Kidney stones during pregnancy: an investigation into stone composition

The role of pharmacological interventions in managing urological complications during pregnancy and childbirth: A review

Pregnancy leads to a number of structural and functional changes in the urinary system, which makes females susceptible to urological complications. This review aims to discuss the epidemiology, complications and prevention and management of urinary tract infections (UTIs), kidney stones and bladder dysfunction in pregnancy. UTIs are the most common urological problem presenting in 10% of pregnant women; Escherichia coli is the most common causative organism. If left untreated, UTIs lead to acute pyelonephritis which occurs in about 2% of pregnant women and which has serious consequences for both the mother and the baby. Kidney stones, although rare, are hazardous, occurring in 1 in 200 to 1 in 1500 pregnancies, and may cause obstructive uropathy, and aggravation of "labor-like" pain. Urological complications are frequent in pregnancy; bladder dysfunction alone has been documented to affect 50% of the pregnant women. Urological complications can have severe consequences when not properly managed including preterm labor and renal dysfunction. In order to have the best pharmacological care, safe use of antibiotics for UTIs is needed along with other measures for kidney stones. This review highlights the importance of a team approach to patient management to optimize outcome and touches briefly on some of the ethical dilemmas that may be encountered when drug therapy in pregnancy is being considered. Therefore, it is feasible to enhance the health of women and the fetus during this period through patient focused care and innovative interventions.

Management of urolithiasis in pregnancy

Urolithiasis is the most common cause of nonobstetric abdominal pain, resulting in 1.7 admissions per 1000 deliveries. Urolithiasis most commonly occurs in the second and third trimesters, with an incidence between 1:125 and 1:2000. Acute urinary system obstructions are challenging to manage in obstetric patients because they contribute to physiological and anatomical changes that result in pathological outcomes. The restricted use of computed tomography in diagnosing and managing urolithiasis is particularly challenging. In addition, a prompt diagnosis is required because the presence of renal calculi during pregnancy increases the risk of fulminating sepsis and preterm delivery. Affected pregnancies are conservatively managed; however, 1 in 4 requires surgical intervention. Indications for surgical interventions are complex and range from nephrostomy insertion to empirical stent placement or ureteroscopy. Therefore, a multidisciplinary approach is required to optimize patient care. The diagnosis and management of urolithiasis in pregnancy are complex. We reviewed the role, safety, advantages and disadvantages of diagnostic tests and treatment used to manage acute urinary obstructions in pregnancy.

A Systematic Review of Elective Laser Therapy during Pregnancy

Introduction: Currently, lasers are used to treat many diseases and their complications. However, the use of lasers in pregnant patients is still controversial. Methods: In this review, the application of lasers in the fields of urology, surgery, obstetrics, dermatology, and musculoskeletal disorders is evaluated. The following keywords were used to search through PubMed, Google Scholar, and Scopus: pregnancy, laser, urolithiasis, endovenous laser ablation (EVLA) or treatment, leg edema, varicose vein, venous insufficiencies, hair removal, pigmentation, telangiectasia, vascular lesions, Q switch laser, diode laser, holmium, holmium-YAG laser, erbium laser and Pulsed dye laser, low-level laser therapy, high-intensity laser therapy, pain, musculoskeletal disorders, twin to twin transfusion syndrome (TTTS), amnioreduction, and safety. Results: Totally, 147 articles were found, and their abstracts were evaluated; out of 53 articles extracted, 14 articles were about dermatology, 24 articles were about urology, 12 articles were about obstetrics and gynecology, 10 articles were about musculoskeletal disorders and three articles were related to surgery. Conclusion: Laser therapy can be used as a safe treatment for urolithiasis, skin diseases, TTTS and varicose veins of the lower extremities. However, the use of laser therapy for musculoskeletal disorders during pregnancy is not recommended due to lack of evidence, and also we cannot recommend endovenous ablation.

