Transabdominal Cerclage: Who, When, How

Transabdominal cerclage (TAC) was devised over 60 years ago with several controlled studies and a randomized controlled trial (RCT) evaluating its safety and efficacy. TAC has biologic rationales for being more effective than transvaginal cerclage (TVC) given its sterile placement higher in the cervix at the level of the internal os. TAC decreases recurrent preterm birth (PTB) in patients with a prior spontaneous PTB (SPTB) < 28 weeks despite a transvaginal (TV) history-indicated cerclage (HIC) or ultrasound-indicated cerclage (UIC), as supported by level 1 data, and should be offered to these patients. The supportive data are on open TAC (OTAC) or laparoscopic TAC (LTAC), done pre-pregnancy or in-pregnancy in the 1st trimester in patients with a normal (not short or dilated) cervix. The data on other indications are too limited to recommend TAC for other clinical scenarios. Pregnancy outcomes are excellent with both pre-pregnancy and in-pregnancy TAC. For both LTAC and OTAC, there is some evidence that pre-pregnancy timing is associated with better pregnancy outcomes and lower complications than in-pregnancy OTAC. After meticulous pre-operative planning ensuring proper TAC indication and an experienced surgeon, the LTAC, possibly robotically, technique should be preferred. LTAC has been associated with the best outcomes when performed pre-pregnancy. This outpatient procedure does not usually require other peri-operative interventions and has a very quick recovery period. Complications of TAC are uncommon (<5%), and lower with LTAC compared to OTAC. Fertility rates after pre-pregnancy TAC are excellent and compare well to the general population or appropriate controls. During pregnancy, patients with TAC in place should be started on vaginal progesterone at 16 weeks. In cases of early pregnancy loss, an MVA or D&E can usually be feasible through the TAC. Planned CD at 38 weeks is usually recommended with TAC left in situ. Transvaginal removal of a TAC is feasible, especially when the suture has been placed using a technique that anchors the knot vaginally, and may be considered in patients who desire vaginal birth and have completed childbearing. TAC can usually be safely left in place after pregnancy, helping prevent PTB in multiple future pregnancies.