PART 1: Advising your patients Uterine fibroids: Childbearing, cancer, and hormone effects
Women who have uterine fibroids are often fearful about what the diagnosis means. Discussing the evidence with them provides reassurance for most.
IN THIS ARTICLE
- preterm delivery
- premature rupture of membranes
- fetal growth restriction
- placenta previa
- placental abruption
- postpartum hemorrhage
- retained placenta.
Only cesarean section was more common among women with fibroids (23% vs 12%).
The second study reviewed 15,104 pregnancies and compared 401 women found to have myomas and the remaining women who did not.16 Although the presence of myoma did not increase the risk of premature rupture of membranes, operative vaginal delivery, chorioamnionitis, or endomyometritis, there was some increased risk of pre-term delivery (19.2% vs 12.7%), placenta previa (3.5% vs 1.8%), and post-partum hemorrhage (8.3% vs 2.9%). Cesarean section was, again, more common (49.1% vs 21.4%).
Do myomas injure the fetus?
Fetal injury as a consequence of fibroids has been reported very infrequently. A review of the literature from 1980 to 2005 revealed only four cases—one each of:
- fetal head anomalies with fetal growth restriction
- postural deformity
- limb reduction
- fetal head deformation with torticollis.17-19
CASE 2 RESOLVED Should Mrs. H. have a myomectomy?
Probably not. Abdominal and laparoscopic myomectomy involve substantial operative and anesthetic risks, including infection, postoperative adhesions, a very small risk of uterine rupture during pregnancy, and increased likelihood of cesarean section. Costs are also substantial, involving not only the expense of surgery, but also patient discomfort and time for recovery. Therefore, until it is proved that intramural myomas decrease fertility and myomectomy increases fertility, surgery should be undertaken with caution. As far as the effects of myoma on pregnancy are concerned, no data are available by which to compare pregnancy outcomes following myomectomy with pregnancy outcomes in women whose myomas are untreated. Randomized studies are needed to clarify these important issues.
CASES 3 & 4 The effects of oral contraceptives and hormone replacement therapy
Mrs. J. is a 32-year-old G0P0 woman who has a 5-cm fundal myoma. She is sexually active and wants to use an oral contraceptive (OC). She has heard from friends, however, that taking an OC makes fibroids grow, and she asks for your advice.
The same day, you see Mrs. K., a 54-year-old, recently menopausal woman. She complains of severe hot flashes and night sweats that disturb her sleep. She has had asymptomatic uterine fibroids for about 10 years and, although she would like to take menopausal hormone therapy, she is worried that the medication will make the fibroids larger.
How do you advise these two women?
OCs. OCs do not appear to influence the growth of fibroids. One study found a slightly increased risk of fibroids, another study found no increased risk, and a third found a decreased risk.18,19 These studies are retrospective, however, and may be marked by selection bias.
Postmenopausal hormone replacement therapy. Postmenopausal hormone therapy does not ordinarily cause fibroid growth. After 3 years, only three of 34 (8%) post-menopausal women who had fibroids and were treated with 0.625 mg of conjugated equine estrogen (CEE) and 5 mg of medroxyprogesterone acetate (MPA) a day had any increase in the size of fibroids.20 If any increase in the size of the uterus is noted, it is likely related to progestins.
A study found that 23% of women taking oral estrogen plus 2.5 mg of MPA a day for 1 year had a slight increase in the size of fibroids, whereas 50% of women taking 5 mg of MPA had an increase in size (mean increase in diameter, 3.2 cm).21 Transdermal estrogen plus oral MPA was shown, after 1 year, to cause, on average, a 0.5-cm increase in the diameter of fibroids; oral estrogen and MPA caused no increase in size.22
CASES RESOLVED Rx: Reassurance
Advise Mrs. J. that taking an OC is unlikely to make her fibroids grow larger.
Mrs. K., who is older, can seek relief from postmenopausal symptoms by taking hormone therapy without fear of her fibroids being stimulated to grow.
