Jim G. Thornton, Lynne Fogg, Sonia Asif, Lukasz Polanski, Pooja Jassal, Nick J. Raine-Fenning, Michelle Parris-Larkin, Matthew Prior, Jane Chandler, Alison Richardson
To assess the effect on reproductive outcome of congenital uterine anomalies in subfertile women in women undergoing assisted reproduction.
All women referred with subfertility between May 2009 and November 2015 who underwent assisted reproduction. As part of their initial assessment each woman was assessed by pelvic three-dimensional ultrasonography. The uterine morphology was classified using the modified American Fertility Society (AFS) classification of congenital anomalies. If the external contour of the uterus was uniformly convex or with an indentation less than 10 mm, but involving an internal indentation, it was defined as arcuate or a uterine septum. Arcuate was defined as a concave fundal indentation with central point of indentation at an obtuse angle. A subseptate uterus was defined as the presence of a septum, not extending to the cervix, with a central point of septum at an acute angle. If the septum extended to the internal os, the uterus was defined as septate. Reproductive outcomes were compared between those with a normal uterus and uterine anomalies.
A total of 2375 women were included in the study of whom 1943 (81.8%) had normal uterus and 432 (18.2%) had uterine anomalies. The most common anomalies were arcuate (N=387, 16.3%), and subseptate (N=16, 0.7%). Rates of live birth were similar in the two study groups (35% and 37%, respectively, p = 0.47). The clinical pregnancy rate, mode of delivery and sex of the newborn also did not differ. Preterm birth before 37 weeks’ gestation was more common in women with uterine anomalies than controls, (22% versus 14%, respectively p = 0.03). Subgroup analysis by type of anomaly showed no difference in live birth and clinical pregnancy rates for women with arcuate uteri but worse outcomes for women with other major anomalies (p = 0.04 and 0.048 respectively).
Congenital uterine anomalies as a whole, when defined using the modified AFS classification, do not affect clinical pregnancy or live birth rates in women after assisted reproduction but do increase rates of preterm birth. Abnormalities more severe than arcuate significantly worsen all pregnancy outcomes.