Urolithiasis in pregnancy. I: pathophysiology, fetal considerations and diagnosis

Has the COVID-19 pandemic affected ureteral stone management in pregnant women? A retrospective single-center study

INTRODUCTION

This study aimed to evaluate the effect of coronavirus disease (COVID-19) on the patients' referral in the pregnant population and also investigate each treatment approach's advantages and disadvantages for acute renal colic in pregnancy.

METHODS

In this retrospective study, we included all pregnant women with ureteral stones referred to a referral center between January 2019 and March 2021.

RESULTS

Among 53 pregnant women, 18 (33.9%) were on conservative therapy, which passed the stone without any complications. Double J stent or nephrostomy tube insertion was done for 24 patients (45.2%). Seventeen of these patients (70.8%) presented post-surgical complications, including hematuria (29.2%), pyelonephritis (20.8%), and lower urinary tract symptoms (20.8%). Transurethral lithotripsy (TUL) was done in 11 patients (20.7%). Only one of these patients developed hematuria following TUL. Thus, in our population study, double J stent or nephrostomy insertion was associated with a higher chance of postoperative complications than TUL (p-value = 0.001). Thirty-six patients were referred within 13 months before the entry of COVID-19, while 17 were referred during a similar approximate duration after the COVID-19 entry into the country. Only the initial presentation had a significant difference between these two periods (p-value = 0.034).

CONCLUSIONS

When conservative treatment fails, we recommend TUL as the second-line treatment over temporary procedures, such as double J stent or nephrostomy insertion. Of note, in a group of patients with an emergent clinical setting, including active infection, deteriorating renal function, signs of preterm labor, solitary kidney, etc., double J or nephrostomy tube insertion remains the preferred management method for its fast resolution of obstruction and infection. Besides, a decrease in visits with an increase in complicated cases after COVID-19 was observed, maybe due to a delay in referring.

Management of urolithiasis in pregnancy: A systematic review and meta-analysis

PURPOSE

Management of nephrolithiasis is unique in pregnancy and requires multidisciplinary care. To identify the effectiveness or safety of temporary drainage or definitive treatment methods to manage urolithiasis in pregnancy.

METHODS

The search strategy aimed to find both published and unpublished studies was conducted in August 2021. Studies published in any language on any date were considered for inclusion.

RESULTS

Of a total of 3349 publications, 36 studies were included in our qualitative evaluation and 32 studies in the quantitative synthesis. The commonly reported method was stent insertion (n = 29 studies), pneumatic (n = 12), laser (n = 9) lithotripsy, and stone removal using any devices (basket, grasper, or forceps) (n = 11). In seven studies, the authors reported the outcomes of conservative management, and the results showed that the stone-free rate is 54%, and symptom relief occurred in 62% of women. Seven eligible studies reported that 79.9% of urolithiasis were expulsed through stent insertion, while this rate was 94.6% among percutaneous nephrostomy use in two included studies, 88.5% for pneumatic lithotripsy (n = 7 studies), and 76.4% for laser lithotripsy (n = 4 studies), or 95.4% for stone removal method. In addition, adverse events were reported in less than 10% of pregnant women.

CONCLUSIONS

The results showed that stent, pneumatic or laser lithotripsy, and ureteroscopic stone removal were the commonest used methods in the included studies. They can be effective and safe treatment approaches without major maternal or neonatal complications, and could be introduced as an effective and safe therapeutic method for urolithiasis during pregnancy. However, most of the included studies had moderate quality according to critical appraisal checklists. Further prospective studies are needed to reach a conclusion.

Value of neutrophil-to-lymphocyte ratio in predicting surgical intervention for hydronephrosis during pregnancy

Background:

We aimed to examine the hematological parameters of pregnant patients with ureteral stones that require intervention.

Methods:

Medical data of patients presenting to urology department between October 2018 and December 2020 were retrospectively analyzed. Patients with flank pain associated with hydronephrosis were included in the study and divided into two groups according to whether an intervention was performed or not (Group-1, Group-2). Ureterorenoscopy (URS) or ureteral stent placement was performed as intervention. Demographic data, complete blood count (CBC), urine analysis, and ultrasonographic findings were collected. Gestational age (week), number of pregnancies, maternal age (years), Anteroposterior pelvis diameter (mm), VAS (Visual Analog Scale) (range 1–10) and mean platelet volume (MPV) were collected from the patient file. Inflammatory markers including neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were computed.

Results:

About 35 patients were included in Group-1 and 52 patients in Group-2. Ureterorenoscopy was performed in 21/35 (60%) patients, and ureteral stents were placed in 14/35 (40%) patients. None of the patients experienced complications. There was no statistical difference between these two groups in terms of maternal age, gestational age, number of pregnancies, pelvis diameter, PLR, and MPV. VAS and NLR were statistically higher in group-1 ( p < 0.05). According to the Receiver operating characteristic curve analysis performed for the prediction of ureteral stone presence, the best cut-off point for the NLR 4.153 (sensitivity 80%, specificity 80.6%, area under curve (AUC): 0.824).