Urinary Tract Infections Spectrum During Pregnancy: Etiopathogenesis and Outcome

Background :The occurence of urinary tract infections (UTIs) in the course of a normal pregnancy should always be early diagnosed and treated, even asymptomatic as it could evolve to threatening pathological conditions, like sepsis with acute kidney injury, or preeclampsia. The aim of study was to establish a cartographic projection of the risk factors and etiopathogenesis of urinary tract infections diagnosed during pregnancy, with the purpose to control their severity and evaluate the therapeutic strategies used to reduce maternal and fetal risks.

Material and methods: The study included 175 patients, pregnant women, diagnosed with UTIs hospitalized in the Nephrology Clinic and Obstetrics-Gynecology Clinic of the Emergency Clinical County Hospital of Constanta, in an interval of time of 4 years, between 2017-2021.

Results: Out of the 247 patients recruited in our study, the distribution according to the trimester of pregnancy, there were : 72 pregnant women in the first trimester (41.14%), 35 in the second trimester (20.0%) and 68 in the third trimester (38.86%). The frequency of pregnant women who had other favorising conditions and detectable risk factors was 70.29%. The clinical manifestations of UTIs in our study group were distributed as follows : 36 (20.57%) asymptomatic bacteriuria, 56 (32.0%) acute cystitis, 44 (25.14%) recurrent lower urinary tract infections, and 39 (22.29%) acute pyelonephritis. There is an association (p ---lt--- 0.001) between the type of clinical form of UTIs and a certain trimester of pregnancy, for example the highest frequency of acute pyelonephritis (AP) was noticed in the third trimester of pregnancy (71.8%, 28/39). Out of 39 pregnant women with AP, 71.8% (28) had associated ureterohydronephrosis (UHN). E. Coli was present in 41.71% of pregnant women., followed by Klebsiella pneumoniae, Enterococcus faecalis and, less frequently, Staphylococcus aureus and Proteus mirabilis. The most frequently used antibiotics in pregnancy were: 2nd and 3rd generations of cephalosporins (42.29%), followed by ampicillin (34.29%); less used were amoxicillin with clavulanic acid (10.29%), quinolones (6.29%) and nitrofurantoin (6.86%). Most of the pregnant women (94.28%, 165/175) had remission of fever within 24-48 h of using appropriate antibiotic therapy. The recurrence rate was 22.28 %, (39/175).

Conclusion All clinical forms of UTIs could be present during pregnancy, but the most common are lower urinary tract infections and the most involved germ is E. Coli. UHN is a factor that influences the occurence of UTIs, being the most common favorising condition.

Risk of Symptomatic Kidney Stones During and After Pregnancy

RATIONALE & OBJECTIVE

There are several well-known anatomical and physiological changes during pregnancy that could contribute to kidney stone formation, but evidence that they increase the risk of kidney stones during pregnancy is lacking. We determined whether there was an increased risk of a first-time symptomatic kidney stone during and after pregnancy.

STUDY DESIGN

A population-based matched case-control study.

SETTING & PARTICIPANTS

945 female first-time symptomatic kidney stone formers aged 15-45 years and 1,890 age-matched female controls in Olmsted County, MN, from 1984-2012. The index date was the date of onset of a symptomatic kidney stone for both the case and her matched controls.

EXPOSURE

The primary exposure was pregnancy with assessment for variation in risk across different time intervals before, during, and after pregnancy. Medical records were manually reviewed to determine the conception and delivery dates for pregnancies.

OUTCOME

Medical record-validated first-time symptomatic kidney stone.

ANALYTICAL APPROACH

Conditional and unconditional multivariable logistic regression analysis.

RESULTS

Compared with nonpregnant women, the odds of a symptomatic kidney stone forming in women was similar in the first trimester (OR, 0.92; P=0.8), began to increase during the second trimester (OR, 2.00; P=0.007), further increased during the third trimester (OR, 2.69; P=0.001), peaked at 0 to 3 months after delivery (OR, 3.53; P<0.001), and returned to baseline by 1year after delivery. These associations persisted after adjustment for age and race or for diabetes mellitus, hypertension, and obesity. These results did not significantly differ by age, race, time period, or number of prior pregnancies. Having a prior pregnancy (delivery date>1year ago) was also associated with a first-time symptomatic kidney stone (OR, 1.27; P=0.01).

