Birth outcomes and pregnancy complications of women with uterine leiomyoma—a population-based case-control study

Objective Uterine leiomyoma is not a rare pathological condition in pregnant women; thus the aim of the study was to evaluate the recent progress in the treatment of these pregnant women on the basis of the association of leiomyoma in pregnancy (LP) with pregnancy complications and birth outcomes including structural birth defects, i.e. congenital abnormalities (CA) in the offspring. Design Cases with CA and matched controls without CA in the population-based Hungarian Case-Control Surveillance System of Congenital Abnormalities (HCC SCA) were evaluated. Only women with prospectively and medically recorded LP in prenatal maternity logbook and medically recorded birth outcomes (gestational age, birth weight, CA) were included to the study. Setting the HCCSCA, 1980-1996 contained 22,843 cases with CA and 38,151 matched controls without CA. Population Hungarian pregnant women and their informative offspring: live births, stillbirths and prenatally diagnosed malformed fetuses. Methods Comparison of birth outcomes of cases with matched controls and pregnancy complications of pregnant women with or without LP. Main outcome measures Pregnancy complications, mean gestational age at delivery and birth weight, rate of preterm birth, low birthweight, CA. Results A total of 34 (0.15%) cases had mothers with LP compared to 71 (0.19%) controls. There was a higher incidence of threatened abortion, placental disorders, mainly abruption placentae and anaemia in mothers with LP. There was no significantly higher rate of preterm birth in the newborns of women with LP but their mean birth weight was higher and it associated with a higher rate of large birthweight newborns. A higher risk of total CA was not found in cases born to mothers with LP (adjusted OR with 95% CI = 0.7, 0.5-1.1), the specified groups of CAs were also assessed versus controls, but a higher occurrence of women with LP was not revealed in any CA group. Conclusions Women with LP have a higher risk of threatened abortion, placental disorders and anaemia, but a higher rate of adverse birth outcomes including CAs was not found in their offspring.