Size of uterine leiomyoma is a predictor for massive haemorrhage during caesarean delivery.

BACKGROUND: Uterine leiomyoma is a common benign tumour, and a risk factor for various complications during pregnancy and peripartum period. Peripartum haemorrhage is the most critical complication that can cause maternal death. Although the relationship of leiomyoma and peripartum haemorrhage has been indicated, little is known about the characteristics of leiomyoma as predictors for massive haemorrhage in caesarean delivery.

OBJECTIVE: We examined whether characteristics of leiomyoma and pregnant patients could predict massive haemorrhage in women undergoing caesarean delivery.

STUDY DESIGN: This is a single-institution, retrospective cohort study. We reviewed singleton caesarean deliveries between January 2005 and December 2011. We excluded women with the following risk factors for massive haemorrhage: abnormality of placental position, abruptio placentae, haemorrhagic diseases, hydramnios, and labour arrest after induction. Myomectomy was not performed during delivery. Multivariate logistic regression analysis was performed to identify predictors of massive intraoperative haemorrhage (≥1000 ml). The following predictors were evaluated: maternal age, body mass index, parity, gestational week, birth weight, number of leiomyomas, and volume of the largest leiomyoma. Detailed characteristics of leiomyomas were evaluated using sonography or magnetic resonance imaging.

RESULTS: Seven hundred and fifty-nine women were included; 55 women (7.25%) had leiomyoma. Thirty-eight women with leiomyoma underwent magnetic resonance imaging scan. The median intraoperative haemorrhage was 939 ml (395-5296 ml) in women with leiomyoma and 689 ml (129-3060 ml) in women without. Multivariate analysis revealed that a largest leiomyoma ≥175 cm3 (odds ratio 6.4 [95% confidence interval: 1.5-27], P = 0.007), birth weight of ≥2500 g (2.3 [1.53.6], P < 0.001), and primipara (1.5 [1.1-2.1], P = 0.025) were significant predictors of massive intraoperative haemorrhage.

CONCLUSIONS: The presence of a leiomyoma of ≥175 cm3 , birth weight of ≥2500 g, and primipara were found to be predictors for massive intraoperative haemorrhage during caesarean delivery. A leiomyoma ≥175 cm3 which is equivalent volume to a 7 cm diameter sphere can be diagnosed in the first trimester using sonography. In cases of cesarean delivery with these predictors, preparation for massive haemorrhage, including storage of autologous blood, may be considered.