Table 3.
Perioperative and sonographic outcomes.
| Variables | Single‐layer closure (n = 1144) | Double‐layer closure (n = 1148) | Outcome measure | Adjusted effect estimate (95% CI) a | P |
|---|---|---|---|---|---|
| Perioperative outcomes | |||||
| Operative time, minutes from incision to closure | 38.9 (11.7) | 42.8 (11.2) | Mean difference | 3.9 (3.0 to 4.9) | <0.001 |
| Blood loss (mL), geometric mean (95% CI) | 405 (392 to 420) | 415 (400 to 430) | Geometric mean ratio | 1.02 (0.97 to 1.07) | 0.384 |
| Need for additional haemostatic sutures | 462 (40.5%) | 462 (40.4%) |
Relative risk Risk difference |
1.00 (0.90 to 1.10) −0.00 (−0.04 to 0.04) |
0.948 0.981 |
| Number of additional haemostatic sutures needed b | 1 (1–2) | 1 (1–2) | Median difference | 0.0 (−0.1 to 0.1) | 1.0 |
| Hospital stay, days | 3.0 (2.0–4.0) | 3.0 (2.0–3.0) | Median difference | 0.0 (−0.1 to 0.1) | 1.0 |
| Complication rate c | 118 (10.3%) | 104 (9.1%) |
Relative risk Risk difference |
0.88 (0.69 to 1.13) −0.01 (−0.04 to 0.01) |
0.320 0.293 |
| Readmission rate | 13/1013 (1.3%) | 13/1015 (1.3%) |
Relative risk Risk difference |
1.00 (0.47 to 2.14) 0.00 (−0.01 to 0.01) |
0.996 0.973 |
| Sonographic outcomes, d n | 993 (86.8%) | 968 (84.3%) | — | — | — |
| Niche prevalence | 684 (68.9%) | 712 (73.6%) |
Relative risk Risk difference |
1.06 (1.01 to 1.13) 0.05 (0.01 to 0.09) |
0.033 0.027 |
| RMT, mm | 6.4 (3.3) | 6.7 (3.4) | Mean difference | 0.3 (−0.1 to 0.6) | 0.108 |
| RMT/AMT ratio | 0.56 (0.41–0.75) | 0.58 (0.41–0.74) | Median difference | 0.01 (−0.02 to 0.04) | 0.550 |
| Large niche prevalence (RMT ≤ 3 mm) | 131 (13.2%) | 113 (11.8%) |
Relative risk Risk difference |
0.89 (0.70 to 1.12) −0.01 (−0.04 to 0.02) |
0.310 0.657 |
| Large niche prevalence (RMT/AMT ratio < 50%) | 351 (35.6%) | 337 (35.1%) |
Relative risk Risk difference |
0.98 (0.87 to 1.11) −0.00 (−0.05 to 0.04) |
0.792 0.870 |
| Niche depth (mm), geometric mean (95% CI) e | 3.93 (3.81 to 4.06) | 3.95 (3.83 to 4.07) | Geometric mean ratio | 1.02 (0.97 to 1.08) | 0.498 |
| Niche length (mm), geometric mean (95% CI) e | 4.72 (4.53 to 4.91) | 4.95 (4.78 to 5.13) | Geometric mean ratio | 1.05 (0.99 to 1.11) | 0.056 |
| Niche width (mm), geometric mean (95% CI) e | 5.04 (4.83 to 5.26) | 5.08 (4.87 to 5.29) | Geometric mean ratio | 1.01 (0.95 to 1.07) | 0.737 |
| Niche volume f (mm3), geometric mean (95% CI) e | 22.9 (20.9 to 25.2) | 25.4 (23.2 to 27.7) | Geometric mean ratio | 1.11 (0.98 to 1.27) | 0.106 |
| Presence of intracavitary fluid g | 141 (14.2%) | 157 (16.3%) |
Relative risk Risk difference |
1.14 (0.92 to 1.40) 0.02 (−0.01 to 0.05) |
0.222 0.256 |
| Uterine position | |||||
| Anteverted uterine position | 696 (70.4%) | 688 (71.7%) | Reference category | — | — |
| Stretched uterine position | 65 (6.6%) | 63 (6.6%) |
Relative risk Risk difference |
1.00 (0.72 to 1.40) −0.0 (−0.02 to 0.02) |
0.993 0.910 |
| Retroverted uterine position | 193 (19.5%) | 178 (18.5%) |
Relative risk Risk difference |
0.95 (0.79 to 1.14) −0.01 (−0.05 to 0.03) |
0.582 0.581 |
| Extremely retroverted (angle < 45°) | 34 (3.4%) | 31 (3.2%) |
Relative risk Risk difference |
0.95 (0.59 to 1.53) −0.00 (−0.15 to 0.15) |
0.822 0.994 |
Data are means (SDs), n (%) or medians (IQRs), unless otherwise indicated; N represents the number of women with data available; 95% CI, 95% confidence interval; CS, caesarean section; AMT, adjacent myometrial thickness; RMT, residual myometrium thickness.
Adjusted for timing of CS.
Only recorded when at least one additional haemostatic suture was needed.
Fever, bladder/intestinal lesion, postpartum haemorrhage or other.
Ultrasound outcomes measured at 3 months of follow‐up and presented as smallest RMT or largest niche measurement, either from transvaginal ultrasound or contrast‐enhanced ultrasound, when available.
Only recorded when a niche was present.
Calculated as 1/3 × π × (1/2 × length)2 × depth.
Only available from transvaginal ultrasound, not when contrast was used. Effect estimates are calculated with single‐layer closure as the reference group.