Second‐Trimester Sonographic Comparison of the Lower Uterine Segment in Pregnant Women With and Without a Previous Cesarean Delivery

Abstract

The lower uterine segment during a second-trimester sonographic examination is significantly thinner in women with a previous cesarean delivery. Identification of the scar niche is possible in most of these women.

A study to determine scar integrity in pregnant women with previous lower segment caesarean section

“…They hypothesized that uterine dehiscence of scarred uterus may be related to altered biochemical behaviour of the scarring process. 6 No neonatal death was seen in any of the groups. No statistically significant difference was seen in neonatal outcome in both groups.…”

Timing of elective cesarean delivery at term and its impact on maternal and neonatal outcomes among Thai and other Southeast Asian pregnant women

“…At present, the mechanisms by which prior CD affect the length of pregnancy are unknown. In a literature review, women who had undergone a previous CD were reported to have a significantly thinner anterior myometrium at the lower uterine segment after delivery and in subsequent pregnancy compared with women who had delivered vaginally . Although there is no direct evidence supporting early‐onset uterine contractions in women who have had a previous CD, a mathematical model for simulating uterine contractions indicate that thinning of the myometrium has a direct impact on uterine wall stress, which could, in turn, trigger myometrial activation leading to the synchronization and coordination of uterine contractions .…”

Difference in migration of placenta according to the location and type of placenta previa

“…In one report, the mean thickness of the anterior lower segment and the mid-anterior, fundal, and posterior wall was 7.4, 9.1, 9.8, and 10.1 mm, respectively. 21 Sambaziotis et al 22 reported that the lower uterine segment during a second-trimester sonographic examination was significantly thinner in women with a previous cesarean delivery. Their results may suggest poor vascular supply at the anterior lower segment in women with previous cesarean delivery, resulting in active migration of the placenta.…”