Comparative Evaluation of Blood Loss During Caesarean Section: Electrosurgical Unit Versus Cold Scalpel—A Retrospective Study

Abstract

Background/Objectives: Caesarean section (CS) is the most frequently performed abdominal operation worldwide, and surgical technique continues to evolve to reduce peri-operative morbidity. Electrosurgery is now used in the majority of surgical procedures because it allows simultaneous tissue dissection and haemostasis, yet its systematic use during the abdominal-wall phase of CS remains debated, mainly because of concerns about neonatal safety and uncertain benefit in reducing maternal blood loss. This retrospective study aimed to compare the use of an electrosurgical unit with the conventional cold scalpel in women undergoing elective CS. The primary endpoint was maternal blood loss before hysterotomy; the secondary endpoint was the short-term neonatal effect assessed through umbilical cord blood gas analysis. Methods: We retrospectively reviewed 40 elective caesarean sections performed at a tertiary referral centre between September 2024 and May 2025. In 24 procedures (cold scalpel group), the abdominal wall was opened with a cold scalpel, whereas in 16 procedures (ESU group) an electrosurgical unit was used to dissect the subcutaneous abdominal tissues and the muscle fascia and to achieve subcutaneous haemostasis. Blood loss was quantified by weighing laparotomy gauze and by graduated suction. Continuous variables were compared with Student’s t-test for independent samples. Results: The distribution of pre-hysterotomy blood loss departed from normality in both groups (Shapiro–Wilk p < 0.001 and p = 0.003), and the comparison was therefore performed with the Mann–Whitney U test. Pre-hysterotomy blood loss was significantly lower in the ESU group (median 32.5 mL, IQR 25–50) than in the cold scalpel group (median 60 mL, IQR 50–75; Hodges–Lehmann difference −25 mL, 95% CI −45 to 0; p = 0.025; rank-biserial r = 0.42). Differences in haemoglobin, red blood cell and platelet counts measured 24 h after CS did not reach statistical significance (p = 0.27, 0.70 and 0.66, respectively), nor did total blood loss (p = 0.23). Umbilical cord blood gas analysis showed a mean pH of 7.29 ± 0.06 in the ESU group and 7.26 ± 0.08 in the cold scalpel group (p = 0.55), with comparable Apgar scores. Conclusions: In this retrospective series, the use of an electrosurgical unit during the abdominal-wall phase of elective CS was associated with a significant reduction in blood loss up to hysterotomy, with no detectable short-term effect on the neonate. Given the retrospective, non-randomised design and the limited sample size, these findings are hypothesis-generating and require confirmation in adequately powered randomised or prospective studies.

1. Introduction

Caesarean section (CS) is the most frequently performed abdominal surgery globally and plays a critical role in reducing maternal and perinatal mortality [1,2]. Despite its life-saving benefits, the prevalence of CS continues to rise: the World Health Organisation estimates that approximately 21% of all births are currently delivered by CS, a figure projected to increase to 29% by 2030 [3,4,5]. In Italy, the incidence remains approximately 30%, with regional variations exceeding 40% [6,7,8].

To mitigate post-operative morbidity, surgical techniques have evolved considerably over the past century [4,9,10,11,12,13]—from the traditional Pfannenstiel incision [3] to minimally invasive approaches such as the Joel–Cohen and Pelosi techniques [14,15,16,17]. In parallel with these procedural refinements, the integration of electrosurgery has transformed modern practice [18]. Currently used in over 80% of surgical interventions, electrosurgical units offer the dual advantage of efficient tissue dissection and immediate haemostatic control [19,20,21,22]. In general surgery, the use of electrosurgery for the subcutaneous incision has demonstrated outcomes superior to the cold scalpel, specifically concerning reduced operating time, diminished intra-operative blood loss and lower post-operative pain [23].

Notwithstanding these benefits, the systematic application of the electrosurgical unit during the initial stages of a caesarean section—particularly for the incision of the subcutaneous tissue and the muscle fascia—remains a subject of clinical debate [24,25]. Questions persist regarding neonatal safety and the actual efficacy in reducing maternal blood loss in the obstetric context. Consequently, this study aimed to comparatively evaluate the use of electrosurgery versus the cold scalpel in patients undergoing elective caesarean section. The primary endpoint was the assessment of maternal blood loss before hysterotomy. In contrast, the secondary endpoint was the analysis of short-term effects on neonatal well-being through umbilical cord blood gas analysis, to rule out adverse impacts related to the use of electrosurgical technology near the foetus.

2. Materials and Methods

2.1. Study Design and Setting

This was an observational, comparative, retrospective study. Data were retrieved from the clinical records of women who underwent elective caesarean section at the “Gaetano Martino” University Hospital in Messina (Italy), a tertiary referral centre for obstetrics and gynaecology, between 1 September 2024 and 31 May 2025. All procedures were performed by six operators, each with more than five years of experience in the delivery room.