Conclusions:

We think that NLR can be used to determine the group that needs to be intervented due to ureteral stones in patients with symptomatic hydronephrosis during pregnancy.

Outcomes of ureteroscopy and internal ureteral stent for pregnancy with urolithiasis: a systematic review and meta-analysis

Objectives

To investigate the outcomes of internal ureteral stents in comparison with ureteroscopy (URS) for pregnant women with urolithiasis.

Data sources

Relevant studies published from January 1980 to June 2022 were identified through systematic literature searches of MEDLINE, EMBASE, Web of Science and the Cochrane Library.

Methods of study selection

A total of 499 studies were initially identified. We included pregnant women in any stages of gestation who underwent double-J (D-J) stent insertion only or ureteroscopy for the treatment of urolithiasis; for a study to be included, the number of participants needed to exceed 10. This systematic review was registered on the PROSPERO website (Reference: CRD42020195607).

Results

A total of 25 studies were identified with 131 cases undergoing serial stenting and 789 cases undergoing URS. The pooled operative success rate was 97% for D-J stent insertion and 99% for URS. Only a few patients passed stones spontaneously after serial D-J stenting. The pooled stone free rate (SFR) in URS operations was about 91%. For internal ureteral stent therapy, the rate of normal fertility outcomes was 99%, although the pooled incidence of complications was approximately 45%. For group receiving URS treatment, the rate of normal fertility outcome was 99% and the pooled incidence of complications was approximately 1%. However, the pooled rate of premature birth and abortion were the similar between the two groups (< 1%); the rate of serious complications was also similar between the two groups.

Conclusions

Although internal ureteral stents may cause more minor complications, both ureteroscopy and internal ureteral stents showed had low rates of adverse effects on fertility outcomes when used to treat pregnant women with symptomatic urolithiasis. Evidence suggests that URS may have a greater advantage for pregnant patients with urinary stones when conditions permit. Since, it has been proven to be safe and effective, internal ureteral stents could be considered in emergency or other special situations.

Catastrophic complications of urolithiasis in pregnancy

Urolithiasis is the most common non-obstetric complication in pregnancy and has the potential to cause grave consequences resulting in pregnancy loss. We present two such cases. First, a 24-year-old woman, 5 weeks pregnant with a history of urolithiasis presented with right flank pain and fever. She was found to have a right perinephric collection and during the course of her treatment suffered an abortion. The second case was a 25-year-old woman who presented in septic shock. She underwent emergency lower segment caesarean section elsewhere 10 days ago for intrauterine death at 38 weeks of gestation. On evaluation, she was found to have bilateral stone disease with a left subcapsular haematoma. Both the cases were managed conservatively and are planned for definitive management. Thus, women of childbearing age with diagnosed urolithiasis should get themselves evaluated and be free of stone disease before planning a family to prevent increased obstetric complications during pregnancy.

Management of ureteric stone in pregnancy: a review

Background

Urolithiasis in pregnancy is a major health concern and is one of the most common causes for non-obstetrical abdominal pain and subsequent hospital admission during pregnancy. The incidence of urinary calculi during pregnancy varies in the range of 1/200 to 1/2000. Acute ureteric colic in pregnancy is associated with significant potential risks to both mother and fetus. Significant anatomic and functional changes occur in pregnancy which not only lead to stone formation but also create diagnostic dilemma. The diagnosis of ureteric calculi can be incorrect in about 28% of pregnant patients.

Main body

Management of ureteric stone during pregnancy is remaining to be a challenge for the treating urologist. Because of the inability to use good imaging options for the diagnosis confirmation and more invasive approach for the treatment, management continues to be difficult. The main threats are preterm labor with delivery and premature rupture of membranes. Other pregnancy complications are obstructive uropathy, gestational diabetes mellitus, recurrent abortions and pre-eclampsia. Management of diagnosed ureteric stone is unique in the pregnant population and requires multi-disciplinary care. It should be individualized for each patient and moves preferably from conservative to invasive approaches sequentially. With continued advancements in endourological techniques, few definitive treatment options are also available for such patients.

Conclusion

There are several lacunae related with the diagnostic imaging, medical expulsive therapy, reliability of ureteral stent/percutaneous nephrostomy insertions and safety of ureteroscopy during pregnancy. Herein, we review the management of ureteric stone during pregnancy, the various diagnostic modalities and treatment options with their advantages and disadvantages. We also proposed our management algorithm to deal with such clinical scenario in this particular population.

The comparation of effects and security of double-J stent retention and ureteroscopy lithotripsy in the treatment of symptomatic ureteral calculi during pregnancy

OBJECTIVE

To describe the efficacy of double-J stent retention and ureteroscopy lithotripsy, we performed a study to evaluate the management of symptomatic ureteral calculi during pregnancy.

MATERIALS AND METHODS

From January 2005 and June 2015, 53 pregnant women with symptomatic ureteral calculi were admitted and treated in our hospital. According to the treatment techniques, there were divided into two groups: double-J stent retention group (30 cases) and ureteroscopy lithotripsy group (23 cases). We collected the characteristics and treatment outcome of the patients.

RESULTS

Double-J stent retention was performed on 30 patients. And the stents were successfully inserted in 25 patients (83.3%). 4 cases got complication in double-J group (16%). The mean operating time, medical cost and hospitalization time of double-J group were 20.6 min, 1632 yuan and 1.3 days. Ureteroscopy lithotripsy was performed on 23 patients. 20 patients were operated successfully (87.0%). 2 cases got complication in ureteroscopy group (10.0%). The mean operating time, medical cost and hospitalization time of ureteroscopy group were 41.5 min, 2792 yuan and 6.0 days.

CONCLUSION

In summary, both double-J stent retention and ureteroscopy lithotripsy are effective and safe in the managation of ureteral calculi during pregnancy.

Stones in pregnancy and pediatrics

Urinary stone disease is a highly prevalent condition affecting approximately 10% of the population, and has increased in incidence significantly over the past 20 years. Along with this, the rate of stone disease among women and children is also on the rise. The management of stone disease in specific populations, such as in children and during pregnancy can present unique challenges to the urologist. In both populations, a multi-disciplinary approach is strongly recommended given the complexities of the patients. Prompt and accurate diagnosis requires a high degree of suspicion and judicious use of diagnostic imaging given the higher risks of radiation exposure. In general, management proceeds from conservative to more invasive approaches and must be individualized to the patient with careful consideration of the potential adverse effects. However, innovations in endourologic equipment and techniques have allowed for the wider application of surgical stone treatment in these patients, and significant advancement in the field. This review covers the history and current advances in the diagnosis and management of stone disease in pregnant and pediatric populations. It is paramount for the urologist to understand the complexities of properly managing stones in these patients in order to maximize treatment efficacy, while minimizing complications and morbidity.

Contemporary best practice urolithiasis in pregnancy

Urolithiasis is the most common nonobstetric complication in the gravid patient. The experience can provoke undue stress for the mother, fetus, and management team. The physiologic changes of pregnancy render the physical exam and imaging studies less reliable than in the typical patient. Diagnosis is further complicated by the need for careful selection of imaging modality in order to maximize diagnostic utility and minimize obstetric risk to the mother and ionizing radiation exposure to the fetus. Ultrasound remains the first-line diagnostic imaging modality in this group, but other options are available if results are inconclusive. A trial of conservative management is uniformly recommended. In patients who fail spontaneous stone passage, treatment may be temporizing or definitive. While temporizing treatments have classically been deemed the gold standard, ureteroscopic stone removal is now acknowledged as a safe and highly effective definitive treatment approach. Ultimately, a multidisciplinary, team-based approach involving the patient, her obstetrician, urologist, radiologist, and anesthesiologist is needed to devise a maximally beneficial management plan.

Review on diagnosis and management of urolithiasis in pregnancy: an ESUT practical guide for urologists

PURPOSE

Management of urolithiasis in pregnancy can be challenging for most urologists with diagnostic and treatment dilemma to ensure the best outcome for both mother and fetus. We wanted to review the literature for urolithiasis in pregnancy with a practical management guide for urologists.

METHODS

A non-systematic review of literature was carried out for all English language literature using Medline. To ensure a more comprehensive search, the review of diagnosis and management of pregnant patients with urolithiasis was carried out separately, by two authors independently. Due to diagnostic complexity, investigations (US, CT, MRI) carried out were assessed separately.

RESULTS

Our search included diagnostic studies such as US, CT and MRI (73, 20 and 27 articles, respectively) and management studies (55 articles in total). Details on etiology, radiation risk, safety of various diagnostic modalities, medications and treatment options are covered through an evidence-based approach. We provide a practical guide for urologists in what is clearly a stressful situation for patient and physician alike.

CONCLUSIONS

Urolithiasis in pregnancy needs a careful multidisciplinary management to achieve good outcomes for both mother and baby. Our review shows that a balanced approach for diagnosis and treatment seems to achieve the best outcomes in pregnancy.

Stones in special situations

There are several special situations in which urinary lithiasis presents management challenges to the urologist. An in-depth knowledge of the pathophysiology, unique anatomy, and treatment options is crucial in order to maintain good health in these patients. In this review, we summarize the current literature on the management of the following scenarios: bladder stones, stones in bowel disease, during pregnancy, in association with renal anomalies, with skeletal deformities, in urinary diversions, and in children.

Urolithiasis in pregnancy

Clinicians are faced with multiple diagnostic and treatment challenges when managing pregnant women with urolithiasis. Anatomical and physiological changes during pregnancy have to be taken into account whilst simultaneously considering both the expectant mother and the foetus. Ultrasonography remains the first-choice imaging modality, notwithstanding its potentially poor diagnostic accuracy. There is currently no consensus on second-line investigation for suspected urolithiasis. Low-dose non-contrast CT is highly sensitive, but the long-term effects of ionizing radiation on the foetus remain unknown. As far as treatment is concerned, expectant therapy is the primary option for management in the majority of cases. Percutaneous nephrostomy or ureteric stent placements are safe temporizing measures in relieving an acutely obstructed system and should be expedited in the presence of sepsis. Studies have shown ureteroscopy to be safe and effective during pregnancy with no significant risk to the foetus. It is important for the clinician to explain clearly the risks associated with the investigation and management options to the pregnant patient, including an acknowledgement that some of these remain unquantified, or even unknown.

Renal colic during pregnancy: Diagnostic and therapeutic aspects. Literature review

Introduction

Renal colic during pregnancy is a rare urgency but is one of the most common non-obstetric reasons for hospital admission. The management often means a challenge for the urologist and gynecologist due to the complexity involved in preserving the maternal and fetal well-being.

Material and methods

We performed a literature search within the PubMed database. We found 65 related articles in English. We selected 36 for this review prioritizing publications in the last two decades.

Results

The anatomical and functional changes of the genitourinary system during pregnancy are well documented; also during pregnancy, there are several metabolic pro-lithogenic factors. The most common clinical presentation is flank pain accompanied by micro or macro hematuria. US provides data identifying renal obstruction shown by an increased renal resistance index. MRI allows differentiating the physiological dilatation from the pathological caused by an obstructive stone showing peripheral renal edema and renal enlargement. Low dose CT has been determined to be a safe and highly accurate imaging technique. Once the diagnosis is confirmed, the initial management of patients should be conservative. When conservative management fails the interventional treatment is mandatory, a urinary diversion of the obstructed renal unit either by a JJ stent or through a PCN catheter has to be done. The definitive management of the stone can be done in the postpartum or deferred ureteroscopy can be considered during pregnancy.

Conclusions

Renal colic during pregnancy is an uncommon urgency, so it is important for the urologist to know the management of this condition.

Our ultrasonographic experience in the management of symptomatic hydronephrosis during pregnancy

INTRODUCTION

The aim of the present study was to document the role of ultrasound in the diagnosis and management of symptomatic hydronephrosis during pregnancy.

METHODS

In this study, we reviewed 36 consecutive cases of pregnant women whose pregnancy was complicated by symptomatic hydronephrosis. In all patients, management was initially conservative (analgesics and fluids) after hospitalization. The following criteria were used to indicate double-J stent placement under US guidance rather than a conservative treatment: persistent pain with no improvement after conservative treatment, progressive hydronephrosis (>2 cm dilatation of the renal pelvis) or presence of uterine contractions.

RESULTS

The mean patient's age was 25 years (17-35) and gestational age at clinical presentation was 24 weeks (13-37). 81 % of cases had a renal pelvis dilatation >2 cm, while in only 19 % of cases there was a hydronephrosis between 1 and 2 cm in diameter; however, calculi were confirmed only in 25 patients. 28 patients required an invasive management with double-J stent insertion under US guidance. The sensitivity and specificity of US in the etiological diagnosis of hydronephrosis during pregnancy was 83 and 91 %, respectively.

CONCLUSION

Conservative management with medical therapy and observation should be the first-line treatment approach. In our opinion a rapid ureteral decompression with the insertion of a ureteral double-J stent, under US visualization, is the safest method in the treatment of pregnant women with obstructed renal systems.

Stone disease in pregnancy: imaging-guided therapy

Renal colic is the most frequent nonobstetric cause for abdominal pain and subsequent hospitalization during pregnancy. The physio-anatomical changes in the urinary tract and the presence of the fetus may complicate the clinical presentation and management of nephrolithiasis. Ultrasound (US) is the primary radiological investigation of choice. Magnetic resonance urography (MRU) and low-dose computed tomography (CT) have to be considered as a second- and third-line test, respectively. If a study that uses ionizing radiation has to be performed, the radiation dose to the fetus should be as low as possible. The initial management of symptomatic ureteric stones is conservative during pregnancy. Intervention will be necessary in patients who do not respond to conservative measures. Therefore, it is crucial to obtain a prompt and accurate diagnosis to optimize the management of these patients. Teaching Points • In pregnancy, renal colic is the most frequent nonobstetric cause for abdominal pain and hospitalization. • Magnetic resonance urography should be considered when ultrasound is nondiagnostic. • Low-dose CT should be considered as a last-line test during pregnancy.

Current status of ureteroscopy for stone disease in pregnancy

Ureteroscopic management of urolithiasis in pregnancy has been on the rise. Technological advancements such as the development of the semi-rigid or flexible ureteroscope, improvements in the design of baskets used for retrieval and the availability of laser have enabled atraumatic fragmentation of stones. We did a systematic review of literature from January 1990 to December 2012. Data were analysed separately for the time period from January 1990 to June 2010 (Period 1) and for last 2.5 years from July 2010 to December 2012 (Period 2). Inclusion criteria were all English language articles with at least three patients reported. Data were extracted on the outcomes and complications reported in the literature. A total of 271 procedures (116 in period 1, 155 in period 2) across 21 studies were reported in the last 22 years. General anaesthesia was used in 38% (44/116) in period 1 and in 64% (99/155) in period 2. The average stone size (7.6 mm) and stone-free rate (SFR) (85%) were similar in both time periods. Fluoroscopy was used in 20% (23/116) and 24% (38/155) in period 1 and 2, respectively. There were fewer complications in period 1 (n = 9) than period 2 (n = 25). These complications were divided into obstetric (n = 5) and non-obstetric complications (n = 29). There were no maternal or foetal deaths during the 22 years. Stone treatment using ureteroscopic techniques in pregnancy can achieve a high success rate. Evidence suggests a rise in the risk of complications with increasing number of these procedures in pregnancy.

Challenges on percutaneous nephrolithotomy in pregnancy: Supine position approach through ultrasound guidance

Urolithiasis in pregnancy represents a major diagnostic and therapeutic challenge to the obstetrician, urologist, radiologist and anesthetist. It is a cause of major concern, considering the potential adverse effects of radiation exposure and of any invasive surgical procedure and anesthesia on the mother and fetus. Fortunately, with conservative management, 70-80% of symptomatic calculi pass spontaneously with no sequel. However, fever, infection, uncontrolled pain and progressive hydronephrosis are indications for surgical intervention when retrograde placements of a ureteral stent or a percutaneous nephrostomy tube are the most traditional options. The recent technological advances in stone fragmentation devices and the administration of safe anesthesia have forced clinicians to embark on more definitive stone management techniques in pregnancy. Ureteroscopy is considered the first definitive treatment of obstructive ureteral calculi during all trimesters of pregnancy, but also has limitations. Although generally avoided during pregnancy, percutaneous nephrolithotomy can be a good treatment choice in selected patients.

Outcomes of ureteroscopy for stone disease in pregnancy: results from a systematic review of the literature

INTRODUCTION

Our aim was to evaluate the clinical efficacy and safety of ureteroscopy as a primary treatment for pregnant women with symptomatic ureteric stones who have failed conservative management.

MATERIALS AND METHODS

A systematic review of the literature from January 1990 to June 2011 was performed, including all English language articles. Outcome measures were clinical efficacy, in terms of stone clearance and need for additional procedures, and safety in terms of complications.

RESULTS

A total of 239 abstracts were screened and 15 studies were identified reporting on 116 procedures. The surgical methods of stone management employed were stone extraction with basket only (n = 55, 47%), laser fragmentation (n = 27, 23%; holmium, n = 20, pulse dye, n = 7), impact lithotripsy (n = 21, 18%), ureteroscopic lithotripsy (n = 6, 5%) and a combination of methods (n = 6, 5%). A post-operative stent was inserted in 64 of 116 procedures (55%). Complete stone clearance was seen in 100 of the 116 procedures (86%). There were 2 major complications (1 ureteral perforation and 1 case of premature uterine contraction) and 7 minor complications (5 urinary tract infections and 2 cases of post-operative pain).

CONCLUSION

This review suggests that stone clearance using ureteroscopy is a relatively safe option in pregnancy with a high success rate.

Experience with the diagnosis and management of symptomatic ureteric stones during pregnancy

OBJECTIVE

To present our experience to describe diagnosis and management of symptomatic ureteric stones during pregnancy.

MATERIALS AND METHODS

Thirty-six pregnant women with symptomatic ureteric stones were evaluated in this study. The diagnosis was done by history, physical examination, symptoms, signs, ultrasonography, or ureteroscopy if needed. Initially, conservative management was performed on all patients. When conservative treatment failed, temporizing therapies (double-J stenting or percutaneous nephrostomy [PCN]) and (ureteroscopic lithotripsy) URSL were performed on the patients.

RESULTS

In 25 (69.4%) of the patients, ureteric stones was diagnosed on US. In the other 11 (30.6%) of the patients, definitive diagnosis was done by ureteroscopy in 5, and 6 of them passed their stones spontaneously. Conservative management was successful in 24 of 36 (66.6%) the patients. Temporizing therapies and URSL were required in 12 of 36 (33.4%) patients. A double-J stent was successfully placed in only 3 (8.3%) of the patients, and URSL was performed in 9 (25%). In 1 (2.7%) patient, PCN was performed because of persistent renal colic, fever, and pyonephrosis. In this patient, URSL was performed after symptoms and signs resolved, and then the percutaneous tube was removed.

CONCLUSION

If ultrasonography fails, ureteroscopy may be an alternative approach for definitive diagnosis. When conservative approach fails, URSL may be a good alternative approach for definitive treatment.

Urologic emergencies in pregnancy

The management of urological emergencies during pregnancy presents unique clinical challenges for the treating physician. Clinical signs and symptoms are often subtle while diagnostic and therapeutic options are limited in treating patients to avoid fetal morbidity. A high index of suspicion with early diagnosis and treatment are essential for the management of genitourologic emergencies in pregnant women. It is essential for patients to be managed on an individual basis using a multidisciplinary approach.