LIMITATIONS

Observational study design in a predominantly White population. The exact timing of stone formation cannot be determined.

CONCLUSIONS

Pregnancy increases the risk of a first-time symptomatic kidney stone. This risk peaks close to delivery and then improves by 1 year after delivery, though a modest risk of a kidney stone still exists beyond 1 year after delivery.

Clinical presentation and management of urolithiasis in the obstetric patient: a matched cohort study

PURPOSE

To evaluate the effect of pregnancy on the clinical presentation, inpatient procedure rates, and length of hospital stay, on women with urolithiasis.

MATERIALS AND METHODS

We carried out a matched cohort study using the United States' Healthcare Cost and Utilization Project-Nationwide Inpatient Sample database from 1999 to 2015. Pregnant women with urolithiasis were compared to age-matched non-pregnant women (1:1) with urolithiasis. Baseline clinical characteristics were compared between the two cohorts and the effect of pregnancy on select inpatient procedural and clinical outcomes was evaluated using conditional logistic regression models.

RESULTS

There were 42,113 pregnant patients diagnosed with urolithiasis during the study period. It was observed that pregnant patients were less likely to present with classic clinical symptoms of urinary tract stones, such as flank pain, OR 0.63, 95% CI 0.56-0.70, and fever, 0.22 (0.16-0.30), but tended to have longer hospital stays. The pregnant patients were less commonly affected by infectious conditions, namely urinary tract infections, 0.56 (0.53-0.59), sepsis, 0.17 (0.14-0.20), and pyelonephritis, 0.34 (0.36-0.44). Invasive and surgical procedures were less commonly performed in pregnant women.

CONCLUSIONS

Pregnant women admitted with urolithiasis appear to be less symptomatic with fewer interventions and complications than non-pregnant women with urolithiasis.

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.

Urological issues in pregnancy: A review for urologists

Urological issues in the pregnant patient present a unique clinical dilemma. These patients may be challenging to treat due to risks associated with medications and surgical procedures. This review aims to provide an update on the physiological changes and surgical risks in pregnancy. In addition, we review the approach for management of urolithiasis and urinary tract infections in pregnancy. Lastly, we highlight the importance of a multidisciplinary approach to placenta percreta, a condition not commonly addressed in urological education.

Nephrolithiasis in Pregnancy: Treating for Two

OBJECTIVES

To review the literature regarding the epidemiology of stone disease and develop a management algorithm based on current evidence and societal guidelines.

METHODS

A structured literature review was performed to determine highest quality of evidence guiding care for pregnant patients with symptomatic nephrolithiasis. PUBMED and EMBASE databases were searched using terms "pregnancy," "nephrolithiasis," or "pregnancy" and "renal colic" alone and in combination with "stone", "kidney stone," "ultrasound," "MRI," "CT," "percutaneous nephrostomy," "ureteral stent," or "ureteroscopy." All English-language abstracts were reviewed for relevance and full-length articles were reviewed for content. Articles published prior to 1990 were excluded, and priority for inclusion was given to multi-institutional studies and larger institutional studies, reflecting the highest level of current available evidence and most contemporaneous practice patterns.

RESULTS

Symptomatic nephrolithiasis affects less than 1% of pregnancies but poses unique diagnostic challenges due to the physiologic changes of pregnancy and risks of ionizing radiation exposure to the fetus. Ultrasound remains the imaging modality of choice. Most patients may be managed non-operatively, but drainage with percutaneous nephrostomy or ureteral stent may be performed if warranted. Growing evidence also supports the safety and efficacy of definitive stone treatment.

CONCLUSIONS

Though rare, symptomatic nephrolithiasis poses significant clinical challenges due to the need to minimize risk for both mother and fetus with diagnostic and therapeutic interventions. A multi-disciplinary approach is paramount, as is shared decision making with the patient at each step of care.