2.2. Participants and Groups

Women who underwent elective caesarean section during the study period were included and allocated, according to the surgical instrument used during the abdominal-wall phase recorded in the operative notes, to one of two groups. In the cold scalpel group, the subcutaneous tissue and muscle fascia were incised with a cold scalpel, whereas in the ESU group an electrosurgical unit was used to dissect the subcutaneous abdominal tissues and the muscle fascia and to achieve subcutaneous haemostasis. In both groups, the uterine incision was performed with a cold scalpel, in line with standardised institutional protocols consistent with current guidelines [15,16].

2.3. Electrosurgical Technique

In the ESU group, electrosurgery was performed with a VIO^® 200 D electrosurgical generator (Erbe Elektromedizin GmbH, Tübingen, Germany), an isolated-output unit provided with automatic power regulation, which continuously adapts the delivered power to tissue impedance so that the effective output corresponds to the setting selected, and with the NESSY contact-quality monitoring system, which continuously verifies the adhesion and the current distribution of the neutral electrode and interrupts the output in case of inadequate contact. A split, single-use adhesive neutral electrode was applied to the lateral thigh in all cases. Dissection was performed with a monopolar hand-piece fitted with a standard blade electrode.

The electrosurgical unit was used in monopolar cutting mode for the dissection of the subcutaneous adipose tissue and of the rectus fascia, and in monopolar coagulation mode for haemostasis of the subcutaneous layer; bipolar modes were not used. The power settings routinely applied in our unit during the study period ranged between 40 and 50 W, with the generator operating under automatic power regulation. Because of the retrospective design of the study, the exact setting selected for each individual procedure could not be retrieved from the operative notes, and the range reported here corresponds to the departmental practice in force throughout the study period.

The electrosurgical unit was used exclusively for the dissection of the subcutaneous adipose tissue and of the rectus fascia and for haemostasis of the subcutaneous layer. In both groups, the skin incision and the hysterotomy were performed with a cold scalpel; no electrosurgical energy was applied after the uterus had been exposed, and therefore at no time was energy delivered in the immediate proximity of the foetus. In the cold scalpel group, the same layers were dissected with a No. 22 cold scalpel and with Mayo scissors, and haemostasis of the subcutaneous layer was obtained by compression and, where necessary, by suture ligature. All operators had received training in the use of the generator, and the same settings and the same sequence of surgical steps were applied throughout the study period.

2.4. Data Collection

For each patient, the following pre-operative data were retrieved from the clinical records: age; number of previous caesarean sections; spontaneous pregnancy or pregnancy achieved through medically assisted reproduction (MAR); gestational age at the time of caesarean section; drug therapy; pregnancy-related and foetal pathologies; and the results of laboratory tests for haemoglobin, red blood cells and platelets performed on admission.

The following intra-operative data were recorded: surgical instrument used; blood loss from the skin incision to the uterine incision (pre-hysterotomy blood loss); total blood loss; use of a suction device; and any adhesions found during the operation.

Pre-hysterotomy blood loss was quantified by combining two measurements. All the laparotomy gauzes used between the skin incision and the uterine incision were weighed dry before use on a precision scale and weighed again immediately after this phase of the operation, the difference in weight being converted into volume on the basis of the conventional equivalence of 1 g to 1 mL of blood. Where suction was used before hysterotomy, the volume collected in the graduated canister—empty at the start of the procedure—was added to the gravimetric estimate; in practice this occurred in only 2 of the 40 procedures, so that the estimate is essentially gravimetric. It should be noted that this measurement window ends before the uterus is opened: no amniotic fluid is therefore present in the surgical field, no irrigation is performed during this phase in our institutional protocol, and no fluid other than blood contributes to either measurement. This is one of the reasons why pre-hysterotomy blood loss, rather than total blood loss, was chosen as the primary outcome.

Total blood loss was recorded from the skin incision to skin closure with the same method, with the difference that after hysterotomy the volume collected by suction inevitably includes amniotic fluid, which the operative records do not allow to be separated from blood. This variable was available for only 26 of the 40 patients (8 in the ESU group and 18 in the cold scalpel group) because, in the remaining 14 procedures, the total figure had not been entered in the operative notes; since the study is retrospective, this information could not be reconstructed. The missing data are therefore attributable to incomplete documentation rather than to any characteristic of the patients or of the procedures, but the possibility of a non-random pattern cannot be formally excluded, and total blood loss is accordingly treated throughout as a secondary and exploratory outcome.

For each newborn, the following data were recorded at birth: pH values obtained from cord blood gas analysis; Apgar score at 1 min; and Apgar score at 5 min. Finally, the results of blood chemistry tests for haemoglobin, red blood cells and platelets performed on the mothers 24 h after delivery were collected and recorded.

