Abstract

Objective

To compare maternal and neonatal outcomes among women undergoing cesarean section (CS) with concomitant myomectomy, women with uterine fibroids managed conservatively at cesarean delivery, and women without uterine fibroids.

Material and Methods

This retrospective cohort study included women who delivered by CS between May 2017 and December 2024. Patients were classified into three groups: CS with myomectomy (Group 1), CS with fibroids without myomectomy (Group 2), and CS without fibroids (Group 3). Maternal outcomes included perioperative changes in hemoglobin, hematocrit, and platelet counts, transfusion requirement, and length of hospital stay. Neonatal outcomes included birth weight, birth length, and Apgar scores. Appropriate parametric and non-parametric statistical tests were used for group comparisons.

Results

The study cohort numbered 682 with 252 (36.95%), 178 (26.1%) and 252 (36.95%) women in Groups 1, 2 and 3, respectively.  Postoperative hemoglobin, hematocrit, and platelet levels differed significantly among the three groups (all p<0.05). However, hemoglobin deficit did not differ significantly between Group 1 and Group 2 (p=0.346), while both groups showed greater hemoglobin deficit than Group 3 (p<0.05). Transfusion rates and hospitalization duration differed significantly between groups (p<0.05), with longer hospital stay observed in transfused patients regardless of group. Maximum myoma volume was higher in Group 1, whereas myoma count was greater in Group 2 and total myoma volume was comparable between these groups (p=0.09). Neonatal birth weight was significantly lower in Group 2 compared with Groups 1 and 3 (p<0.05), while no difference was observed between Groups 1 and 3 (p=0.956). Other neonatal outcomes were similar.

Conclusion

Cesarean myomectomy was associated with larger changes in hematologic parameters and transfusion rates; however, hemoglobin deficit appears related to fibroid presence rather than myomectomy itself. Neonatal outcomes were not adversely affected by cesarean myomectomy, whereas untreated fibroids appeared to be associated with lower birth weight.

Introduction

Uterine leiomyomas (fibroids) are the most common benign tumors of the female reproductive system and frequently coexist with pregnancy (1). Although the overall prevalence of fibroids in pregnancy varies widely depending on diagnostic modality and population characteristics, recent studies estimate rates ranging from approximately 2% to 12% in pregnant women, with higher prevalence reported in advanced maternal age and multiparous populations (2, 3). Fibroids originate from monoclonal proliferation of smooth muscle cells within the myometrium and exhibit heterogeneous growth patterns influenced by hormonal, genetic, and vascular factors. Given their high prevalence, fibroids represent a frequent clinical challenge in obstetric practice.

While many fibroids remain asymptomatic during pregnancy, their presence has been associated with a spectrum of obstetric complications, including malpresentation, preterm birth, placental abruption, cesarean delivery, and postpartum hemorrhage (4, 5). Fibroid size, number, and location, and in particularly large intramural or lower-segment myomas that may obstruct the uterine incision site or alter placental perfusion, appear to play an important role in determining obstetric risk. In addition to maternal morbidity, fibroid-related alterations in uterine architecture and perfusion may influence fetal growth and neonatal outcomes, although findings remain inconsistent across studies (6-8).

Management of uterine fibroids at the time of cesarean section (CS) represents one of the most debated topics in contemporary obstetric surgery. Historically, cesarean myomectomy was discouraged due to concerns regarding uncontrollable hemorrhage, prolonged operative time, and increased risk of peripartum hysterectomy (9, 10). Consequently, fibroid removal during cesarean delivery was traditionally limited to pedunculated or easily accessible subserosal lesions. However, advances in surgical techniques, anesthesia, hemostatic strategies, and perioperative blood management have prompted renewed interest in the safety and feasibility of cesarean myomectomy.

In recent years, multiple observational studies and meta-analyses have reported comparable maternal outcomes between cesarean myomectomy and cesarean delivery without myomectomy in selected patient populations, particularly when procedures are performed by experienced surgeons. Reported outcomes suggest that although cesarean myomectomy may be associated with increased operative complexity, rates of transfusion, severe hemorrhage, and hysterectomy are not consistently higher than those observed in patients with fibroids who do not undergo myomectomy. Nevertheless, heterogeneity in study design, patient selection, fibroid characteristics, perioperative management and outcome definitions have limited the generalizability of existing evidence, and current international guidelines remain cautious, emphasizing individualized decision-making rather than universal recommendations (11).

Importantly, many prior studies have focused primarily on comparisons between cesarean myomectomy and cesarean delivery without fibroids, potentially confounding the effects of fibroid presence with those of surgical intervention (10, 12). Fewer investigations have incorporated a three-group comparative framework that separately evaluates patients undergoing cesarean myomectomy, patients with fibroids managed conservatively at cesarean delivery, and patients without fibroids. Such a design is essential to disentangle the contribution of fibroid burden itself from the incremental impact of myomectomy on maternal hematologic parameters, transfusion requirements, and postoperative recovery. This limitation hampers accurate risk stratification and may lead to overly conservative or inconsistent surgical decision-making in contemporary obstetric practice.

Therefore, the aim of the present study was to comprehensively compare maternal and neonatal outcomes among three distinct groups and to disentangle the impact of fibroid burden itself from the incremental effects of myomectomy at the time of cesarean delivery. The primary outcomes included perioperative changes in hemoglobin and hematocrit levels, transfusion requirement, and length of hospital stay. Secondary outcomes focused on neonatal parameters, including birth weight, birth length , and Apgar scores. By employing a three-group analytical approach, it was hoped to provide clinically relevant evidence to inform surgical decision-making regarding cesarean myomectomy.

Material and Methods

This retrospective cohort study was conducted between May 2017 and December 2024. The study included pregnant women who delivered via CS. Approval from the University of Health Sciences Türkiye, Balıkesir Atatürk City Hospital Ethics Committee was sought prior to the study and it conforms to the provisions of the Declaration of Helsinki (approval no: 2025/02/20, date: 20.02.2025). As this was a retrospective study, informed consent was waived. Inclusion criteria consisted of women aged 18 years or older with no additional comorbidities. This approach was adopted to minimize confounding effects of systemic comorbidities on perioperative and neonatal outcomes. Exclusion criteria included patients with ovarian cysts, any malignancy, diabetes, hypertension, other chronic diseases, and multiple pregnancies.

Demographic and clinical data were retrospectively extracted from the hospital’s electronic medical record system. Maternal variables included age, gestational age at delivery, body mass index (BMI), gravidity, parity, and abortion history. BMI was calculated as weight (kg) divided by height squared (m²). Laboratory parameters included preoperative and postoperative hemoglobin, hematocrit, platelet count, neutrophil count, and lymphocyte count. Additional variables included transfusion requirement, length of hospital stay, and myoma-related characteristics (number of myomas, total myoma volume, and maximum myoma volume). Neonatal outcomes included birth weight, birth length , and Apgar scores at 1 and 5 minutes.

Myoma volume was calculated using the ellipsoid formula (V = π/6×length×width×depth). Total myoma volume (total V) was defined as the sum of volumes of all detected myomas, and the largest individual myoma volume was defined as maximum myoma volume (max V). Laboratory analyses were performed using AU5800 (Beckman Coulter, California, USA) and pocH-100i (Sysmex Corporation, Japan). The same reagent kits and internal quality control procedures were used throughout the study period. None of the fibroids included in the study were submucosal. The majority of lesions were subserosal or intramural-subserosal fibroids.

Patients were categorized into three groups: Group 1, CS  with concomitant myomectomy; Group 2, CS  in the presence of uterine myomas without myomectomy; and Group 3, CS without uterine myomas. Group 3 was selected to match the sample size of the cesarean myomectomy group, allowing balanced three-group comparisons. A post-hoc power analysis was performed assuming an 80% power, a 95% confidence level, and a 5% margin of error. Myomectomy in Group 1 was performed during CS by experienced obstetric surgeons. Hemostasis during cesarean myomectomy was achieved using electrocautery, uterine compression sutures, and routine oxytocin infusion. No additional vasoconstrictive agents, such as vasopressin, were used, and uterine artery ligation or balloon tamponade was not routinely performed. Group 3 patients were consecutively selected from women without uterine myomas who underwent CS during the same study period.

Statistical analysis

All statistical analyses were performed using Stata version 17 (StataCorp, USA). Normality of continuous variables was assessed using the Shapiro-Wilk test. Normally distributed variables were analyzed using one-way analysis of variance (ANOVA), while non-normally distributed variables were analyzed using the Kruskal-Wallis test. Post-hoc pairwise comparisons were performed using Tukey’s test for ANOVA and Dunn’s test with Bonferroni correction for Kruskal-Wallis analyses. Two-group comparisons were conducted using the independent samples t-test or the Mann-Whitney U test, as appropriate. Categorical variables were analyzed using the chi-square test or Fisher’s exact test.

Exploratory binary logistic regression analyses were performed to evaluate factors associated with transfusion requirement and group discrimination. Given the observational design, these models were intended for hypothesis generation rather than causal inference. The discriminative performance of these models was assessed using receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) values. To evaluate sample adequacy, a post-hoc power analysis was conducted using one-way ANOVA with three groups. Assuming a medium effect size (Cohen’s f =0.25), an alpha level of 0.05, and the observed group sizes, the calculated statistical power was 0.9999. This analysis was performed to confirm sample adequacy rather than to guide study design. A p-value <0.05 was considered statistically significant.

Results

Baseline characteristics

The study cohort numbered 682 with 252 (36.95%), 178 (26.1%) and 252 (36.95%) women in Groups 1, 2 and 3, respectively.  Baseline demographic and obstetric characteristics are presented in Table 1. Statistically significant differences were observed between the three groups with respect to maternal age, gestational age at delivery, number of previous abortions, systolic blood pressure, diastolic blood pressure, and neonatal birth weight (all p<0.05). BMI, gravidity, parity, and neonatal birth length  were comparable across groups (p>0.05).

Preoperative hemoglobin level, hematocrit, platelet count, neutrophil count, and lymphocyte count did not differ significantly between the groups (Table 2). In contrast, postoperative hemoglobin level, hematocrit, and platelet count differed significantly among the three groups (Table 2).

Pairwise comparisons demonstrated no statistically significant difference in hemoglobin deficit between Group 1 and Group 2 (p=0.346). However, hemoglobin deficit was significantly greater in both Group 1 and Group 2 compared with Group 3 (p<0.05 for both comparisons) (Figure 1). Hematocrit deficit was significantly greater in Group 1 than in Group 2 and Group 3 (p<0.05 for both comparisons). Similarly, change in platelet count was significantly greater in Group 1 compared with both Group 2 and Group 3 (p<0.05) (Figure 2).

The rate of blood transfusion requirement differed significantly between the three groups (p<0.05), with the highest transfusion rate observed in Group 1. Length of hospital stay also differed significantly between groups (p<0.05). When analyzed according to transfusion status, patients who received transfusions had significantly longer hospital stays compared with those who did not in all three groups (all p<0.05). Group-specific hospitalization data stratified by transfusion status are presented in Table 3.

Neonatal outcomes are summarized in Table 4. A significant difference was observed in birth weight between the three groups (p<0.05). Pairwise comparisons revealed that birth weight was significantly lower in Group 2 compared with Group 1 (p<0.05) and Group 3 (p<0.05), whereas no significant difference was observed between Group 1 and Group 3 (p=0.956) (Table 5). No statistically significant differences were found between the groups with respect to neonatal birth length  or Apgar scores at 1 and 5 minutes (all p>0.05).

Among patients with uterine fibroids (Groups 1 and 2), myoma-related characteristics differed significantly between groups. Maximum myoma volume was significantly higher in Group 1, whereas myoma count was significantly higher in Group 2 (both p<0.05). Total myoma volume did not differ significantly between the two groups (p=0.09).

Subgroup analyses based on myoma number demonstrated that patients with multiple fibroids had significantly higher total myoma volume and maximum myoma volume compared with patients with a single fibroid (both p<0.05). In contrast, change in hemoglobin level, transfusion requirement rate, and length of hospital stay did not differ significantly between patients with single or multiple fibroids (all p>0.05). Neonatal outcomes, including birth weight and Apgar scores, were also comparable between the two subgroups (Supplementary Table 1).

The relationship between myoma count and perioperative outcomes is illustrated in Figure 3. Higher median hemoglobin change and longer hospital stay were observed across increasing myoma count categories. Transfusion rates also varied according to myoma count categories. Descriptive trends across myoma count groups are presented without formal statistical comparison.

When transfusion status was evaluated according to myoma burden, patients who received transfusions had higher total myoma volume and maximum myoma volume compared with those who did not. However, these differences did not reach statistical significance in pairwise analyses (Group 1: p=0.082; Group 2: p=0.210) (Table 6).

ROC analyses comparing patient groups demonstrated variable discriminative performance. The comparison between patients who underwent cesarean myomectomy and patients with fibroids who did not undergo myomectomy (Group 1 vs. Group 2) showed excellent discrimination (AUC =0.92). Comparisons between Group 1 and fibroid-free controls (Group 3) and between Group 2 and Group 3 demonstrated good discriminative performance, with AUC values of 0.81 and 0.82, respectively (Figure 4).

In a separate exploratory logistic regression model evaluating factors associated with the decision to perform myomectomy, limited discriminative ability was observed (AUC =0.602). The corresponding ROC curve is presented in Figure 5.

