During pregnancy, the accurate diagnosis of ureteric stones is masked by physiological changes. Clinical signs and symptoms, microscopic haematuria, and greyscale ultrasound can be used as primary modalities for diagnosis. The most common clinical presentation of ureteric stones in pregnant patients is loin pain. Andreoiu et al. in 2009 reported loin pain in 96.5% of 144 confirmed cases [11]. In our study, loin pain occurred in 22 patients (84.6%) in 26 confirmed cases; however, the clinical presentation of ureteric stones in pregnancy became less predictable for diagnosis, since loin pain and microscopic haematuria may occur as part of the ordinary course of pregnancy.
More stones on the right side are diagnosed because the physiologic hydronephrosis that is diagnosed by ultrasound more often on the right side raises the suspicion of ureteric stones and may miss left-sided stones because of bowel gas from the sigmoid colon.
In the acute presentation, grayscale ultrasound may miss ureteric stones, with a high false-negative rate but high sensitivity when there is clinical suspicion or radiological signs such as hydronephrosis exist. The sensitivity and specificity of ultrasonography for renal stone disease are 59%–78% and 100%, respectively [12].
Lifshitz DA et al. retrospectively analyzed ten symptomatic pregnant women who had ureteric stones that required URS in 2000. The mean patient age was 23 (range 17–31) years. Ultrasound scanning was performed in all patients and showed a low sensitivity (28.5%) when compared with intraoperative findings [13].
In our study, we used ultrasound as the primary modality for diagnosis and applied it to all patients. Stones yielded a positive result in 73.1% of patients, and 26.9% of patients with high clinical suspicion of ureteric stones were diagnosed during ureteroscopy.
Few ultrasonic parameters can help, such as using a transvaginal probe, monitoring the ureteric jet, and measuring the resistive index [14], and using colour Doppler for the assessment of the ureteral jet may assist in the diagnosis of ureteral obstruction [15]. Measuring the renal artery resistive index will facilitate the diagnosis of the obstruction [16].
Other modalities for diagnosis include MRI, low-dose CT scans (< 3.5 mSv), or ultralow-dose CT scans (< 1.9 mSv) [17]. The overall sensitivity of the diagnostic modalities of ultrasound, MRI, and CT for detecting ureteric stones during pregnancy is 77%, 80%, and 95.8%, respectively [18].
In 2001, Watterson et al. performed a retrospective analysis of eight patients with a total of 10 symptomatic ureteral calculi. They underwent URS with laser management. Stone access and complete fragmentation were achieved in all patients. The overall procedural success rate was 91%, with eight of nine calculi treated successfully (stone-free rate: 89%) [19]. Latina et al. performed a systematic review of the literature from January 1990 to June 2011 to evaluate the clinical efficacy and safety of ureteroscopy as a primary treatment for pregnant women with symptomatic ureteric stones. A total of 239 abstracts were screened, and 15 studies that reported on 116 procedures were identified. The complete stone clearance rate was 86%, with two major complications and seven minor complications [20]. A recent systematic review by Semins et al. clarified that 14 of 108 pregnant patients who underwent ureteroscopy stone treatment had an overall urological complication rate of 8.3%, with no significant differences in ureteral injury and urinary tract infection compared with nonpregnant women [21].
The mean operative time was higher among the flexible URS group (49.2 ± 5.84) versus the semi-rigid URS group (31.73 ± 3.19), which was explained by the fact that the handling and use of lithotripsy in a flexible device to target a stone is sensitive to respiratory movement, especially in patients under spinal anesthesia.
A retrospective study performed by Johnson EB et al. for assessing postoperative obstetrical complications in pregnant women who underwent ureteroscopy identified preterm labour in 2 of 46 patients at five institutions, with an overall obstetric complication rate of 4.3% [22].
In our study, the gestational period showed no significant differences between the groups. There were no preterm labor cases or major obstetric complications because our primary decision was to relieve obstruction, and difficult circumstances were postponed for a delayed operation.
In our study, the overall stone-free rate was 23 out of 26 (88.46%); the total success rate was 87%, with no significant difference in the mean operative time when the semi-rigid ureteroscope was used. The overall postoperative complications were classified as Clavien–Dindo grade 1 in 20 patients (76.9%), who had mild complications (loin pain, haematuria, nausea and vomiting, and stent-related symptoms) and as Clavien–Dindo grade 2 in 6 patients (23.07%), who had a postoperative fever. Ureteral injury with a Satava classification of G1 (ureteral injury without sequelae) occurred in 6 patients (23.55%).
Postoperative analgesia was used in 4 of 26 patients, which was significantly different between the groups and generally reflecting the success of endourology in pregnancy, which reduced the amount of analgesia needed after relieving the obstruction.
The American Urological Association (AUA) guidelines approve an initial conservative treatment with expected spontaneous stone passage [19]. Medical expulsive therapies (METs) such as alpha-blockers (tamsulosin) and calcium channel blockers (nifedipine) have no US Food and Drug Administration (FDA) approval for use during pregnancy [23].
Historically, the temporary modality has been considered the gold-standard management because it is less invasive and potentially useful in relieving obstruction and pain and maintaining optimal renal function [24, 25]. Active urinary tract infection or urosepsis is an absolute contraindication for definitive stone treatment. In our study, during active management, none of the cases had urosepsis on presentation; the proposed operation was employed to alleviate obstruction with a JJ stent, and it was intraoperatively decided that definitive treatment would proceed based on stone, kidney, and patient factors.
A more recent retrospective study performed by Abedi AR et al. reported the safety and efficacy of URS and laser lithotripsy in 15 pregnant women who had ureteral stones, and there were no significant complications; however, the authors noted the limitations of the study, such as the retrospective nature and the small sample size [26]. Overall, these studies do not provide clear evidence supporting the safety of ureteroscopy and anesthesia during pregnancy, and the lack of fluoroscopic control requires advanced surgical techniques and surgeon experience. The limitation of our study was the limited number of cases. Further investigations should be performed, and our study can be used as a reference.
