Background: Whether implantation occurs after in vitro fertilization (IVF) depends on the embryo, uterine receptivity or a combination of both. The prevalence of minor intrauterine abnormalities identified at hysteroscopy in cases with a normal transvaginal sonography (TVS) has been recorded to be as high as 20-40%. Diagnosing and treating such pathology prior to initiating IVF/intra-cytoplasmic sperm injection (ICSI), has been widely advocated without high-quality evidence of a beneficial effect. The objective of the current study was to assess, by screening office hysteroscopy, the prevalence of unsuspected intrauterine abnormalities in an asymptomatic population of IVF patients, in whom TVS had not revealed any pathology.
Methods: The prevalence of unsuspected intrauterine abnormalities in patients allocated for a randomized controlled trial was prospectively assessed at two tertiary infertility care units: Academic Hospital at the Dutch-speaking Brussels Free University and University Medical Center Utrecht. A total of 678 unselected, asymptomatic, infertile women with a regular indication for a first IVF/ICSI treatment underwent office hysteroscopy. Only asymptomatic patients, aged < or = 42 years, with a normal TVS and no previous hysteroscopy were included. The presence of predefined intrauterine abnormalities was recorded and described in a standardized manner.
Results: Endometrial polyps were identified in 41 (6%) women and submucous myomas in 6 women (1%). Some women were also diagnosed with intrauterine adhesions (2%) or septa (2%). The overall prevalence of any predefined intrauterine abnormality in this IVF/ICSI population was 11%.
Conclusions: The observed prevalence of unsuspected intrauterine abnormalities in asymptomatic patients indicated for their first IVF/ICSI treatment appeared to be clearly lower than previously reported (11 versus 20-45%). This may have implications for the significance of these abnormalities regarding prospects in IVF/ICSI treatment cycles.