Comparison of the conservative approach with ureteral stent implantation in treating hydronephrosis during pregnancy

Meriç Balikoglu; Burak Bayraktar; Çagatay Özsoy; Ahkam Göksel Kanmaz; Mehmet Özeren

doi:10.4103/injms.injms_91_21

ORIGINAL ARTICLE

Year : 2022 | Volume : 13 | Issue : 1 | Page : 37-40

Comparison of the conservative approach with ureteral stent implantation in treating hydronephrosis during pregnancy

Meriç Balikoglu¹, Burak Bayraktar², Çagatay Özsoy³, Ahkam Göksel Kanmaz², Mehmet Özeren²
¹ Department of Obstetrics and Gynecology, Osmaniye State Hospital, Osmaniye, Turkey
² Department of Obstetrics and Gynecology, University of Health Sciences Tepecik Training and Research Hospital, Izmir, Turkey
³ Department of Urology, University of Health Sciences Antalya Training and Research Hospital, Antalya, Turkey

Date of Submission	08-Aug-2021
Date of Decision	19-Oct-2021
Date of Acceptance	19-Oct-2021
Date of Web Publication	19-Jan-2022

Correspondence Address:
Dr. Meriç Balikoglu
Akyar Area, Cross Over D400 Way, Osmaniye State Hospital, Osmaniye, Post Code: 80170
Turkey

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/injms.injms_91_21

Abstract

Objectives: Physiological and anatomical changes in the urinary system are expected in pregnancy. Therefore, uretero-hydronephrosis is observed in pregnant women in the second trimester. In this study, it was aimed to investigate the effect of ureteral double J stenting (DBJ) on perinatal outcomes and maternal urinary system values in order to decrease fetal and maternal morbidity of maternal hydronephrosis. Materials and Methods: Sixty-three pregnant women included in the study are split into two groups: 44 were administered conservative pain palliation (non-DBJ group/control) and 19 were implanted with a ureteral double J stent (DBJ group/case). Renal functions were evaluated using blood urea nitrogen (BUN) and creatinine levels. The presence of inflammation and infection was investigated using white blood cell (WBC) count, WBC in urine, nitrite presence, and growth in urine culture. The week hydronephrosis began and fetal birth weight and date were scanned. Results: There were no statistically significant difference between two groups leucocite, erythrocyte in urine, growth in urine culture, nitrite positivity indicated, and creatinine levels (P > 0.05, for all). BUN values were significantly lower in the DBJ group (P = 0.005). The prevalence of WBC in urine was statistically significantly higher in the DBJ group (P = 0.02). The week of birth was statistically significantly lower in the DBJ group than that in the non-DBJ group (36 ± 2 vs. 37.6 ± 3, P = 0.01). Conclusion: Our study suggests that implantation of a DBJ to patients who do not respond to conservative hydronephrosis treatment does not decrease the possibility of preterm birth and low birth weight.

Keywords: Etiology, flank pain, hydronephrosis, pregnancy, stents, therapy

How to cite this article:
Balikoglu M, Bayraktar B, Özsoy Ç, Kanmaz AG, Özeren M. Comparison of the conservative approach with ureteral stent implantation in treating hydronephrosis during pregnancy. Indian J Med Spec 2022;13:37-40

How to cite this URL:
Balikoglu M, Bayraktar B, Özsoy Ç, Kanmaz AG, Özeren M. Comparison of the conservative approach with ureteral stent implantation in treating hydronephrosis during pregnancy. Indian J Med Spec [serial online] 2022 [cited 2023 Mar 31];13:37-40. Available from: http://www.ijms.in/text.asp?2022/13/1/37/335975

Introduction

Urinary dilatation during pregnancy originates in the first trimester within physiological limits; however, it is noted in nearly 90% of pregnancies in the last trimester. It usually lasts for 6 weeks postpartum and shows spontaneous recovery. In the cases where physiological limits are exceeded, urinary dilatation manifests itself with side and groin pain due to hydronephrosis caused by urinary dilatation.^[1],[2] In the differential diagnosis of pregnant women presenting with groin pain and side pain, pregnancy-related complications such as preterm/term labor and placental abruption, along with maternal urolithiasis, pyelonephritis, appendicitis, ovarian cyst, and torsion, cholecystitis, and hydronephrosis should be considered during prediagnosis.^[3]

Physiological and anatomical changes in the urinary system are expected to occur during pregnancy. In addition to decreased intravascular oncotic pressure secondary to hypervolemia and hemodilution, increased renal vascular flow, and glomerular filtration rate, ureteral dilatation is observed due to the myorelaxant effect of progesterone – the predominant hormone in pregnancy – and the pressure on the ureters due to uterine enlargement during the second trimester. If this is left untreated, hydronephrosis develops eventually.^[4] Hydronephrosis in the left ureter is less common compared with that in the right ureter because the sigmoid column reduces the pressure of the uterus and fetus on the left ureter.^[5] Furthermore, urinary dilatation may increase if complications such as nephrolithiasis are accompanied with physiological changes occurring in the urinary system during pregnancy.^[6] Urinary ultrasonography (USG) may be required in such cases where differential diagnosis becomes challenging. The sensitivity and specificity of USG in identifying hydronephrosis are 83% and 91%, respectively.^[7]

Inflammatory processes, such as hydronephrosis, urinary tract infection, and nephrolithiasis, induced by urinary dilatation as well as surgical procedures that can be applied to the treatment may trigger preterm labor.^[8],[9],[10] Therefore, if hydronephrosis is detected during pregnancy, hydration, antispasmodics, nonsteroidal anti-inflammatory drugs, ureteral stenting, and nephrostomy applications should be performed effectively and in a timely manner in pregnant women to provide pain palliation and prevent the exacerbation of the inflammatory process to avoid preterm birth and reduce maternal–fetal morbidity.^{[2],[11],[12],[13]}

In this study, it was aimed to investigate the effect of ureteral double J stenting (DBJ) on perinatal outcomes and maternal urinary system values in order to decrease fetal and maternal morbidity of maternal hydronephrosis.

Materials and Methods

A total of 215 pregnant women who were admitted to the obstetric polyclinics of two different tertiary hospitals with groin and side pain between 2014 and 2017 and were diagnosed with hydronephrosis were included in the present study. The results of all pregnant women included in this study were retrospectively screened, and 63 pregnant women meeting the inclusion criteria were included in this study. Following the approval of the University of Health Sciences Tepecik Training and Research Hospital Ethics Committee, the study was initiated in accordance with the Helsinki Declaration principles.

Pregnant women included in this study were divided into two groups as case and control: 44 pregnant women with conservative pain palliation (non-DBJ group/control) and 19 pregnant women with ureteral double J stent placement after failure in conservative pain palliation (DBJ group/control). Demographic data, pregnancy outcomes, and the clinical variables of maternal urinary system were compared among the groups.

Women with singleton pregnancy, whose pregnancy follow-up was performed completely in line with the Ministry of Health protocols, and who underwent urinary USG for the differential diagnosis of groin pain and were diagnosed with hydronephrosis by a radiologist or urologist were included in this study. The pregnancy follow-up of pregnant women included in this study was retrospectively screened from the hospital information system, delivery room logs, and newborn examination logs, and pregnant women with missing data were excluded from the study. The exclusion criteria were multiple pregnancies, the previous diagnosis of hydronephrosis, being diagnosed with nonsymptomatic or incidental hydronephrosis during pregnancy, maternal congenital urinary anomaly, missing hospital records, and having given birth at centers out of the scope of this study.

In the pregnant women included in this study, hydronephrosis was graded according to renal calyx posterior–anterior diameters, major and minor calyx dilatation, and renal cortex thinning. Measurements were classified according to lateralization. Pregnant women without renal pelvis dilatation were classified as Grade 0, pregnant women with mild renal pelvis dilatation but without the dilatation of renal calyces and renal cortical thinning were classified as Grade 1, pregnant women with mild renal calyceal dilatation and moderate renal pelvis dilatation but without renal cortical thinning were classified as Grade 2, pregnant women with the dilatation of all renal calyces and renal pelvis while renal parenchyma was normal were classified as Grade 3, and pregnant women with the dilatation of renal calyces and renal pelvis accompanied with renal parenchymal thinning were classified as Grade 4.

Renal functions of the pregnant women included in the study were retrospectively evaluated using blood urea nitrogen (BUN) and creatinine levels in the 1^st week after the treatment. The presence of inflammation and infection was determined using white cell count, white and red cell counts and the presence of nitrite in urine, and growth in urine culture. If there were 5–10 white blood cells (WBCs) in urinalysis, it was defined 1+ WBC. If there were 10–15 WBCs in urinalysis it was defined 2+ WBC. If there were more than 15 WBCs it was defined 3+ WBC. The same classification was applied for red blood cell (RBC) in urinalysis. The pregnancy week of onset of hydronephrosis, birth weight, and birth time were obtained from hospital records.

Statistical analysis

Parametric variables were compared using independent samples t-test and presented as mean ± standard deviation. Chi-square and Fisher's exact tests were used for the comparison of categorical variables between the two groups, and the results were presented as n, %. IBM SPSS version 22.0 (Ill, Chicago) was used for statistical analysis. P < 0.05 was considered statistically significant.

Results

A total of 63 pregnant women with maternal urinary dilatation and pelvic pain were evaluated in two different groups as follows: non-DBJ group (n = 44) and DBJ group (n = 19). The demographic data and pregnancy outcomes of the pregnant women included in the study are summarized in [Table 1]. No statistically significant difference was noted between the groups in terms of maternal age, gestational week at the initial diagnosis of hydronephrosis, and creatinine values (P = 0.834, P = 0.733, and P = 0.786, respectively). BUN values were found to be below normal in both the groups, and BUN values were significantly lower in the DBJ group (P = 0.005).

