Case notes

A 30-year-old woman (gravida 1, para 1) was evaluated for secondary infertility. Her first pregnancy was delivered by cesarean section 13 months earlier, and she had an unremarkable postpartum course. Hysteroscopy, a component of the infertility workup, revealed lower uterine synechiae, which is a condition known as Asherman’s syndrome ( Figure, A ). Concomitant ultrasonography detailed a normal-appearing upper cavity with tubal patency. Hysteroscopic adhesiolysis was recommended ( Figure, B ).

A , A hysteroscopic view suggested that scar tissue obliterated the lower uterine cavity. The asterisk marks the presumed scarring. B , A sagittal ultrasound image of the upper uterine cavity indicated that all was normal. C , One month after surgery, office hysteroscopy continued to document the anterior area of scar attenuation. The double asterisk indicates demarcation; the triple asterisk identifies sharp uterine retroflexion posterior to the area of dehiscence. D , Proximal to the area of interest, the uterine cavity was otherwise normal.

Oakes. Separated from birth. Am J Obstet Gynecol 2010.

Conclusions

Ultrasound-guided cervical dilation was performed; when the hysteroscope was replaced, the appearance of the lower uterine segment was within normal limits. Banded adhesions were noted to be intact along the anterior wall, which were corrected. The tissue previously thought to represent lower uterine segment synechiae was identified instead as dehiscence of the hysterotomy scar ( Figure, A ).

A postoperative office hysteroscopy again indicated that the weakened surgical scar was distal to the normal uterine cavity ( Figure, C and D ). The patient was counseled on the risks of uterine rupture and abnormal placentation in subsequent pregnancies. She was also told that a repeat cesarean section delivery was recommended if she was to become pregnant again.

Our patient did not have Asherman’s syndrome; however, of the patients who do have the disorder, approximately 2% experience it as a result of cesarean section delivery. Other common causes include curettage after delivery, miscarriage, or abortion. The hypoestrogenic environment of the gravid uterus or other pregnancy-related changes might allow for greater damage to the uterine basalis during surgery.

Attenuation of the cesarean scar increased our patient’s risk for complications in future pregnancies. The overall incidence of uterine rupture is 1% and of abnormal placentation is 0.18%. Previous cesarean section delivery is the primary risk factor for uterine rupture; however, a history of other uterine surgeries, the presence of uterine malformations, the use of induction agents in labor, and trauma also increase risk. A history of cesarean section delivery with placenta previa in the current pregnancy is the most significant risk factor for abnormal placentation.