Scientists Dispute Link Between Uterine Fibroid and Miscarriage Threat

A recent study, led by scientists from Vanderbilt University has disputed the conventional reasoning that uterine fibroids are the cause of miscarriages in women.

Fibroids are abnormal growths that develop in or on a woman’s uterus. Sometimes these tumours become quite large and cause severe abdominal pain and heavy periods. In other cases, they cause no signs or symptoms at all. The growths are typically benign, or noncancerous.

Explaining the effects of fibroids on women, Professor of obstetrics and gynaecology, Katherine Hartmann, said women with fibroids are not at increased risk of miscarriage, as women with fibroids had identical risk of miscarriage as women without fibroids when taking into account other risks for pregnancy loss.

Fibroids are common benign uterine masses that can distort the external and internal contour of the uterus. Changes in uterine architecture and other local effects of fibroids have been implicated in prior research as a risk factor for miscarriage, said Hartmann.

According to prof. Hartmann: “This is great news for women. Our results challenge the existing paradigm and have potential to reduce unnecessary surgical intervention”.

The study titled: “Prospective Cohort Study of Uterine Fibroids and Miscarriage Risk,” included women from eight urban and suburban communities in three states to achieve a racially diverse cohort of women planning pregnancies or in the early weeks of pregnancy. Each woman in the Right from the Start study had a standardized ultrasound for fibroids to determine presence, number, size and location in the uterus.

Investigators from Vanderbilt, University of North Carolina-Chapel Hill and the National Institutes of Health (NIH) National Institute of Environmental Health Sciences, accrued the largest prospective cohort to date to investigate the association of fibroids with miscarriage, said Hartmann, the study’s principal investigator.

Of the more than 5,500 women enrolled, ultrasound detected uterine fibroids in 11 percent, while 89 percent of the study participants did not have fibroids. The chance for miscarriage in both groups was 11 percent.

The principal investigator said, the key message is that fibroids don’t seem to be linked to miscarriage. She also admitted the initial goal of the study was to understand which fibroids confer the highest risk of miscarriage in order to determine who might benefit most from surgery to remove the fibroids before a future pregnancy.

The authors explained their analysis likely reached different conclusions than other studies for several reasons: few earlier studies conducted ultrasounds for all participants to document fibroid status; no prior prospective cohorts took into account the influence of age and race. Age and African-American race/ethnicity are both associated with having miscarriages; and prior conclusions did not untangle these confounding factors, and fibroids were incorrectly blamed.

Hartmann said when all factors are taken into account, the surprising results of the study should give both women and care providers’ reassurance.

The journal medicine in tropics showed that more than 1 million miscarriages occur in Nigeria each year.

Hartmann concluded that loss is remarkably common, but we know very little about the causes. When something bad happens in a pregnancy the first thing women look at is themselves, asking why it happened and what they could have done differently.” Now women with fibroids have one less thing to worry about.” Hartmann added.


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