ORLANDO – Uterine fibroids are bad for pregnancy and neonatal outcomes, and a new study shows just how bad.
Women diagnosed with fibroids on their first obstetric ultrasound examination, for example, were significantly more likely to experience preterm labor or preterm premature rupture of the membranes (pPROM). Also, significantly more deliver before 37 weeks' gestation or via cesarean section, compared with a group of women without these noncancerous growths of the uterus.
Dr. Radwan Asaad and his colleagues compared 152 women with fibroids to another 165 matched controls in a retrospective cohort analysis conducted at Wayne State University, Detroit. They also found fibroids weren't good news for the baby either.
“Uterine fibroids complicate the pregnancy course as evidenced by a considerable impact on the obstetrical and neonatal outcomes,” Dr. Asaad said at the meeting.
In terms of the significantly different maternal numbers, women with fibroids were more likely to experience preterm labor (16.4% vs. 2.4% of controls), and pPROM (15.8% vs. 3.6%), and to deliver preterm (33.3% vs. 10.1%).
Fetal malpresentation also was significantly more likely in the fibroid group (22% vs. 6% in controls). Cesarean delivery occurred in 54.3% of the fibroid group vs. 28.0% of the control group, another significant difference.
Gestational age at delivery was significantly less when the mother had fibroids (mean 35.3 weeks) vs. without (38.6 weeks).
Children born to women in the fibroid group had a mean birth weight of 2,634 g, compared with 3,181 g for those born to control group women. Apgar scores at 1 minute were a mean 6.7 vs. 7.8 in the control group and at 5 minutes were a mean 7.9 vs. 8.8.
Pregnancy loss was higher in the fibroid group during the first trimester (7.9% vs. 3.6% in controls) and during the second trimester (5.9% vs. 1.2%), but these differences were not statistically significant to the P less than .001 level. A trend toward more arrested dilation in the fibroid group likewise did not reach significance.
“Uterine myomas are the most common pelvic tumor in reproductive-age women,” said Dr. Asaad, a laparoscopic and minimally invasive surgeon in the department of obstetrics and gynecology at Hutzel Women's Hospital and Wayne State University/Detroit Medical Center. Prevalence in published studies varies from 2% to 11%, depending on the trimester in which they are measured and the size threshold chosen by researchers.
A meeting attendee asked for information on the size and anatomic location of the fibroids. Dr. Asaad replied that he was only able to categorize women dichotomously as yes/no for presence of fibroids in this retrospective study.
Dr. Asaad and his associates reviewed all department ultrasounds from 1998 to 2006 at their tertiary care center. Women with complete records in the fibroid group were matched to controls for age, gravidity, parity, and year of delivery.
He said he had no relevant financial disclosures.