2.5. Outcomes

The primary outcome was maternal blood loss measured from the skin incision to the uterine incision (pre-hysterotomy blood loss). Secondary outcomes were total blood loss, the peri-operative variation in haemoglobin, red blood cell and platelet counts, and short-term neonatal well-being assessed through umbilical cord pH and Apgar scores at 1 and 5 min.

2.6. Statistical Analysis

Descriptive statistics were computed with Microsoft Excel (Microsoft Corporation, Redmond, WA, USA); assumption checks, hypothesis tests, effect sizes and confidence intervals were computed with Python 3.11 using the SciPy library. The normality of the distribution of the continuous variables was assessed in each group with the Shapiro–Wilk test and the homogeneity of variances with Levene’s test. Continuous variables satisfying the assumption of normality are presented as mean ± standard deviation and were compared with Student’s t-test for independent samples, with the mean difference, its 95% confidence interval and Cohen’s d. Variables for which normality was rejected in at least one group are presented as median (interquartile range), in addition to mean ± standard deviation, and were compared with the Mann–Whitney U test, with the Hodges–Lehmann estimate of the difference between medians, its 95% confidence interval and the rank-biserial correlation as effect size. The choice of test for each variable was therefore determined by the assumption check and not by the outcome of the comparison. Categorical variables are presented as absolute frequencies and percentages and were compared with Fisher’s exact test. A two-sided p-value < 0.05 was considered statistically significant.

No a priori sample size calculation was performed, since the study is a retrospective analysis of all the consecutive elective caesarean sections carried out in the study period, and the sample size was therefore determined by the available data rather than chosen. A sensitivity power analysis was performed instead: with 16 and 24 patients per group, a two-sided alpha of 0.05 and 80% power, the study is able to detect only differences corresponding to an effect size of d ≥ 0.90, that is, large effects. For the effect size actually observed on the primary outcome (d = 0.49) the achieved power is approximately 32%, and approximately 66 patients per group would be required to detect it with 80% power. These figures are reported here so that the non-significant results of this study—that is, all the outcomes other than pre-hysterotomy blood loss—are interpreted as inconclusive rather than as evidence of equivalence.

2.7. Ethical Considerations

The study was conducted in accordance with the principles of the Declaration of Helsinki. Given the retrospective and observational design of the study, which was based on the analysis of clinical data collected during routine care, an opinion from the Institutional Ethics Committee was not required in accordance with current local regulations. Nevertheless, written informed consent covering participation and the secondary use of clinical data for research purposes had been obtained from all participating women.

3. Results

3.1. Description of the Overall Sample

During the study period, 40 elective caesarean sections were reviewed. Of these, 24 constituted the cold scalpel group, in which the caesarean section was performed with a cold scalpel, and 16 constituted the ESU group, in which an electrosurgical unit was used to dissect the subcutaneous abdominal tissues and muscle fascia and to achieve subcutaneous haemostasis. In all observed cases, the perinatal outcome was favourable, with no complications reported in the immediate post-partum checks for either mothers or newborns.

The overall sample comprised 40 patients with a mean age of 33.8 ± 5.04 years and a mean gestational age of 38.55 ± 1.60 weeks. In 10% of the sample, the pregnancy had been achieved following assisted reproductive technology (ART). Thirty-three per cent of women had never undergone a caesarean section, 53% had undergone one previous caesarean section, and the remaining 15% had undergone two. Of the 40 patients, 6 were taking medication for hypertensive or thrombotic disorders—namely antihypertensive, anticoagulant and antiplatelet drugs such as methyldopa, labetalol, nifedipine, heparin and acetylsalicylic acid. In terms of comorbidities, 15% of patients had intra-abdominal adhesions, 20% had gestational diabetes, 5% had pre-gestational hypertension, 7.5% had gestational hypertension and 2.5% (1/40) had anterior placenta praevia.

Blood loss measured between the skin incision and the uterine incision amounted to 64.25 ± 45.24 mL. Blood loss from the skin incision to skin closure, recorded in a sub-sample of 26 patients, was 1405.77 ± 675.03 mL. The mean admission values for haemoglobin, red blood cells and platelets were, respectively: Hb 11.41 ± 0.95 g/dL; RBC 4,103,500 ± 413,618/µL; PLT 239,425 ± 84,073/µL. Polyhydramnios was present in 3 of the 40 pregnancies (7.5%). At birth, the mean cord pH was 7.27 ± 0.07, and the mean Apgar score was 8.78 ± 1.03 at 1 min and 9.60 ± 0.59 at 5 min. Twenty-four hours after surgery, blood tests showed the following values: Hb 10.20 ± 1.41 g/dL; RBC 3,613,500 ± 516,098/µL; PLT 223,825 ± 88,932/µL.