Stone formation and pregnancy: pathophysiological insights gained from morphoconstitutional stone analysis

PURPOSE

We examined whether stone composition in pregnant women reflects peculiar pathophysiological conditions.

MATERIALS AND METHODS

We analyzed in detail the composition of stones from 244 pregnant women 17 to 44 years old and from 5,712 nonpregnant women in the same age range, as recorded between January 1991 and December 2007. Clinical features were also recorded. All stones were analyzed by morphological examination coupled with infrared spectroscopy. The 2 patient groups were compared by clinical and biochemical characteristics.

RESULTS

Stone episodes in pregnant women manifested mainly in trimesters 2 and 3 (39% and 46%, respectively). Spontaneous passage was noted in 81% of pregnant vs 47% of nonpregnant women (p <0.0001). Calcium phosphate, mainly in the form of carbapatite, was the main stone component in 65.6% of pregnant vs 31.4% of nonpregnant women (p <0.0001). Octacalcium phosphate pentahydrate, a transition phase in calcium phosphate stone formation, was found in a 5-fold higher proportion in carbapatite stones in pregnant than in nonpregnant women, a finding also suggesting recent stone formation during pregnancy.

CONCLUSIONS

The composition of stones manifesting during pregnancy clearly differs from that of stones formed in nonpregnant women of childbearing age, suggesting a different pathophysiology specific to the pregnant state. In view of the pH dependency of calcium phosphate stones factors that increase the physiological elevation in maternal urinary calcium excretion and pH are likely to have a role in the preferential formation of calcium phosphate stones during pregnancy.

Semirigid ureteroscopy and pneumatic lithotripsy as definitive management of obstructive ureteral calculi during pregnancy

OBJECTIVES

To assess the results of semirigid ureteroscopy and intracorporeal pneumatic lithotripsy as a definitive treatment option for women presenting with obstructive ureteral calculi during pregnancy.

METHODS

A retrospective analysis was performed of 19 pregnant patients referred to our tertiary care center with ureteral obstruction necessitating surgical intervention from 1997 to 2007. The mean patient age was 22 years (range 18-27), and the mean gestation period was 20 weeks (range 14-34). Of the 19 patients, 21% were febrile, 32% had positive urine cultures, and 63% had pyuria and microscopic hematuria. Abdominal ultrasonography was the principle diagnostic test used. Six patients had history of renal stones before conception. The mean stone size was 11 mm, (range 8-18). Of the 19 patients, 58% had stones located in the proximal and 42% in the distal ureter. The stones were fragmented using a Swiss pneumatic lithoclast through a 6.9F/8F semirigid ureteroscope with the patient under general anesthesia. None of the patients underwent limited intravenous urography or computed tomography except for 1, who underwent plain x-ray of the kidneys, ureters, and bladder.

RESULTS

All patients had obstruction due to the ureteral calculi, and 79% patients had complete fragmentation of the calculi by ureteroscopy as the primary treatment. Of the 19 patients, 63% required ureteral stent insertion per operatively. No complications related to the procedure itself or the general anesthesia were recorded, and all patients completed the full term of pregnancy.

CONCLUSIONS

The results of our study have shown that semirigid ureteroscopy to diagnose ureteral calculi and treat them with intracorporeal pneumatic lithotripsy and ureteral stent insertion, as indicated, is the most efficient and definitive treatment modality in expectant women.

Urinary Stone Disease during Pregnancy: One Problem, Two Patients

Urolithiasis in pregnant women is a quite uncommon event: about one in 1500 pregnancies is complicated by urinary calculi and it occurs in 80–90% of the patients during the second or third trimester of pregnancy.

Several factors may predispose stone formation in the upper urinary tract during pregnancy: the “physiological” hydronephrosis, the gestational hypercalciuria, and an elevation in both glomerular filtration rate and renal plasma flow, associated with an increase of creatinine clearance and higher renal filtration rate of sodium, calcium, and uric acid. Flank or abdominal pain is the most common symptom associated with evident or microscopic hematuria. Differential diagnosis of pain varies according to its location: it could be of gastrointestinal or gynecologic origin.

Diagnosis is previously based on ultrasound evaluation. The use of radiation must be avoided during pregnancy, even if the risk of fetal injures depends on gestational age and radiation dosage. Most of the symptomatic ureteral stones affecting pregnant women pass spontaneously: therefore therapy could be conservative (hydration, analgesia, antibiotics, antiemetics) in the most of cases, although in the 15–30% of the cases it is necessary to adopt an active treatment, like percutaneous nephrostomy drainage, ureteral stent insertion or ureterorenoscopy.

