Uterine Fibroids and Breastfeeding

CQ #153 – July 15, 2019

by Anne Eglash MD, IBCLC, FABM

#LACTFACT

Uterine fibroids are more likely to regress postpartum if the mother breastfeeds.

The association between childbirth, breastfeeding, and uterine fibroids: an observational study

Nature

What are uterine fibroids and how does breastfeeding affect them?

Uterine fibroids are non-cancerous growths that occur during childbearing years. According to the authors of this week’s CQW, the prevalence of uterine fibroids during pregnancy is not clear, estimated at 0.1-10%, partially because they are harder to identify during pregnancy. They can cause health problems, such as infertility and risk of pregnancy complications. Sometimes they can twist on their own blood supply, causing inflammation and pain.

Uterine fibroids vary as to whether they grow during pregnancy and if they do grow, they tend to grow in the first trimester. Most fibroids will not grow during the second and third trimesters. Many fibroids become smaller after childbirth and several studies have shown that the more pregnancies a woman has, the lower the risk of uterine fibroids.

In this study done at an Italian medical institution, the authors investigated the effect of childbirth and breastfeeding on uterine fibroids.

This is an observational study that identified 213 pregnant women with a pre-pregnancy diagnosis of a uterine fibroid > 1 cm in size. After excluding several individuals due to multiples, miscarriage, and other issues, 157 were in the final cohort. Approximately 28% underwent a cesarean birth, and 9.5% had a preterm birth. At the 6-month follow-up, 67.5% were still breastfeeding.

Which statements do you believe are accurate regarding the relationship between uterine fibroids and breastfeeding? Choose 1 or more:

The uterine fibroids of the non-breastfeeding mothers grew postpartum, but the fibroids of the breastfeeding mothers didn’t grow.
Among all mothers, approximately 37% of the fibroids disappeared postpartum, while approximately 17% of fibroids were larger postpartum.
Women who breastfed were more likely to have stability or regression of their fibroids at 6 mo postpartum, as long as the fibroids were less than 32mm.
Pre-pregnancy fibroids over 32mm in size were not more likely to regress in size due to breastfeeding.
Women who delivered via cesarean had more postpartum regression of fibroids.

See the Answer

Correct Answers: All except A and E

The association between childbirth, breastfeeding, and uterine fibroids: an observational study

Nature

Giovanni Delli Carpini, Stefano Morini, Maria Papiccio, Matteo Serri, Valentina Damiani, Camilla Grelloni, Nicolò Clemente & Andrea Ciavattini

Abstract

The aim of this study was to investigate the effect of childbirth and breastfeeding on uterine fibroids and to identify the factors associated with size variations. This was a monocenter observational study carried on women with a sonographic diagnosis of uterine fibroids from January 2007 to December 2016, with no indication for immediate treatment, and who became pregnant within one year from diagnosis. All patients were re-evaluated six months after delivery. Fibroid diameters were compared between pre-pregnancy period, first, second, third trimester and post-delivery. The rate of “regressed” (growth of diameter <−40%), “unchanged” (growth of diameter between −40% and +40%) or “increased” (growth of diameter >+40%) fibroids at the post-delivery evaluation with respect to the pre-pregnancy state was calculated. One-hundred fifty-seven women were included in the final analysis. At the post-delivery ultrasound, a significant reduction of the fibroid diameter with respect to all previous examinations was observed, and there was no evidence of 67 (37.2%) fibroids. Ongoing breastfeeding was positively associated with an “unchanged” or “regressed” fibroid diameter (adOR 3.23, 95%CI: 1.35–7.70, p < 0.01). Smaller pre-gravidic fibroids were more likely to return to prepregnancy dimensions or to regress, with a cut-off of 32 mm for lactating women and of 26 mm for nonlactating women. In conclusion, fibroids seem to return to pre-pregnancy dimensions or to regress in the post-partum period. This process may be sustained by uterine involution and hormonal variations, with an additional role of breastfeeding.

IABLE Comment by Anne Eglash MD, IBCLC, FABM

The authors discuss several possible reasons why fibroids may be smaller postpartum than pre-pregnancy. The short term decreased blood flow to the uterus when the placenta separates, to prevent excessive blood loss, may cause decreased blood flow to the fibroid, resulting in cell death. Uterine remodeling after birth may also cause cell death of the fibroid tissues. Breastfeeding suppresses the ovarian hormones estrogen and progesterone, preventing stimulation of fibroid growth.

Type of birth, either vaginal or cesarean, had no effect on fibroid growth or regression postpartum.

Gosego Ivy Mmeanyana

October 15, 2019 at 9:45 AM

I am 33yrs, and was diagnosed with fibroids in my second pregnancy (2 which were around 70mm), during my third pregnancy the grew to around 90mm and 95mm but their position did not affect my delivery plan and i delivered naturally in both pregnancies. I am currently 8 months postpartum and still breast feeding – they have reduced to around 24mm and 30mm and the doctor cleared me for possible operation.
My worry is that i now have bleeding every now and then ( I normally don’t get my periods while breast feeding – for all my 3 kids). The bleeding is spotting sometimes and sometimes seem like a period but happens maybe once/twice a week and does not happen for the whole day.
1. what could be causing this? – my gynae just told me that its the fibroids misbehaving and that i should continue with S/activity and use condoms.
2.How can i stop it?
3. is it likely to stop when i stop breast feeding?

Esther

October 16, 2019 at 5:33 AM

I had fibroid before I got pregnant and I deliver through cesarean , my baby will be 10 months this October but I feel abdominal pain at time and it last for days , so I don’t know if my fibroid is shrinking or not.

Rana

November 21, 2019 at 12:25 PM

I’m in my late 30s and have a 10 month old that was delivered vaginally and found out that I have fibroids due to spotting and irrigular heavy bleeding.I had c-section with my other child 8 years ago.The Doctor says it’s small but watch the period next month but I got period twice a month now.please help I’m worried.I also have a blood clot that I got during this pregnancy and still on blood thinners.how do I work with both problems.

Angel

November 25, 2019 at 12:48 PM

Am a breastfeeding mother, my baby is just Four months. I want to know if drinking the fibroid tea will affect my child.
1. Can a breastfeeding mother drink fibroid tea.
2. What is the side effect on the baby.