Several studies have reported very good concordance between 3-D TVS and MR imaging of muUerian anomalies (Deutch, 2008; Graupera, 2015). MR imaging is often preferred for complex anatomy, especially cases for which corrective surgery is planned. MR imaging provides clear delineation of both the internal and external uterine anatomy and has a reported accuracy of up to 100 percent for mullerian anomaly evaluation (Bermejo, 20 I0; Pellerito, 1992). In addition, com plex anomalies and commonly associatcd secondary diagnoses such as renal or skeletal anomalies can be concurrendy evaluated. Precautions wirh MR imaging in pregnancy are discussed in Chapter 46 (p. 910).
In some women undergoing an inferrility evaluation. hysteroscopy and laparoscopy may be selected co assess for mullerian anomalies; screen for endomctriosis, which is often coexistent; and exclude other tubal or uterine cavity pathologies (Puscheck, 2008; Saravelo" 2008). In pregnancy, these approaches are rarely used co diagnose mullerian anomalies. and hysteroscopy is contraindicated.
Wirh this abnormality, the underdeveloped or rudimentary horn may be absent. If present, it may or may nor communicatewith the domin�nr horn �nd may or may not contain an endomerrium-Iined cavity (see Fig. 3-5). General population estimates cite an incidence of I in 4000 women (Reichman, 2009). This anomaly may be detected during ferrility evaluation by HSG. Bur as nored, noncommunicating or noncavirary rudimentary horns may not ill with dye. If this anomaly is suspected. 3-D sonography increases diagnostic accuracy, but again MR imaging may be preferred. Importantly, 40 percent of afected women will have renal anomalies (Fedele, 1996).
This mullerian anomaly carries signiicant obstetrical risks, including first-and second-trimester miscarriage. malpresentation, fetal-growth restricrion. fetal demise. prematurely ruprured membranes, and preterm delivery (Chan, 2011 a; Hua, 2011; Reichman, 2009). Abnormal uterine blood Row, cervicl incompetence, and diminished cavity size and muscle mass of the hemiurerus are postulated ro underlie these risks (Donderwinkel, 1992).
Rudimentary horns also increase the risk for an ectopic pregnancy within rhe remnant, which may be disastrous. This risk includes noncommunicating cavitary rudiments, for which transperironeal sperm migration permirs ovum fertilization and pregnancy (Nahum, 2004). In a report of 70 sllch pregnancies, Rolen and associares (1966) found that the rudimentary uterine horn ruptured prior to 20 weeks in most. Nahum (2002) reviewed the literature from 1900 to 1999 and identiied 588 rudimentary horn pregnancies. Half had uterine rupture, and 80 percent did so before the third rrimesrer. Of the rotal 588, the neonatal survival race was only 6 percent.
Imaging allows an earlier diagnOSiS of rudimentary horn pregnancy so that it can be treated either medically with methotrexare or surgically before rupture (Dove, 2017; Edelman, 2003; Khati, 2012; Worley, 2008). lthough not emphasized in Figure 3-5, the anachmem sire between rhe rudimentary horn at times can be broad and vascular.