Management of urinary calculi in pregnancy: a review

Nephrolithiasis during pregnancy can represent a clinical dilemma because of potential risks to both mother and fetus. While the incidence of symptomatic nephrolithiasis during pregnancy varies between 1 in 244 to 1 in 2000 pregnancies, the actual incidence is likely to be higher. A significant proportion of patients with asymptomatic renal calculi are detected incidentally in the nonpregnant population compared with pregnant women. Factors that contribute to the diagnostic challenges include anatomic and physiologic changes to the female urinary tract during pregnancy and the limitations on the use of ionizing radiation. The treatment of such patients requires a multidisciplinary team approach involving the urologist, obstetrician, and radiologist. The potential hazards of intervention (either surgical or medical) and anesthesia need to be considered carefully.

Imaging modalities for urolithiasis: impact on management

PURPOSE OF REVIEW

Urolithiasis is a common urological problem, often requiring efficient workup, accurate diagnosis, and treatment. The purpose of this review is to summarize the imaging modalities employed for the diagnosis of calculi and the caveats of different clinical situations.

RECENT FINDINGS

Noncontrast computed tomography has become the most universally used imaging tool for diagnosing urolithiasis, although ultrasound and magnetic resonance imaging maintain specific roles. Noncontrast computed tomography may provide prognostic information regarding the success of specific management strategies for urolithiasis. Additionally, noncontrast computed tomography is being tested in lower-radiation dose protocols with promising results.

SUMMARY

Considering the well supported accuracy and relative ease of use of noncontrast computed tomography, it has become a logical choice for the urologist to use the technique as a diagnostic tool for stone disease. The future of imaging for intervention and surveillance of stone disease lies in the continued progress of noncontrast computed tomography in terms of patient safety. This will need to be done by developing low-dose radiation computed tomography that can replicate the efficacy of current noncontrast computed tomography.

Giant intravesical calculus during pregnancy

Urolithiasis is commonly found during pregnancy; but the presence of a giant vesical calculus during pregnancy is a very rare entity, associated with several potential obstetric complications. A 25-year-old primigravida at 25 weeks of gestational age was referred to our tertiary care unit because she presented a giant hyperechoic intravesical mass and inability to pass urine with suprapubic pain since 2 days. An open cystolithotomy revealed a huge intravesical calculus. The patient continued with her pregnancy until full term without adverse perinatal outcomes.

Imaging the pregnant patient for nonobstetric conditions: algorithms and radiation dose considerations

Use of diagnostic imaging studies for evaluation of pregnant patients with medical conditions not related to pregnancy poses a persistent and recurring dilemma. Although a theoretical risk of carcinogenesis exists, there are no known risks for development of congenital malformations or mental retardation in a fetus exposed to ionizing radiation at the levels typically used for diagnostic imaging. An understanding of the effects of ionizing radiation on the fetus at different gestational stages and the estimated exposure dose received by the fetus from various imaging modalities facilitates appropriate choices for diagnostic imaging of pregnant patients with nonobstetric conditions. Other aspects of imaging besides radiation (ie, contrast agents) also carry potential for fetal injury and must be taken into consideration. Imaging algorithms based on a review of the current literature have been developed for specific nonobstetric conditions: pulmonary embolism, acute appendicitis, urolithiasis, biliary disease, and trauma. Imaging modalities that do not use ionizing radiation (ie, ultrasonography and magnetic resonance imaging) are preferred for pregnant patients. If ionizing radiation is used, one must adhere to the principle of using a dose that is as low as reasonably achievable after a discussion of risks versus benefits with the patient.

Admission for Nephrolithiasis in Pregnancy and Risk of Adverse Birth Outcomes

OBJECTIVE

Nephrolithiasis occurring during pregnancy may be associated with an elevated risk of preterm delivery and other adverse birth outcomes. The goal of this study was to describe the association between these outcomes and admission for nephrolithiasis during pregnancy.

METHODS

We performed a retrospective cohort study using birth certificate records linked to Washington State hospital discharge data from 1987-2003 to compare pregnant women admitted for nephrolithiasis and randomly selected pregnant women without nephrolithiasis. The main outcomes of interest were preterm delivery, premature rupture of membranes at term or before 37 weeks of gestation, low birth weight, and infant death.

RESULTS

A total of 2,239 women were admitted for nephrolithiasis, yielding a cumulative incidence of 1.7 admissions per 1,000 deliveries. Women admitted for nephrolithiasis during pregnancy had nearly double the risk of preterm delivery compared with women without stones (adjusted odds ratio 1.8, 95% confidence interval 1.5-2.1). However, they were not at higher risk for the other outcomes investigated. A total of 471 (25.9%) women had one or more procedures for kidney stones during prenatal hospitalization. Undergoing a procedure and the trimester of admission did not affect the risk of preterm delivery.

CONCLUSION

Although the incidence of nephrolithiasis requiring hospital admission during pregnancy is relatively low, these women have an increased risk of preterm delivery. This has potential implications for counseling of pregnant women with kidney stones requiring hospital admission. Additionally, it may prompt definitive treatment of small, asymptomatic stones in women during reproductive years.