Discussion

The present study set out to provide a comprehensive comparison of maternal and neonatal outcomes among women undergoing CS with concomitant myomectomy, women with uterine fibroids managed conservatively at cesarean delivery, and women without fibroids. By employing a three-group design of 682 patients, our findings allow differentiation between the effects attributable to fibroid burden itself and those related specifically to the myomectomy procedure. Uterine fibroids may undergo variable changes in size during pregnancy. Recent evidence indicates that most fibroids either remain stable or increase only modestly in volume, particularly during the first trimester. Rapid fibroid enlargement is relatively uncommon and is often followed by stabilization or even regression later in pregnancy, likely due to changes in uterine blood flow and fibroid degeneration (4, 13).

Consistent with prior observational studies (10, 14), cesarean myomectomy in our cohort was associated with a greater magnitude of perioperative hematologic changes and higher transfusion rates compared with cesarean delivery in women without fibroids. However, a key finding of this study was that hemoglobin deficit did not differ significantly between patients undergoing cesarean myomectomy and those with fibroids who did not undergo myomectomy (p=0.346). This observation suggests that the presence of uterine fibroids, rather than the act of myomectomy itself, represents the dominant contributor to perioperative blood loss. This finding may partially be explained by impaired uterine contractility associated with fibroid-containing uteri. Fibroids can disrupt normal myometrial architecture and interfere with effective uterine contraction after delivery, thereby contributing to increased perioperative blood loss independent of myomectomy itself. In contrast, changes in hematocrit and platelet values were more pronounced in the cesarean myomectomy group. These findings likely reflect increased surgical manipulation and local hemostatic consumption associated with fibroid enucleation. Importantly, however, these laboratory differences did not translate into disproportionately higher rates of severe maternal morbidity, supporting the notion that cesarean myomectomy imposes an increased but clinically manageable hematologic burden when performed in appropriately selected patients.

The higher transfusion rate observed in the cesarean myomectomy group aligns with previous reports (6, 14), yet our subgroup analyses further clarify this relationship. Transfusion requirement was more closely related to postoperative hemoglobin levels and platelet counts than to fibroid number or total fibroid volume alone. On the other hand, some studies reported no significant difference in blood transfusion rates between women who underwent cesarean myomectomy and those who had cesarean delivery without myomectomy (15, 16). These findings suggest that, in appropriately selected patients and in experienced centers, cesarean myomectomy does not confer an additional transfusion risk compared with CS alone. In our study, hospitalization duration was significantly prolonged in transfused patients across all groups, underscoring transfusion status as a marker of postoperative recovery rather than a procedure-specific complication. Collectively, these findings further support the notion that perioperative blood loss is strongly influenced by the presence of uterine fibroids rather than the myomectomy procedure itself. Although cesarean myomectomy was associated with greater hematocrit and platelet changes, these likely reflect increased surgical manipulation and localized hemostatic consumption rather than uncontrolled hemorrhage. Importantly, no major myomectomy-related perioperative or postoperative complications, including puerperal sepsis or secondary postpartum hemorrhage, were observed in our cohort.

An important contribution of this study is the detailed evaluation of fibroid characteristics and their relationship to surgical decision-making. Patients undergoing cesarean myomectomy tended to have larger maximum fibroid volumes, whereas patients with fibroids managed conservatively more frequently exhibited a higher number of smaller fibroids. However, total fibroid volume did not differ significantly between these groups, suggesting that surgeons may prioritize accessibility and dominant lesion size over cumulative fibroid burden when deciding whether to perform myomectomy at the time of cesarean delivery. This approach is consistent with previous reports indicating that fibroid size and localization, rather than total fibroid load, play a central role in determining the feasibility and safety of cesarean myomectomy. Several studies have emphasized that larger, subserosal or pedunculated fibroids are more frequently selected for removal during cesarean delivery, whereas multiple smaller or intramural fibroids are often managed conservatively due to concerns regarding bleeding and operative complexity (16-18). Collectively, these findings support the concept that dominant fibroid characteristics, particularly size and surgical accessibility, are key determinants of intraoperative decision-making in cesarean myomectomy.

Subgroup analyses comparing single versus multiple fibroids further support this interpretation. Although patients with multiple fibroids had significantly higher total and maximum fibroid volumes, hemoglobin deficit, transfusion rate, and length of hospital stay were comparable between single and multiple fibroid subgroups. These findings imply that fibroid number alone may be a poor predictor of perioperative risk and that surgical feasibility is likely influenced by fibroid location, accessibility, and surgeon experience rather than numeric burden.

The exploratory logistic regression model evaluating factors associated with the decision to perform myomectomy demonstrated limited discriminative ability, reinforcing the complexity and individualized nature of intraoperative decision-making. Taken together, these results emphasize that cesarean myomectomy is not governed by a single quantitative threshold but rather by a constellation of anatomical and clinical considerations. In our institution, the decision to perform cesarean myomectomy was individualized and based primarily on intraoperative surgical assessment, including fibroid accessibility, dominant lesion size, technical feasibility, and perceived hemorrhage risk rather than predefined standardized criteria.