3.2. Cold Scalpel Group (Control)

The cold scalpel group comprised 24 patients with a mean age of 33.83 ± 4.89 years and a mean gestational age of 38.73 ± 1.39 weeks. One patient had conceived through ART. Thirty-eight per cent had never had a caesarean section, 54% had undergone one previous caesarean section, and the remaining 8% had undergone two. Three of the 24 patients were taking medication, specifically methyldopa and heparin. As regards comorbidities, 20.8% had intra-abdominal adhesions, 25% had gestational diabetes, 4.2% had pre-gestational hypertension, 8.3% had gestational hypertension, and 4.2% had anterior placenta praevia.

Blood loss measured between the skin incision and the uterine incision was 72.92 ± 44.99 mL, while total blood loss from the skin incision to skin closure, recorded in a sub-sample of 18 patients, was 1336.11 ± 727.97 mL. The mean admission values were: Hb 11.40 ± 0.93 g/dL; RBC 4,133,750 ± 461,526/µL; PLT 241,375 ± 88,290/µL. Polyhydramnios was present in 1 of the 24 pregnancies (4.2%). At birth, the mean cord pH was 7.26 ± 0.08, with a mean Apgar score of 8.75 ± 1.07 at 1 min and 9.46 ± 0.66 at 5 min. Twenty-four hours after surgery, blood tests showed: Hb 9.99 ± 1.26 g/dL; RBC 3,596,666 ± 469,797/µL; PLT 227,625 ± 89,448/µL.

3.3. ESU Group (Experimental)

The ESU group comprised 16 patients with a mean age of 33.75 ± 5.43 years and a mean gestational age of 38.27 ± 1.88 weeks. Three patients had conceived through ART. Twenty-five per cent had never undergone a caesarean section, 50% had undergone one previous caesarean section and the remaining 25% had undergone two. Three of the 16 patients were taking medication, specifically methyldopa, labetalol, nifedipine, acetylsalicylic acid and heparin. As regards comorbidities, 6.25% had intra-abdominal adhesions, 12.5% had gestational diabetes, and 6.25% had pre-gestational hypertension and 6.25% gestational hypertension.

Blood loss measured between the skin incision and the uterine incision was 51.25 ± 43.80 mL, while total blood loss from the skin incision to skin closure, recorded in a sub-sample of 8 patients, was 1562.50 ± 547.56 mL. The mean admission values were: Hb 11.43 ± 1.02 g/dL; RBC 4,058,125 ± 338,432/µL; PLT 236,500 ± 80,059/µL. Polyhydramnios was present in 2 of the 16 pregnancies (12.5%). At birth, the mean cord pH was 7.29 ± 0.06, with a mean Apgar score of 8.81 ± 0.98 at 1 min and 9.81 ± 0.40 at 5 min. Twenty-four hours after surgery, blood tests showed: Hb 10.50 ± 1.60 g/dL; RBC 3,638,750 ± 594,114/µL; PLT 218,125 ± 90,756/µL.

3.4. Cold Scalpel Group Versus ESU Group

Table 1. Baseline characteristics of the two groups.

Characteristic	ESU Group (n = 16)	Cold Scalpel Group (n = 24)	p Value
Maternal age (years)	33.75 ± 5.43	33.83 ± 4.89	0.96
Gestational age (weeks)	38.27 ± 1.88	38.73 ± 1.39	0.51 a
Pre-operative Hb (g/dL)	11.43 ± 1.02	11.40 ± 0.93	0.91
Pre-operative RBC (/µL)	4,058,125 ± 338,432	4,133,750 ± 461,526	0.58
Pre-operative PLT (/µL)	236,500 ± 80,059	241,375 ± 88,290	0.96 a
Assisted reproductive technology, n (%)	3 (18.8)	1 (4.2)	0.28 b
Ongoing medication, n (%) b	3 (18.8)	3 (12.5)	0.67 b
Gestational diabetes, n (%)	2 (12.5)	6 (25.0)	0.44 b
Pre-gestational hypertension, n (%)	1 (6.3)	1 (4.2)	1.00 b
Gestational hypertension, n (%)	1 (6.3)	2 (8.3)	1.00 b
Anterior placenta praevia, n (%)	0 (0.0)	1 (4.2)	1.00 b
Intra-abdominal adhesions, n (%)	1 (6.3)	5 (20.8)	0.37 b
No previous caesarean section, n (%)	4 (25.0)	9 (37.5)	0.50 b
One previous caesarean section, n (%)	8 (50.0)	13 (54.2)	1.00 b
Two previous caesarean sections, n (%)	4 (25.0)	2 (8.3)	0.20 b

Continuous data are presented as mean ± standard deviation; categorical data as n (%). Hb = haemoglobin; RBC = red blood cells; PLT = platelets; ESU = electrosurgical unit. ^a Mann–Whitney U test (normality rejected by the Shapiro–Wilk test). ^b Fisher’s exact test. All the remaining comparisons: Student’s t-test for independent samples.

and

Table 2. Comparison of the outcomes between the two groups.

