Of all vaginal anomalies, vaginal agenesis is the most profound and may be isolated or associated with other mullerian anomalies. One example is the Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome, in which upper vaginal agenesis is typically associated with uterine hypoplasia or agenesis. Less often, this syndrome also displays abnormalities of the renal, skeletal, and auditory systems. his triad is known by the acronym MURCS, which reflects mullerian duct aplasia, renal aplasia, and �ervicothoracic �omite dysplasia (Rall, 2015).
he obstetrical significance of vaginal anomalies depends greatly on the degree of obstruction. Complete vaginal agenesis, unless corrected operatively, precludes pregnancy by vaginal intercourse. With MRKH syndrome, a functional vagina can be created, but uterine agenesis proscribes childbearing. In these women, however, ova can be retrieved for in vitro fertilization (IVF) in a surrogate mother (F riedler, 2016). U terine transplantation is currently experimental but holds future promise for these women Qohannesson, 2016).
Of other vaginal anomalies, congenital septa may form longitudinally or transversely, and each can arise from a fusion or resorption defect. Longitudinal septa divide the vagina into right and left portions. hey may be complete and extend the entire vaginal length. Partial septa usually form high in the vagina but may develop at lower levels. Septa are typically associated with other mullerian anomalies (Haddad, 1997).
During labor, a complete longitudinal vaginal septum usually does not cause dystocia because the vaginal side through which the fetus descends dilates satisfactorily. An incomplete or partially obstructed longitudinal septum, however, may interfere with descent. Occasionally, a woman with a distal longitudinal septum presents in labor. During second-stage labor, this septum usually becomes attenuated by pressure from the fetal head. After ensuring adequate analgesia, the inferior attachment of the septum is isolated, clamped, transected, and ligated. Following placenta delivery, the superior attachment can be transected while carefully avoiding urethral injury.
A transverse septum poses an obstruction of variable thickness. It may develop at any depth within the vagina, but most are in the lower third (Williams, 2014). These mayior may not be perforate, and thus obstruction or infertility is variably present. In labor, perforate strictures may be mistaken for the upper limit of the vaginal vault, and the septal opening is misidentiied as an undilated cervical os (Kumar, 2014). If encountered during labor, and ater the external os has dilated completely, the head impinges on the septum and causes it to bulge downward. If the septum does not yield, slight stretching pressure on its opening usually leads to further dilatation, but occasionally cruciate incisions are required to permit delivery (Blanton, 2003). If there is a thick transverse septum, however, cesarean delivery may be necessary.
Developmental abnormalities of the cervix include partial or complete agenesis, duplication, and longitudinal septa.
I. Hypoplasia/agenesis II. Unicornuate A. Vaginal B. Cervical A. Communicating B. Noncommunicating C. Fundal D. Tubal E. Combined C. No cavity D. No horn III. Didelphys IV. Bicornuate A. Complete B. Partial V. Septate VI. Arcuate VII. DES related A. Complete B. Partial
FIGURE 3-5 Classification of mOllerian anomalies. DES = diethylstilbestrol.(Modified with permission from American Fertility Society: