Don’t Hesitate on Performing Laparoscopic Surgery for Ovarian Masses during Pregnancy: A Multidisciplinary Approach to Ovarian Masses Complicating Pregnancy

The estimated incidence of ovarian masses during pregnancy is approximately 0.05% to 3.2%.1, 2 Recent advances in imaging techniques such as ultrasonography or magnetic resonance imaging have led to an increase in incidentally identified ovarian masses during pregnancy.3, 4

Treatments for ovarian masses detected during pregnancy include observation, aspiration, emergent surgery or elective surgery.5, 6, 7 Studies investigating ovarian masses during pregnancy recommend emergent surgery in the case of acute abdomen.8, 9 However, asymptomatic masses are analysed according to their size or potential malignancy before medical diagnosis or surgical intervention.10, 11

In case of elective surgeries, the operation is recommended between 16 and 23 weeks of gestation.2 In addition, laparoscopy and laparotomy are both known to be associated with similar risk of surgical complications.12, 13 According to the recent guidelines issued by the Society of American Gastrointestinal & Endoscopic Surgeons (SAGES), laparoscopy is recommended at any given gestation age.14, 15 However, laparoscopic surgery can be challenging in case of advanced gestational age.16

This study was performed to analyse the sonographic findings, mode of surgery, post-surgical outcomes, and neonatal outcomes of patients undergoing surgery for ovarian masses diagnosed during pregnancy.

This retrospective cohort study was performed at The Catholic University of Korea, Seoul St. Mary’s Hospital between 1st January 2009 and 31st December 2020. Patients with ultrasound diagnosis of ovarian masses during pregnancy were reviewed.

Patients were divided into 2 groups; those who underwent surgery for ovarian masses and those that received conservative care. The gestational age at the time of diagnosis in the 2 groups were compared along with the sonographic characteristics of the mass, surgical indications, method of surgery, intraoperative findings and pathological results. Sassone scoring, a scoring system that uses ultrasound to characterize ovarian lesion by calculating variables such as inner wall structure, wall thickness, septum and echogenicity, was evaluated.17 For those patients that gave birth in our hospital, obstetric and neonatal data were also analysed.

Laparoscopic surgery was conducted under general anesthesia. Fetal well-being was monitored via pre-operational and post-operational sonography to determine the fetal heart rate. Prophylactic antibiotics were administered before the operation. The patient was placed in supine, Trendelenburg position after anesthesia. The surgical bed was tilted to the contralateral side of the mass in order to ensure a better field of view during the operation. In addition, tilting to the opposite side prevented obstruction of the field of view from the enlarged pregnant uterus.

In general, a 10-mm trocar and a video laparoscope were inserted at the umbilicus. However, in patients over 20 weeks of gestational age, the trocar was inserted above the umbilicus to compensate for the height of fundus. The video laparoscope was inserted and the position of the uterus was confirmed to insert two 5-mm trocars without damaging the uterus. The insertion sites of these 2 trocars were determined based on the location of the mass. The ovarian mass ascertained via laparoscopy was treated via mass resection, oophorectomy, or detorsion, depending on the indicated diagnosis. The specimen was removed using an intraoperative bag. Post-operative pain control was achieved with acetaminophen or pethidine as needed. The patient was discharged on the post-operational day 2 and followed up at the outpatient clinic to continue with the general antenatal care.

Statistical analyses were performed using PASW Statistics ver. 18.0 (SPSS Inc., Chicago, IL, USA). Statistical significance was set at a P<0.05 (2-tailed). Categorical data are presented as number (%) and compared using chi-square test or Fisher exact test. Continuous variables are presented as mean±standard deviation. To assess independent predictors of surgery, we calculated odds ratios and 95% confidence intervals using logistic regression models.

As shown in Fig. 1, excluding patients who were lost to follow-up, a total of 114 pregnant females was diagnosed with concurrent ovarian masses. Of these patients, 82 (71.9%) were diagnosed in the first trimester of pregnancy and 49 (43.0%) underwent surgery for the ovarian mass during pregnancy. Out of 65 who did not undergo surgery during pregnancy, 50 (43.9%) were treated with concurrent ovarian mass excision at the time of cesarean section, and 10 (8.8%) experienced spontaneous regression of the mass after birth. The indication for surgery was torsion for 22 patients (44.9%), rupture for 2 patients (4.1%), increment in the size of mass for 13 patients (26.5%), and 12 others including pain, huge size and personal preference of patients. One patient was pathologically diagnosed with malignant ovary mass after operation.

Fig. 1
Enrollment, outcomes and follow-up of the study participants including indications for surgical treatment. ^a)Others: pain, huge size of mass, preference of patient.

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As shown in Table 1, the analysis of the group that underwent surgery for the ovarian mass antepartum revealed statistically significant difference depending on patients’ age, parity, body mass index before conception, and previous gynecologic operational history. Surgical intervention was performed in 87.8% of the patients with mass diagnosed at 1st trimester of pregnancy.

Table 1
Patient Demographics: Epidemiologic Characteristics between Surgical Treatment Group and Conservative Care Group

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As shown in Table 2, the mass of patients who underwent surgery antepartum was larger sonographically at the time of discovery and associated with a higher incidence of coexistent ascites. The most common pathology of ovarian mass in the group of patients treated surgically was either a simple mass or a cystadenoma (45.7%), followed by dermoid mass (37.0%) and endometrioma (15.2%). A single patient was diagnosed with a malignant ovarian mass.