Table 1: Demographic characteristics of participants

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Although the birth weight was lower in the DBJ group, no statistically significant difference was noted (P = 0.41). The gestational age at birth was significantly lower in the DBJ group compared with the non-DBJ group (36 ± 2 vs. 37.6 ± 3, P = 0.01). Urinary system examination and USG findings of the pregnant women included in the present study are summarized in [Table 2]. Although ureteral dilatation was observed more frequently on the right side in both the groups, right renal Grade 3 hydronephrosis was observed more frequently in the DBJ group (P < 0.001). Renal parenchymal echogenicity was increased in patients without DBJ stents, but there was no statistically significant difference between the two groups (P = 0.137 and P = 0.521, right and left parenchyma, respectively). No statistically significant difference was noted between the two groups in terms of WBCs, RBCs in urine, growth, and nitrite positivity in urinalysis (P = 0.908, P = 0.605, P = 0.589, and P = 0.449, respectively). However, the frequency of WBC presence in urine was significantly increased in the DBJ group (P = 0.02).

Table 2: Urinary ultrasonography and laboratory results of participants

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Discussion

The findings of the present study showed that DBJ placement in hydronephrosis during pregnancy does not reduce the risk of preterm delivery and low birth weight in patients who do not respond to conservative treatment.

During pregnancy, ureteral dilatation is observed at a speed of 0.5 mm/week until week 24–26 and at a speed of 0.3 mm/week until week 31–32 due to physiological reasons.^[14] Fetal weight, polyhydramnios, and large myomas, which affect intra-abdominal uterine weight during pregnancy, will indirectly affect the frequency and degree of hydronephrosis during pregnancy. However, the fact that hydronephrosis diagnosed in pregnancy does not resolve immediately after birth and continues until postpartum week 8 suggests that the effect of the ureteral pressure from the fetus on hydronephrosis is less than expected. The week when hydronephrosis is diagnosed in pregnant women included in our study corresponded to the end of the second trimester and the beginning of the third trimester, which was consistent with the literature.^[15],[16]

Although there was no statistical difference in WBC in the blood, stasis due to hydronephrosis that was not treated mechanically in the non-DBJ group increased the rate of WBC detection in the urine.

We believe that the higher frequency of preterm labor in the DBJ group with more advanced hydronephrosis grade is due to the fact that inflammatory and pain-related processes are more challenging to manage in this group compared with pregnant women receiving conservative treatment. It would not be incorrect to say that the mean birth weight was lower in the DBJ group because it was associated with an increase in the frequency of preterm labor and the inflammatory process.

Fainaru et al. applied a conservative approach in all cases in their study on 56 pregnant women with maternal hydronephrosis. Stent was applied to four patients who did not respond to treatment. They argue that the application of ureteral double J stent during pregnancy is safe and effective and has good perinatal outcomes and there is no preterm delivery.^[17]

Coban et al. classified 88 pregnant women with maternal hydronephrosis according to the grade of hydronephrosis and compared birth weight, creatinine value, and week of diagnosis among these groups. No difference was found between birth weight and creatinine value, and as in our study, it was found within normal limits. The diagnosis week was determined in parallel with the disease grade. DBJ stent was applied to only 2 of 88 patients, and pain palliation was achieved.^[18]

Similar to our study, the week diagnosed in the literature ranges from 26 to 29 weeks of gestation.^{[11],[15],[18]}

In a large-scale study with symptomatic 211 pregnant women with maternal hydronephrosis, conservative treatment was applied to all cases and ureteral stent treatment was applied to 80 cases who did not respond to treatment. An increase in C-reactive protein and WBC and more frequent preterm delivery were observed in the stent group.^[19]

Although the DBJ stent is safe and effective, several complications such as catheter migration, ascending pyelonephritis caused by vesicoureteral reflux, and stone formation may occur. While ureteral stenting causes regression of hydronephrosis, it does not guarantee its complete resolution.^[20]

The limited number of patients and the lack of postpartum follow-up can be considered as limitations of this study. Results can be biased as randomization could not be done for intervention due to the retrospective nature of the study.

The strength of our study is that all patients included in the study had symptomatic hydronephrosis and conservative options were tried as the first-line treatment. Furthermore, we believe that the presence of urinalysis, whole blood test, and urinary system USG for all patients further strengthens this retrospective study. Prospective randomized multicenter studies on this subject will help us establish standards on how to approach hydronephrosis in pregnancy.

Conclusion

The early diagnosis and initiation of treatment will protect the mother and the infant from numerous pregnancy-related morbidities that can lead to maternal organ damage, especially preterm labor. However, although DBJ placement helps us in preventing maternal complications due to hydronephrosis, as we can see in the present study, the strict follow-up of the patients for pregnancy complications is necessary.

Financial support and sponsorship

None.

Conflicts of interest

There are no conflicts of interest.

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