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.

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.

Urolithiasis in pregnancy

Urolithiasis in pregnancy is a major health concern and can potentially affect the well-being of both mother and foetus. Management of this condition often entails simultaneous multidisciplinary involvement of obstetrician, radiologist and urologist. Additionally, adverse effects with usage of anaesthesia, radiation, medications and surgery on mother and foetus, limit utilisation of the full armamentarium of diagnostic and therapeutic modalities that are commonly used in non-pregnant women. This review was conducted using an electronic literature search of peer reviewed journal articles. Clinical studies were identified in the bibliographic database- PubMed (Medline), Ovid and eMedicine(WebMD) using the keywords: hydronephrosis, urolithiasis, kidney stone, urinary tract infection, pregnancy and ultrasound, incidence and epidemiology of renal stones.

A best practice position statement on pregnancy in chronic kidney disease: the Italian Study Group on Kidney and Pregnancy

Pregnancy is increasingly undertaken in patients with chronic kidney disease (CKD) and, conversely, CKD is increasingly diagnosed in pregnancy: up to 3 % of pregnancies are estimated to be complicated by CKD. The heterogeneity of CKD (accounting for stage, hypertension and proteinuria) and the rarity of several kidney diseases make risk assessment difficult and therapeutic strategies are often based upon scattered experiences and small series. In this setting, the aim of this position statement of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology is to review the literature, and discuss the experience in the clinical management of CKD in pregnancy. CKD is associated with an increased risk for adverse pregnancy-related outcomes since its early stage, also in the absence of hypertension and proteinuria, thus supporting the need for a multidisciplinary follow-up in all CKD patients. CKD stage, hypertension and proteinuria are interrelated, but they are also independent risk factors for adverse pregnancy-related outcomes. Among the different kidney diseases, patients with glomerulonephritis and immunologic diseases are at higher risk of developing or increasing proteinuria and hypertension, a picture often difficult to differentiate from preeclampsia. The risk is higher in active immunologic diseases, and in those cases that are detected or flare up during pregnancy. Referral to tertiary care centres for multidisciplinary follow-up and tailored approaches are warranted. The risk of maternal death is, almost exclusively, reported in systemic lupus erythematosus and vasculitis, which share with diabetic nephropathy an increased risk for perinatal death of the babies. Conversely, patients with kidney malformation, autosomal-dominant polycystic kidney disease, stone disease, and previous upper urinary tract infections are at higher risk for urinary tract infections, in turn associated with prematurity. No risk for malformations other than those related to familiar urinary tract malformations is reported in CKD patients, with the possible exception of diabetic nephropathy. Risks of worsening of the renal function are differently reported, but are higher in advanced CKD. Strict follow-up is needed, also to identify the best balance between maternal and foetal risks. The need for further multicentre studies is underlined.

Association Between Recurrence of Urinary Calculi and Childbirth: A Population-Based Case-Control Study

We examined the recurrence rate of urinary calculi (UC) in women after childbirth. The recurrence of UC is common, but no previous studies mentioned the risk of recurrence after childbirth. We performed a nationwide population-based cohort study to investigate whether childbirth could correlate with the recurrence of UC by using data from the National Health Insurance Research Database in Taiwan. Nulliparous women (age ≥20 years) receiving a diagnosis of first episode of UC between 2000 and 2002 were enrolled. We recorded the events of recurrence between parous patients (n = 737) and matched-control nulliparous patients (n = 737). The average ages for parous patients and controls were 27.41 and 27.54, respectively. The recurrence rate was 11.67% (86 of 737) in the childbirth cohort group and 21.57% (159 of 737) in the nonchildbirth cohort group. The childbirth cohort group was associated with a significantly decreased risk of secondary UC (adjusted hazard ratio, 0.45; 95% confidence interval, 0.35–0.59) compared with those who did not deliver a child. This relationship should be studied further.