Table 2
Sonographic and Pathologic Characteristics of Ovarian Mass of Surgically Treated and Medically Observed Group

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As shown in Table 3, the obstetric outcomes of patients that gave birth at our institution were assessed. No statistically significant differences were found in gestational age at the time of delivery in the groups of subjects who were treated with or without surgery during pregnancy (38.6 [37.3-40.2] weeks vs. 37.5 [35.4-41.0] weeks). Three of the patients that had surgery experienced miscarriages. In addition, fewer patients underwent cesarean section compared with those who were not operated for the ovarian mass.

Table 3
Obstetric Outcomes Compared between Surgically Treated Group and Medically Observed Group

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As for perinatal outcomes of neonates with patients that gave birth at our institution (Table 4), no significant differences in 1-minute or 5-minute Apgar score, meconium staining, fetal death in utero, or congenital anomalies were found between the 2 groups, whereas differences between fetal body weight were detected.

Table 4
Perinatal Outcomes Compared between Surgically Treated Group and Medically Observed Group

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A logistic regression analysis of risk factors revealed that younger age, earlier gestational age of ovarian mass detection, larger mass, and ascites increased risk of surgical treatment for ovarian mass during pregnancy (Table 5).

Table 5
Independent Risk Factors of the Patients Involved in the Study

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The rate of incidence of ovarian mass during pregnancy varies greatly depending on the author. Overall, rates are reported to be between 1.04% and 3.1% of pregnancies.1, 2, 13 This large variation is attributed to differences in the definition of clinically significant masses.10, 13 The majority of these masses involve corpus luteum or other functional masses that usually resolve by 16 weeks of gestation.16 Some ovarian masses persist, and 1% to 8% of these masses are pathologically diagnosed as malignant tumors.18 Most of the smaller masses resolve spontaneously.

Cases of ovarian masses found during pregnancy that cause complications that require emergent surgery can be found at any trimester of pregnancy.9 Indications of such complications include rupture, torsion and infection. This study found that surgical treatment was strongly indicated for ovarian masses of pregnancy if found at an earlier gestational age, have a larger size of mass, or was found to have concomitant ascites at the time of discovery.

Our findings suggest that the 2 groups showed no significant differences in obstetric or perinatal outcomes. Studies state a miscarriage rate of 10% to 20% in the general population, and our results also showed a similar rate of miscarriage.19 Although the results showed statistically significant differences in neonatal birthweight, the neonatal body weight average was much too high to be considered Intrauterine Growth Restriction (IUGR, 3.2 kg and 3.0 kg). Therefore, this does not reflect the possibility of IUGR in pregnancies undergoing surgical treatments.

Out of all patients that had surgery, one was diagnosed with malignancy. When she was first diagnosed with the ovarian mass at 6 weeks and 6 days’ gestation, the maximal diameter of the mass was 95 mm. Sonographically, the mass had no solid portions, locules, papillary projections, color flow, shadowing or ascites at the time of discovery. However, the mass showed mixed echogenicity and initial diagnostic impression was a hemorrhagic mass. A total score higher than 9 suggest malignancy and in this case total score was 7. The patient presented with aggravated lower right quadrant abdominal pain at 8 weeks and 5 days’ gestation and surgery was done as mass torsion was suspected. Laparoscopic operative findings included partially ruptured 10 cm right ovary mass with frozen biopsy result as malignancy. Laparoscopic right adnexectomy with both pelvic lymph node dissection and infracolic omentectomy was done and final pathology was malignant small round cell tumor, consistent with primitive neuroectodermal tumor of ovary with metastatic pelvic lymph nodes.

Our study has several limitations. The ovary is harder to locate during sonography if not detected during early gestational age as the uterus grows in size with progressive gestation.3 In turn, undiagnosed ovarian masses in the first trimester remained unnoticed during the entire pregnancy, underscoring the need for extra care in evaluating patients during early pregnancy for initial ovarian masses at the time of confirmation of pregnancy. In addition, the data were collected in a retrospective manner and no definite value of mass size was determined. The choice of operative intervention versus observation during pregnancy was made at each obstetrician’s decision.12 The study included patients treated over a 12-year time period. Significant improvements in ultrasound technology during this time may have influenced the management of patients.8 Color doppler imaging was not used consistently, and therefore its contribution to distinguishing malignant from benign masses in this population cannot be determined.

A notable finding from our study is that one malignant mass was diagnosed from pregnant patients with ovarian masses that underwent surgical intervention. As can be seen from our results, if surgery for ovarian mass during pregnancy has no adverse obstetric or perinatal outcomes, there should be no hesitation as to performing surgery on such pregnant patients. Additional care to include those oncologists and radiologic specialists should be given from the time of evaluation to those masses suspicious of malignancy.18

As for mode of surgery, laparoscopic surgery can still be a reasonable option even after first trimester. SAGES states that laparoscopic surgery can be performed at any gestational age of pregnancy.14, 15 However, when laparoscopic surgery is performed, much consideration as to placement of trocars in order to ensure a good field of view during the operation. In particular, patients with a gestational age above 20 weeks require additional care as the uterine fundus is located higher than the umbilicus.16 For each individual case, further discussion between an obstetric specialist and oncology specialist is needed to evaluate and treat ovarian masses found during pregnancy.18 In particular, extensive monitoring of fetal well-being before and after pregnancy is crucial for patients undergoing surgical excision of masses during pregnancy.

Our results show no statistically significant difference in obstetric and neonatal outcomes of those undergoing surgery during pregnancy for ovarian masses, and thus surgery during pregnancy for ovarian mass is safe and should be recommended as needed.