Urolithiasis in pregnancy

The presentation of urolithiasis is often dramatic, but rarely is it more anxiety provoking than during pregnancy. The evaluation and the intervention are often approached with trepidation as the health of the mother and the fetus must be taken into account. The typical diagnostic course and surgical management used in the nonpregnant population must be reevaluated in the expectant mother. Failure to promptly diagnose and manage urolithiasis during pregnancy may have adverse consequences for mother and child. The authors present a review of the relevant anatomic and physiologic changes of pregnancy as they affect stone disease and outline options for radiologic evaluation and surgical management.

Urolithiasis in Pregnancy: Current Diagnosis, Treatment, and Pregnancy Complications

Urolithiasis complicates up to one in every 200 pregnancies; consequently, the practicing obstetrician should be aware of the symptoms of urolithiasis, the diagnostic procedures available for its diagnosis, and their associated risks. These include ultrasound, urography, and magnetic resonance imaging. Diagnosis of urolithiasis during pregnancy can be a challenge as a result of the normal physiological changes of pregnancy. Conservative management is the first-line treatment for noncomplicated urolithiasis in pregnancy. If spontaneous passage of the stone does not occur or if complications develop, urologic consultation should be obtained. Several obstetric complications have been associated with urolithiasis, including preterm labor and preterm premature rupture of membranes, although the reported rates of these complications in association with urolithiasis vary widely and overlap normal background rates. Given that urolithiasis will be encountered by most obstetricians, and that obstetricians are often on the front line of management for this condition, an appreciation of current diagnostic modalities, treatment protocols, and associated potential obstetric complications is warranted.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to recall that urolithiasis is common in pregnancy, state that there are a variety of diagnostic procedures, summarize that conservative treatment is usually successful, and explain that complications of pregnancy usually occur when there is failure of conservative treatment.

Success and Short-term Complication Rates of Percutaneous Nephrostomy during Pregnancy

Outcome of percutaneous nephrostomy creation during pregnancy was retrospectively studied. Catheter insertion was successful in all cases (N = 8; 3% of all nephrostomies over a 5-year period), with one major complication (sepsis) and three minor complications. Catheters remained in situ for a mean of 9.4 days until the stone passed (n = 1) or was removed on ureteroscopy (n = 2) or a ureteral stent was inserted (n = 5). Maternal outcome was normal in all cases, but there were two premature deliveries. Nephrostomy during pregnancy has acceptable technical and clinical results, but the possibility of an increased risk of septic complications (12.5% in this series) necessitates further study.

Outcomes and complications of pregnancy in women with primary hyperoxaluria

BACKGROUND

Information about pregnancy in females with primary hyperoxaluria types I and II (PH-I, PH-II) is limited to isolated case reports. This study sought to determine the number and outcomes of pregnancies in a series of women with PH-I and PH-II, to assess the incidence of complications during pregnancy, and to characterize infant outcomes.

METHODS

From a database of patients with PH followed at the Mayo Clinic, we identified 16 females who had been pregnant. A retrospective medical record review and telephone survey were performed.

RESULTS

Forty pregnancies occurring between 1961 and 1998 were identified: 26 pregnancies in 11 patients with PH-I and 14 pregnancies in 5 patients with PH-II. Thirty (75%) of the pregnancies were carried to term, and 33 infants were born. Four miscarriages, 4 preterm births, and 2 elective abortions occurred. No maternal complications were reported in half of the pregnancies. In the remaining pregnancies, the most common complications were hypertension, urinary tract infection, and urolithiasis-associated symptoms. One PH-I patient developed pre-eclampsia resulting in a stillborn infant, and another PH-1 patient developed hyperemesis gravidarum with a decline in renal function. Approximately 75% of the infants had no perinatal problems. All of the PH-I patients eventually required initiation of renal replacement therapy at a mean of 17.5 years following their first pregnancy. No PH-II patients have required renal replacement therapy.

CONCLUSION

Overall, pregnancy appeared to be well tolerated in this series of women with primary hyperoxaluria, with 1 of 16 women experiencing loss of renal function during 1 of 40 pregnancies.

Nephrolithiasis and pregnancy

PURPOSE OF REVIEW

Urolithiasis during pregnancy is not common, however, it is a difficult condition to both diagnose and treat. There are many safety concerns that must be considered for both the mother and fetus. In this review we detail the different options available to the urologist and we highlight a treatment algorithm that we use when faced with a pregnant patient suspect of having a urinary calculus.

RECENT FINDINGS

Changes in ultrasound, limited intravenous urograms and magnetic resonance imaging have improved our ability to diagnose urolithiasis in pregnancy. Additionally ureteroscopy has emerged not only as a diagnostic tool but also as a modality for definitive treatment that can safely be used during the intrapartum period.

SUMMARY

When diagnosing urolithiasis in the gravid patient, the first line study should be ultrasound, using change in resistive index and transvaginal ultrasound. If these are not diagnostic, then a limited intravenous urograms should be performed. Once a diagnosis has been established, initial treatment should be conservative since 70-80% of patients will pass their stones. When intervention is necessary, the placements of an internal stent or percutaneous nephrostomy tube or ureteroscopy with definitive stone treatment are all reasonable options.