Outcome	ESU Group (n = 16) Mean ± SD/Median (IQR)	Cold Scalpel Group (n = 24) Mean ± SD/Median (IQR)	Difference (95% CI)	p	Effect Size
Pre-hysterotomy blood loss (mL)	51.25 ± 43.80 32.50 (25.00–50.00)	72.92 ± 44.99 60.00 (50.00–75.00)	−25.00 (−45.00 to 0.00)	0.02 a	r = 0.42
Total blood loss (mL) c	1562.50 ± 547.56 1650.00 (1150.00–2025.00)	1336.11 ± 727.97 1150.00 (1000.00–1675.00)	375.00 (−300.00 to 900.00)	0.23 a	r = 0.31
Post-operative Hb, 24 h (g/dL)	10.50 ± 1.60 10.20 (9.20–11.88)	9.99 ± 1.26 10.10 (9.20–10.75)	0.51 (−0.41 to 1.43)	0.27 b	d = 0.36
Hb drop (Δ Hb, g/dL)	0.93 ± 1.26 1.00 (0.50–1.60)	1.40 ± 1.08 1.40 (0.92–2.02)	−0.47 (−1.23 to 0.28)	0.21 b	d = 0.41
Post-operative RBC, 24 h (/µL)	3,638,750 ± 594,114 3,500,000 (3,175,000–3,820,000)	3,596,667 ± 469,798 3,615,000 (3,290,000–3,920,000)	−80,000 (−330,000 to 290,000)	0.70 ᵃ	r = 0.08
RBC drop (Δ RBC, /µL)	419,375 ± 365,795 445,000 (170,000–627,500)	537,083 ± 358,699 545,000 (305,000–740,000)	−117,708 (−353,913 to 118,496)	0.32 b	d = 0.33
Post-operative PLT, 24 h (/µL)	218,125 ± 90,757 210,000 (155,750–245,000)	227,625 ± 89,449 218,000 (166,000–270,000)	−12,000 (−59,000 to 41,000)	0.66 a	r = 0.09
PLT drop (Δ PLT, /µL)	18,375 ± 34,587 21,000 (10,500–40,500)	13,750 ± 74,494 30,000 (2750–51,250)	−5500 (−29,000 to 16,000)	0.53 a	r = 0.12
Umbilical cord pH	7.287 ± 0.059 7.295 (7.265–7.330)	7.265 ± 0.081 7.300 (7.255–7.320)	0.010 (−0.020 to 0.040)	0.55 a	r = 0.11
1 min Apgar score	8.8 ± 1.0 9.0 (8.8–9.0)	8.8 ± 1.1 9.0 (8.8–9.0)	0.0 (−1.0 to 1.0)	1.00 a	r = 0.00
5 min Apgar score	9.8 ± 0.4 10.0 (10.0–10.0)	9.5 ± 0.7 10.0 (9.0–10.0)	0.0 (0.0 to 1.0)	0.07 a	r = 0.29

Each cell reports mean ± standard deviation on the first line and median (interquartile range) on the second. Differences are calculated as ESU group minus cold scalpel group. CI = confidence interval; Δ = difference between the pre-operative value and the value measured 24 h after surgery. ^a Mann–Whitney U test (normality rejected by the Shapiro–Wilk test in at least one group); the difference is the Hodges–Lehmann estimate and the effect size is the rank-biserial correlation r. ^b Student’s t-test; the difference is the difference between means and the effect size is Cohen’s d. ^c Available in a sub-sample of 26 patients (8 in the ESU group, 18 in the cold scalpel group); see Section 2.4.

summarise the variables examined in this study: Table 1 reports the baseline characteristics of the two groups and Table 2 the outcomes, each with the mean difference between groups, its 95% confidence interval, the p-value and the effect size.

The two groups were comparable at baseline. No statistically significant difference was found for maternal age (p = 0.96), gestational age (p = 0.51) or pre-operative haemoglobin, red blood cell and platelet counts (p = 0.91, 0.58 and 0.96, respectively), nor for any of the clinical characteristics potentially relevant to bleeding that were recorded: assisted reproductive technology, ongoing medication, gestational diabetes, pre-gestational and gestational hypertension, anterior placenta praevia, intra-abdominal adhesions and number of previous caesarean sections (all p ≥ 0.20; Table 1). It should nevertheless be emphasised that, with groups of this size, the absence of a statistically significant imbalance does not exclude clinically meaningful differences, and that residual confounding cannot be ruled out; this point is addressed in the Discussion.

The Shapiro–Wilk test rejected the assumption of normality in at least one group for gestational age, post-operative red blood cell and platelet counts, the platelet delta, pre-hysterotomy blood loss, total blood loss, umbilical cord pH and both Apgar scores; these variables were therefore compared with the Mann–Whitney U test and are reported as median (interquartile range) in addition to mean ± standard deviation. The remaining variables satisfied the assumption and were compared with Student’s t-test. Levene’s test did not indicate a violation of the homogeneity of variances for any variable (all p ≥ 0.06). The test applied to each variable is indicated in Table 1 and Table 2.