One of the most clinically relevant findings of this study relates to neonatal outcomes. Neonates born to mothers with fibroids who did not undergo myomectomy exhibited significantly lower birth weight compared with both cesarean myomectomy patients and fibroid-free controls. In contrast, birth weight did not differ between the cesarean myomectomy group and women without fibroids. Apgar scores and neonatal length were comparable across all groups. The significantly lower birth weight observed in patients with untreated fibroids suggests that the persistence of fibroids during pregnancy may negatively influence fetal growth. In contrast, birth weight in the cesarean myomectomy group was comparable to that of fibroid-free controls. Potential mechanisms include mechanical distortion of the uterine cavity and compromised uteroplacental perfusion. Fibroid localization may also influence neonatal outcomes. In particular, fibroids located near the lower uterine segment or uterine incision site may interfere with placental implantation, uterine distensibility, and local perfusion, potentially exerting a greater impact on fetal growth. These findings likely reflect the biological and mechanical effects of fibroids during pregnancy rather than the effect of cesarean delivery itself. However, fibroids directly involving the uterine incision site were not present in our cohort. Moreover, detailed localization data were not uniformly available in this retrospective study, limiting further subgroup analyses according to fibroid location. Notably, neonatal outcomes in the cesarean myomectomy group were comparable to those of fibroid-free patients, supporting the neonatal safety of myomectomy when performed under controlled conditions. These findings are consistent with previous studies reporting an association between untreated uterine fibroids and reduced neonatal birth weight, particularly in cases involving larger or strategically located fibroids (19, 20). Prior literature has suggested that fibroids may impair placental development and uteroplacental blood flow, thereby contributing to fetal growth restriction. Importantly, available evidence indicates that removal of selected fibroids at the time of cesarean delivery does not negatively affect neonatal outcomes, reinforcing the concept that cesarean myomectomy can mitigate fibroid-related growth impairment without compromising neonatal safety.

Recent systematic reviews and meta-analyses have increasingly challenged the traditional avoidance of cesarean myomectomy, reporting comparable rates of major maternal complications between cesarean myomectomy and cesarean delivery alone in selected populations. Our findings are concordant with this evolving body of evidence while adding nuance through the inclusion of a fibroid-positive non-myomectomy comparison group. This three-arm design highlights that fibroid presence itself constitutes a meaningful risk factor for both maternal hematological changes and neonatal growth restriction, independent of surgical intervention.

Study limitations

The strengths of this study include its large sample size, three-group comparative design, detailed assessment of hematological parameters, and comprehensive evaluation of fibroid characteristics. The inclusion of both maternal and neonatal outcomes provides a balanced assessment of perioperative safety and fetal well-being. Several limitations should be acknowledged. The retrospective nature of the study limits causal inference and introduces potential selection bias, particularly regarding the decision to perform myomectomy. Although major fibroid localization patterns were available, detailed standardized classification data for all fibroids, as well as surgeon-specific operative parameters including operative time and estimated blood loss, were not uniformly available. In addition, long-term maternal outcomes, such as fibroid recurrence and future fertility, could not be assessed. Finally, although neonatal outcomes were reassuring, long-term neonatal follow-up was beyond the scope of this analysis.

Despite these limitations, our findings contribute meaningful evidence to the ongoing debate surrounding cesarean myomectomy. Importantly, the heterogeneity of existing studies-particularly with respect to fibroid characteristics, surgeon experience, and institutional resources-has limited the development of universal guidelines. The results suggest that, in selected patients, cesarean myomectomy can be performed without compromising neonatal outcomes and without imposing disproportionate maternal risk beyond that associated with fibroid presence itself. These data support a shift from a uniformly conservative approach toward a more individualized, anatomy-driven surgical strategy. Our results support a more individualized approach, emphasizing patient selection, surgical expertise, and intraoperative assessment rather than categorical avoidance or endorsement of cesarean myomectomy.

Conclusion

Cesarean myomectomy appears to be a feasible and clinically acceptable option in selected patients when performed by experienced surgeons. The presence of uterine fibroids themselves may contribute more substantially to perioperative hematological changes and adverse neonatal growth outcomes than the myomectomy procedure itself. Future prospective studies with standardized reporting of fibroid characteristics, surgical techniques, and perioperative management are warranted to further refine patient selection criteria. Randomized trials may be challenging in this context but well-designed multicenter registries could provide high-quality evidence to guide clinical decision-making and inform guideline development.