Introduction: Two cases of unilateral adnexal absence and ectopic ovarian hypoplasia with fallopian tube absence are herein reported, along with a systematic review of the literature and a discussion on the main factors causing these malformations.
Evidence acquisition: The MEDLINE database was searched for English language medical reports published between 1973 and 2014. The key words used were "ovarian agenesis", "ovarian hypoplasia", "undescended ovary" and "fallopian tube abnormalities".
Evidence synthesis: Five studies were included on unilateral ovarian maldescent without uterine anomalies, along with 23 reports of unilateral absence of one ovary in presence or absence of the fallopian tube.
Conclusions: Even though of Müllerian duct anomalies are relatively common, congenital defects or absence of an ovary is quite rare. It would be interesting to investigate and to correlate the presence of such rare anomalies with the percentage of pregnancies. Therefore, further evaluation and larger studies are needed.