Growth trend of small uterine fibroids and human chorionic gonadotropin serum levels in early pregnancy An observational study

Capsule:
Small fibroids seem to grow rapidly in the first weeks of pregnancy, with a nonlinear trend, in relation to the similar growth of human chorionic gonadotropin in the same period.

Authors:
Andrea Ciavattini, M.D., Giovanni Delli Carpini, M.D., Nicolò Clemente, M.D., Lorenzo Moriconi, M.D., Chiara Gentili, M.D., Jacopo Di Giuseppe, M.D.

Volume 105, Issue 5, Pages 1255-1260

Abstract:

Objective:
To analyze the growth trend of small uterine fibroids during early pregnancy, evaluating the potential factors involved, with particular interest in hCG levels.

Design:
Observational study.

Setting:
Tertiary care university hospital.

Patient(s):
Women who had an ultrasound diagnosis of small myomas (diameter, ≥10 mm and ≤50 mm) from January 2007 to December 2013, and who subsequently became pregnant within 1 year.

Intervention(s):
None.

Main Outcome Measure(s):
Three additional ultrasound examinations were performed during early pregnancy (7–8, 10–13, and 20–22 complete gestational weeks, respectively) and the modifications in diameter and volume of each uterine fibroid were recorded. A serial evaluation of hCG serum levels from 5–12 weeks was performed.

Result(s):
From the 109 women who fulfilled the study inclusion/exclusion criteria, a significant increase emerged, both for volume and diameter of the detected fibroids. Specifically, a median growth rate (GR) of 122% was observed during the interval of the first to the second ultrasound, whereas a median GR of 108% was detected during the interval between the second and the third ultrasound, and a median GR of 25% between the third and the fourth ultrasound. A significant positive correlation between hCG levels and diameter (R = 0.69) of myomas between 5 and 12 weeks emerged.

Conclusion(s):
A remarkable nonlinear growth of small fibroids during initial pregnancy was observed, with a faster rate in the first trimester and a slow down by midpregnancy. Those changes seem to be related to the similar increase of hCG levels until 12 weeks.

  • Amanda N. Kallen

    Very interesting findings. Do the authors have any speculation as to why smaller fibroids might exhibit more growth? I’m thinking diminished blood flow / diminished exposure to the effects of hCG if your hypothesis re: effects of hCG on fibroid growth is true. It would be interesting to evaluate whether you see even more marked rapid-growth effects in situations where hCG is known to rise even more rapidly (molar pregnancy / twins). Thanks again for an interesting study!

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