnormal twisting of the neck), and limb defects.

Pregnancy pain and fibroids

Finally, pain is the most common complication of fibroids during pregnancy. Symptoms can usually be managed with conservative treatment (rest, hydration, and analgesics), although in rare cases definitive surgical excision may be required.

Thank you dr. Stefano Khandaka, obstetrician, endoscopic surgeon, gynecology graduate of the School of Medicine of the University of Athens with training in England and the United States in obstetrics, gynecology and laparoendoscopic / robotic surgery, member of the Scientific Council of the MITERA hospital of the HYGEIA Group. http://www.drchandakas.gr/