Although differences were found between the two groups in haemoglobin, red blood cell and platelet levels 24 h after caesarean section, these were not statistically significant (p = 0.27, 0.70 and 0.66, respectively; Table 2). The peri-operative variation in blood values—calculated for each patient as the difference between pre-operative and post-operative haemoglobin, platelet and red blood cell counts—was also analysed.

The comparison of these differences between the two groups showed a smaller decrease in haemoglobin and red blood cell levels in the ESU group. The haemoglobin delta was 0.93 ± 1.26 g/dL in the ESU group versus 1.40 ± 1.08 g/dL in the cold scalpel group (mean difference −0.47, 95% CI −1.23 to 0.28; p = 0.21; d = 0.41), while the red blood cell delta was 419,375 ± 365,795/µL versus 537,083 ± 358,699/µL (mean difference −117,708, 95% CI −353,913 to 118,496; p = 0.32; d = 0.33). Both comparisons show a favourable trend that did not reach statistical significance.

The platelet delta did not follow the same direction: it was slightly greater in the ESU group (median 21,000/µL, IQR 10,500–40,500) than in the cold scalpel group (median 30,000/µL, IQR 2750–51,250), with a Hodges–Lehmann difference of −5500/µL (95% CI −29,000 to 16,000; Mann–Whitney p = 0.53; rank-biserial r = 0.12). The parametric comparison of the means gave a concordant result (p = 0.82). This divergence is addressed in the Discussion.

The primary outcome, blood loss measured up to hysterotomy, was significantly lower in the ESU group. The median was 32.5 mL (IQR 25–50) in the ESU group and 60 mL (IQR 50–75) in the cold scalpel group, with a Hodges–Lehmann difference between medians of −25 mL (95% CI −45 to 0), a Mann–Whitney p-value of 0.025 and a rank-biserial correlation of 0.42, corresponding to a moderate effect. The corresponding means were 51.25 ± 43.80 mL and 72.92 ± 44.99 mL (Cohen’s d = 0.49). We note that the parametric comparison of these means does not reach significance (p = 0.14); since the distribution of this variable departs markedly from normality in both groups, with a pronounced right skew and a concentration of values on rounded figures, the non-parametric test is the appropriate one, and the choice was determined by the assumption check rather than by the result.

Total blood loss, recorded from the skin incision to skin closure in the sub-sample of 26 patients for whom it was available, was conversely higher in the ESU group (median 1650 mL, IQR 1150–2025) than in the cold scalpel group (median 1150 mL, IQR 1000–1675), without reaching statistical significance (Hodges–Lehmann difference 375 mL, 95% CI −300 to 900; p = 0.23).

The data collected on newborns were aimed at analysing the possible consequences that the use of the electrosurgical unit could have on them. Umbilical cord blood gas analysis performed at birth showed a median pH of 7.295 (IQR 7.265–7.330) in the ESU group and 7.300 (IQR 7.255–7.320) in the cold scalpel group, with no significant difference (p = 0.55). Apgar scores at 1 and 5 min were also comparable: the 1 min score had a median of 9 in both groups (p = 1.00), and the 5 min score a median of 10 in both groups, with a narrower distribution in the ESU group (IQR 10–10 versus 9–10; p = 0.07). None of the neonatal comparisons reached statistical significance.

4. Discussion

Analysis of the data collected showed a significant reduction in blood loss up to hysterotomy in the group operated on with an electrosurgical unit, together with a smaller, non-significant decline in haemoglobin and red blood cell counts, and no detectable short-term adverse effect on neonatal health.

First, the median blood loss up to hysterotomy was 32.5 mL in the ESU group against 60 mL in the cold scalpel group, a difference of −25 mL (95% CI −45 to 0; p = 0.025) with a moderate effect size. In absolute terms the difference is modest and, in a patient with normal haemostasis and no obstetric haemorrhage, of limited clinical consequence in itself; its interest lies rather in the fact that it is obtained in the only phase of the operation in which the two techniques actually differ, and that it is consistent in direction with the smaller haemoglobin decline observed 24 h after surgery, even though the latter does not reach significance. Three considerations should temper the interpretation of this result. The upper limit of the confidence interval touches zero, so the estimate is at the margin of significance. The design is retrospective and non-randomised, so statistical significance does not establish causation. Additionally, the distribution of intra-abdominal adhesions, discussed below, offers a plausible alternative explanation that this study cannot exclude.