Biomedical investigations using Fourier transform-infrared microspectroscopy

One of the most exciting recent developments in infrared spectroscopy has been the coupling of the spectrometer to an infrared microscope. The combination of the new infrared spectrometer and a microscope was a natural thought of scientists in these fields. This development has been so rewarding and so useful in solving today's chemical problems that infrared microspectroscopy has quickly become a significant subclassification of infrared spectroscopy. Infrared microspectroscopy has a much longer history than the recent enthusiasm would imply, however. The great interest in the use of infrared spectroscopy to solve biomedical problems that occurred in recent years shortly spread into the medical and biological fields. The aim of this review is to discuss the new developments in applications of FT-IR microspectroscopy in biomedical analysis, covering the period between 2008 and 2013.

Definitive ureteroscopy and intracorporeal lithotripsy in treatment of ureteral calculi during pregnancy

Objective

To evaluate the outcome of using semi-rigid ureteroscopy with or without intracorporeal pneumatic lithotripsy vs. temporary ureteric JJ stenting in the management of obstructing ureteric calculi in pregnant women.

Patients and methods

This prospective comparative study comprised 43 pregnant women with obstructing ureteric calculi. The diagnosis was based on the acute flank pain as the main symptom, microscopic haematuria, and unilateral hydronephrosis on abdominal ultrasonography (US). The patients were randomly divided into two groups; those in group 1 (22 patients) were treated by temporary ureteric JJ stenting until after delivery, and those in group 2 (21) were treated definitively by ureteroscopic stone extraction with intracorporeal pneumatic lithotripsy. Postoperative complications and the degree of patient satisfaction were reported.

Results

An obstructing ureteric stone was identified by US in 68% and 76% of groups 1 and 2, respectively. In group 1, nine patients had mid-ureteric stones and 13 had stones in the lower ureter. In group 2, seven patients had mid-ureteric stones, whilst the stones were in the distal ureter in 14. No perioperative foetal complications were detected in any group and all patients completed the full term of pregnancy. In group 1, four patients had a postoperative urinary tract infection (UTI), and the JJ stent was exchanged in seven. Two patients in group 2 had a postoperative UTI.

Conclusions

Definitive ureteroscopy, even with intracorporeal pneumatic lithotripsy, is an effective and safe treatment for pregnant women with obstructing ureteric calculi. It has a better outcome and is more satisfactory for the patients than a temporary JJ stent.

Renal stones in pregnancy

Diagnosis and treatment of renal stones during pregnancy is a complex problem. Risks to the fetus from ionising radiation and interventional procedures need to be balanced with optimising clinical care for the mother. Management of such patients requires a clear understanding of available options, with a multidisciplinary team approach. In this review, we discuss the role of different diagnostic tests including ultrasound, magnetic resonance urography, and computerized tomography. We also provide an update on recent developments in the treatment of renal stones during pregnancy. Expectant management remains first-line treatment. Where definitive treatment of the stone is required, new evidence suggests that ureteroscopic stone removal may be equally safe, and possibly better than traditional temporising procedures.

Imaging for acute pelvic pain in pregnancy

Acute pelvic pain in pregnancy presents diagnostic and therapeutic challenges. Standard imaging techniques need to be adapted to reduce harm to the foetus from X-rays because of their teratogenic and carcinogenic potential. Ultrasound remains the primary imaging investigation of the pregnant abdomen. Magnetic resonance imaging (MRI) has been shown to be useful in the diagnosis of gynaecological and obstetric problems during pregnancy and in the setting of acute abdomen during pregnancy. MRI overcomes some of the limitations of ultrasound, mainly the size of the gravid uterus. MRI poses theoretical risks to the foetus and care must be taken to minimise these with the avoidance of contrast agents. Teaching Points • Ultrasound and MRI are the preferred investigations for acute pelvic pain during pregnancy. • Ultrasound remains the primary imaging investigation because of availability and portability. • MRI helps differentiate causes of acute pelvic pain when ultrasound is inconclusive.

