Double layer vs single layer uterine closure in cesarean results in stronger uterine scar and increases chances of vaginal birth in future pregnancies.

Transabdominaluterine scar measurement at 36-38 weeks.

Double layer closure of uterus during previous cesarean section results in thicker third-trimester lower uterine segment and decreases rate of uterine rupture by 3 to 5fold during trial of labor after cesarean (TOLAC) and vaginal birth after cesarean reports results of multicenter prospective cohort study published in July issue of Journal obstetrics and gynecology.

In U.S.A, about 1.3 million babies are delivered by Cesarean every year, which roughly equals to every 1 in every 3 children born in US (33%). Decrease in vaginal births after cesarean and TOLAC has significantly contributed to the rising C-section rates. Significant maternal and neonatal mortality and morbidity because of uterine rupture has increased the rate of elective repeat C-section (ERC).

Lower uterine segment thickness (LUST) as measured by ultrasound is routinely used in clinical practice to estimate the risk of uterine rupture during TOLAC.  A value of <2.0 mm measured between 35 and 38 weeks is significantly associated with greater incidence of uterine rupture or scar dehiscence compared with a measurement >2.0 mm.

The researchers performed a secondary analysis of study conducted at 4 hospitals over a period of 5 years. Out of 1856 women originally recruited, records about uterine closure in previous C-section were available for 1613 patients.

Each of the study participant received transvaginal and transabdominal sonography for measuring LUST between 34 weeks to 38 weeks and 6 days of pregnancy.  Each measurement was confirmed at least 3 times.

Thirty-one percent (495) of patients had undergone a single layer closure, whereas 69% (1118) had undergone a double layer closure at the time of previous C-section.

After adjustment of confounding factors, it was observed that patients with double layer uterine closure had 32% less odds of third-trimester LUST <2.0 mm in the next pregnancy (P<.01).

Type of catgut (Chromic vs synthetic) did not have any effect on thickness of lower uterine segment in next pregnancy. Other factors that resulted in LUST < 2 mm were interdelivery interval <18 months; a body mass index >30 kg/m2; and an elective or planned cesarean delivery.

If previous cesarean was performed in labor than it resulted in thicker lower uterine segment as compared to cesarean performed electively. So, double layer closure becomes all the more important in elective cesarean sections.

Patients were followed up till delivery and it was seen that patients with double layer closure were slightly more likely to undergo TOLAC or vaginal birth. Double layer closure was also significantly less likely to be associated with uterine scar defect and dehiscence.

The authors concluded that, “the current study supports the use of double-layer suture of the uterus at cesarean, especially when it is performed before labor, to optimize uterine scar healing. This technique could lead to a reduction of uterine scar defects during a TOLAC.”

Full text can be accessed here.

Source: Single versus double-layer uterine closure at cesarean: impact on lower uterine segment thickness at next pregnancy

Vachon-Marceau, Chantale et al.

American Journal of Obstetrics & Gynecology , Volume 217 , Issue 1 , 65.e1 - 65.e5