These results are consistent with those reported in the literature. Among the available studies, that of Elbohoty et al. represents a particularly relevant direct comparison: conducted on 130 women, it reported lower blood loss in the electrosurgical group (11 g vs. 20 g; p = 0.001), together with reduced incision time and lower analgesic use [26]. It should be noted that the electrosurgical unit, thanks to its ability to dissect and coagulate vessels simultaneously, proved to be a valuable tool, especially in patients with adhesions (15% of our overall sample)—a fairly common condition, considering that 68% of patients had already undergone at least one caesarean section [9].

Therefore, neither the Apgar scores at 1 and 5 min nor the pH values obtained through cord blood gas analysis suggest any adverse short-term effect of the electrosurgical unit on the newborn. These data are reassuring, but they cannot be taken as evidence that no foetal risk exists. With 16 neonates exposed to the technique, an adverse event that was not observed in our series could still occur with a frequency of up to approximately 19% (upper limit of the 95% confidence interval by the rule of three), and the study has no power to detect rare events or small differences in the parameters examined. Our findings are therefore compatible with the absence of a clinically relevant short-term effect, but they do not demonstrate it.

Again, these data are in line with the literature. A recent observational study conducted by Gokulu et al. in 2024 [27] analysed 552 patients who underwent elective caesarean section, of whom 274 had the incision made with an electrosurgical unit and 278 with a cold scalpel, to evaluate any consequences of the electrosurgical unit on the foetus through the analysis of neonatal vital parameters. The results showed that newborns of mothers who underwent incision with an electrosurgical unit had significantly higher umbilical cord heart rate, pH and pO2 and higher 1 min Apgar scores, as well as a lower incidence of neonatal hypoglycaemia. A slight reduction in serum calcium was also observed, although it remained within physiological values. The variations found were modest, transient and within normal limits, and there were no maternal or foetal deaths, no serious morbidity and no cases of burns.

According to the authors, these effects are linked to stimulation of the foetal adrenal medulla by high-frequency current, resulting in the release of catecholamines. The study did not reveal any significant complications associated with the use of electrosurgery during caesarean section; on the contrary, the acute stress caused by the passage of electric current appears to promote a transient improvement in neonatal adaptation [27].

Two of our findings do not follow the direction of the primary endpoint and deserve explicit comment: the reduction in platelet count was marginally greater in the ESU group, and total blood loss measured up to skin closure was also higher in this group. We do not interpret either finding as evidence of an unfavourable effect of electrosurgery, for the reasons set out below.

As regards platelets, the difference between the two deltas (Hodges–Lehmann estimate −5500/µL; 95% CI −29,000 to 16,000; p = 0.53) is smaller than the combined analytical and biological variability of automated platelet counting, which at these concentrations corresponds to approximately ±12,000–24,000/µL; the difference therefore lies below the resolution of the measurement itself. The dispersion of the data is also substantial, particularly in the cold scalpel group, and the effect size is negligible (rank-biserial r = 0.12) when compared with those observed for the haemoglobin delta (d = 0.41) and for pre-hysterotomy blood loss (r = 0.42). From a physiological standpoint, moreover, the platelet count in the first 24 h after caesarean section is not a reliable surrogate for surgical blood loss: it is influenced principally by haemodilution secondary to intra-operative fluid administration, by platelet consumption at the placental bed and by the acute-phase response to delivery—processes that are independent of the instrument used to divide the subcutaneous tissue and the fascia, and quantitatively far greater than any contribution attributable to it. A divergence between the platelet delta and the haemoglobin and red blood cell deltas is therefore to be expected in a sample of this size.

As regards total blood loss, this variable was available in only 26 of the 40 patients (8 in the ESU group and 18 in the cold scalpel group), its dispersion is very wide (SD 548 and 728 mL, respectively), and above all it reflects the entire operation, including hysterotomy, delivery of the placenta and uterine closure—phases in which no electrosurgical energy was applied in either group and which account for the overwhelming majority of intra-operative bleeding. The primary endpoint was deliberately restricted to blood loss measured up to hysterotomy, that is, to the only phase in which the two techniques actually differ; it is within this window that the ESU group showed lower blood loss, with a moderate effect size.

Taken together, these observations indicate that the difference in pre-hysterotomy blood loss, although statistically significant, should be interpreted with caution, and that the accompanying trends in the haemoglobin and red blood cell deltas remain unconfirmed. As detailed in Section 2.6, the sensitivity power analysis shows that a sample of 16 and 24 patients can detect only large effects (d ≥ 0.90); the secondary outcomes of this study are therefore substantially underpowered, and their lack of statistical significance cannot be interpreted as evidence of the absence of a difference.

A further methodological consideration concerns the way haemostasis and blood loss were assessed. Our study relied on the gravimetric estimation of blood loss and on static laboratory parameters—haemoglobin, red blood cell and platelet counts—measured 24 h after surgery. These indicators are simple and widely used, but they describe the consequences of bleeding rather than the functional state of haemostasis; they are influenced by peri-operative fluid shifts, and they are insensitive to the dynamic changes in coagulation that occur during surgery.