Etiology, Diagnosis and Treatment of Renal Colic during Pregnancy

Objectives

To assess the incidence and causes of renal stones in pregnant women, investigate the reliability and accuracy of diagnostic investigations and to consider the various therapeutic options available.

Methods

A review of the literature was conducted, searching for relevant papers on the physiology of urinary apparatus changes during pregnancy, as well as the etiology, diagnosis and management of renal colic in pregnant women.

Results

Standards of care in renal colic during pregnancy include accurate diagnosis primarily with ultrasound, or MRI if necessary, conservative therapy and careful surgical approach for urinary drainage in the first place or ureterorenoscopy when needed.

Conclusions

Renal colic during pregnancy is potentially troublesome and likely to lead to serious adverse effects on both mother and fetus. A multi-disciplinary approach is needed, which includes experts in the fields of Urology, Obstetrics, Radiology and Anesthesiology, to ensure the optimal care of this delicate cohort of patients.

Kidney stones and pregnancy

Kidney stones are common and do not spare the pregnant population. Although a simple stone event is usually straightforward in the general population, it is complex during pregnancy. Acute nephrolithiasis is associated with a unique set of complications during pregnancy and, because of imaging limitations, diagnosis is challenging. Multidisciplinary care is the key in proper management decisions. The pathophysiology of kidney stone formation in the pregnant state is also unique. Herein, we discuss the complexity of kidney stones and pregnancy.

Renal disease in pregnancy ambulatory issues

Acute and chronic renal disease will complicate prenatal care. Normal physiological changes during pregnancy make the urinary tract system more vulnerable to infectious complications or worsening of preexisting disease. Much of the focus of prenatal care includes screening for these concerns both at the onset of prenatal care and through the pregnancy and postpartum course. With careful and attentive care, the pregnancy outcome for women with significant renal disease has improved and the occurrence of renal injury or obstetric complications due to infectious insults has decreased. This manuscript reviews the current ambulatory prenatal care as it relates to the urinary tract in pregnancy.

Calcium orthophosphates: occurrence, properties, biomineralization, pathological calcification and biomimetic applications

The present overview is intended to point the readers' attention to the important subject of calcium orthophosphates. This type of materials is of special significance for human beings, because they represent the inorganic part of major normal (bones, teeth and antlers) and pathological (i.e., those appearing due to various diseases) calcified tissues of mammals. For example, atherosclerosis results in blood vessel blockage caused by a solid composite of cholesterol with calcium orthophosphates, while dental caries and osteoporosis mean a partial decalcification of teeth and bones, respectively, that results in replacement of a less soluble and harder biological apatite by more soluble and softer calcium hydrogenphosphates. Therefore, the processes of both normal and pathological calcifications are just an in vivo crystallization of calcium orthophosphates. Similarly, dental caries and osteoporosis might be considered an in vivo dissolution of calcium orthophosphates. Thus, calcium orthophosphates hold a great significance for humankind, and in this paper, an overview on the current knowledge on this subject is provided.

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.

Calcium Orthophosphates in Nature, Biology and Medicine

The present overview is intended to point the readers’ attention to the important subject of calcium orthophosphates. These materials are of the special significance because they represent the inorganic part of major normal (bones, teeth and dear antlers) and pathological (i.e. those appearing due to various diseases) calcified tissues of mammals. Due to a great chemical similarity with the biological calcified tissues, many calcium orthophosphates possess remarkable biocompatibility and bioactivity. Materials scientists use this property extensively to construct artificial bone grafts that are either entirely made of or only surface-coated with the biologically relevant calcium ortho-phosphates. For example, self-setting hydraulic cements made of calcium orthophosphates are helpful in bone repair, while titanium substitutes covered by a surface layer of calcium orthophosphates are used for hip joint endoprostheses and as tooth substitutes. Porous scaffolds made of calcium orthophosphates are very promising tools for tissue engineering applications. In addition, technical grade calcium orthophosphates are very popular mineral fertilizers. Thus ere calcium orthophosphates are of great significance for humankind and, in this paper, an overview on the current knowledge on this subject is provided.