Viscoelastic testing and the assessment of fibrinogen-related parameters offer a more direct and objective approach in this respect. In a recent prospective longitudinal study of major non-cardiac surgery, Hosala et al. [28] documented the peri-operative dynamics of coagulation using rotational thromboelastometry alongside conventional assays, reporting a strong correlation between Clauss fibrinogen and the FIBTEM maximum clot firmness and an intra-operative decline in fibrinogen and antithrombin III; notably, pre-operative fibrinogen was not associated with intra-operative blood loss in their cohort. Their findings are relevant here in two ways: they illustrate that viscoelastic testing can provide a rapid functional estimate of fibrinogen availability during surgery, and they caution against assuming a simple relationship between a single static coagulation parameter and the amount of bleeding. This is of particular interest in obstetrics, where fibrinogen is recognised as an early and sensitive marker of the severity of post-partum haemorrhage.

Incorporating point-of-care viscoelastic testing and fibrinogen measurement into the design of a future prospective study would allow the effect of the incision technique on haemostasis to be assessed directly, rather than inferred from post-operative blood counts, and would considerably strengthen the interpretation of differences of the magnitude observed here. We regard this as the most promising methodological development for the confirmatory study that our findings call for.

This study has several limitations. Its retrospective design and the relatively small sample size, together with the unequal group sizes, reduce statistical power and may account for the lack of statistical significance despite the favourable trends observed. Allocation to the two techniques was not randomised but reflected the preference of the operating surgeon recorded in the operative notes, which may have introduced selection bias; the two groups were nonetheless comparable for maternal age, gestational age and baseline laboratory values. The assessment was not blinded, and the gravimetric estimation of blood loss, although widely used, is subject to a degree of imprecision; total blood loss was moreover available in only 26 of the 40 patients. The single-centre setting and the involvement of six different operators may also introduce variability in surgical technique. These limitations should be taken into account when interpreting the results and underline the need for confirmation in adequately powered prospective studies. Based on the observations reported here and their consistency with the available literature, the use of electrosurgical units during caesarean section appears to warrant further prospective studies aimed at consolidating its advantages.

The two groups did not differ significantly in any of the recorded characteristics potentially relevant to bleeding—previous caesarean sections, intra-abdominal adhesions, maternal comorbidities and ongoing medication (Table 1)—but this comparability should not be overstated: with 16 and 24 patients, the comparisons of these characteristics are themselves severely underpowered, and a clinically meaningful imbalance could easily go undetected. The distribution of intra-abdominal adhesions is a case in point: adhesions were three times more frequent in the cold scalpel group (20.8% versus 6.3%), a difference that does not reach statistical significance (p = 0.37) but that plausibly favours the ESU group on the primary outcome, since adhesions prolong and complicate the abdominal-wall phase. A multivariable adjustment is not feasible with 40 patients and events of this frequency, and we have therefore refrained from attempting one; residual confounding consequently remains the most important alternative explanation for the trends we observed, together with chance.

A further limitation inherent in the retrospective design is that, although the electrosurgical technique and the range of power settings applied in our unit were standardised throughout the study period, the exact generator setting used in each individual procedure could not be retrieved from the operative notes.

Finally, although the assumptions underlying each test were formally verified and the test applied to each variable was selected on the basis of that verification, the limited size of the two groups inevitably reduces the precision of the estimates. This is reflected in the width of the confidence intervals reported in Table 2 and, for the primary outcome, in the fact that the upper limit of the confidence interval touches zero.

Finally, follow-up was limited to the first 24 h after surgery, and outcomes such as post-operative pain, wound infection, wound dehiscence and duration of hospital stay—for which differences between the two techniques have been reported in general surgery—were not assessed.

5. Conclusions

The present study evaluated the use of electrosurgery in obstetrics—a field traditionally characterised by a cautious approach to electrosurgical devices, given the need to ensure the simultaneous safety of both mother and neonate. The comparative analysis showed a statistically significant reduction in blood loss up to hysterotomy in the group operated on with an electrosurgical unit, while none of the secondary outcomes—post-operative haemoglobin, red blood cell and platelet counts, total blood loss—reached statistical significance, and no short-term adverse effect on the neonate was recorded. These findings are consistent with the existing literature and support the hypothesis that electrosurgery represents a valid alternative to the cold scalpel for the abdominal-wall phase of caesarean section, particularly in cases requiring meticulous haemostatic control, given the high prevalence of patients with previous caesarean sections and abdominal adhesions. In light of the retrospective, non-randomised design, the limited sample size and the borderline confidence interval of the primary result, however, the present findings should be regarded as hypothesis-generating: they support the short-term safety of the technique and justify the design of adequately powered randomised or prospective studies, but they do not by themselves warrant a recommendation for the routine adoption of electrosurgery during caesarean section.