Hydronephrosis during pregnancy: four cases of hydronephrosis causing symptoms during pregnancy

Excessive urinary tract dilatation and proteinuria in pregnancy: a common and overlooked association?

BACKGROUND

Proteinuria and dilatation of the urinary tract are both relatively common in pregnancy, the latter with a spectrum of symptoms, from none to severe pain and infection. Proteinuria is a rare occurrence in acute obstructive nephropathy; it has been reported in pregnancy, where it may pose a challenging differential diagnosis with pre-eclampsia.The aim of the present study is to report on the incidence of proteinuria (≥ 0.3; ≥ 0.5 g/day) in association with symptomatic-severe urinary tract dilatation in pregnancy.

METHODS

Case series.

SETTING

Nephrological-Obstetric Unit dedicated to pregnancy and kidney diseases (January 2000-April 2011).

SOURCE

database prospectively updated since the start of the Unit. Retrospective review of clinical charts identified as relevant on the database, by a nephrologist and an obstetrician.

RESULTS

From January 2000 to April 2011, 262 pregnancies were referred. Urinary tract dilatation with or without infection was the main cause of referral in 26 cases (predominantly monolateral in 19 cases): 23 singletons, 1 lost to follow-up, 1 twin and 1 triplet. Patients were referred for urinary tract infection (15 cases) and/or renal pain (10 cases); 6 patients were treated by urologic interventions ("JJ" stenting). Among them, 11 singletons and 1 triple pregnancy developed proteinuria ≥ 0.3 g/day (46.1%). Proteinuria was ≥ 0.5 g/day in 6 singletons (23.1%). Proteinuria resolved after delivery in all cases. No patient developed hypertension; in none was an alternative cause of proteinuria evident. No significant demographic difference was observed in patients with renal dilatation who developed proteinuria versus those who did not. An association with the presence of "JJ" stenting was present (5/6 cases with proteinuria ≥ 0.5 g/day), which may reflect both severer obstruction and a role for vescico-ureteral reflux, induced by the stent.

CONCLUSIONS

Symptomatic urinary tract dilatation may be associated with proteinuria in pregnancy. This association should be kept in mind in the differential diagnosis with other causes of proteinuria in pregnancy, including pre-eclampsia.

Colour Doppler evaluation of ureteral jets in normal second and third trimester pregnancy: effect of patient position

The study was designed to investigate the effect of patient position on the detection of ureteral jets in normal pregnancy. The number of jets was recorded for 1 min using colour Doppler ultrasound in 26 healthy asymptomatic gravid women between 16 weeks and 34 weeks gestation. Each patient was examined in the supine position and in both the right and left lateral decubitus positions. Ureteral jets were present on at least one side in 24 patients in the supine position compared with 26 women in the lateral decubitus position. 13 (54%) of the 24 patients in whom jets were seen in the supine position had jets on only one side. A mean of 1.80 jets x min(-1) was detected on the right side and 3.23 jets x min(-1) on the left (p=0.046) in the supine position. In the contralateral decubitus position, jets were detected on the right side in 22 (85%) women and on the left in 25 (96%) women. A mean of 3.07 jets x min(-1) was detected on the right and 4.15 jets x min(-1) on the left. The difference in the frequency of ureteral jets between the supine and lateral decubitus positions was significant (p=0.004 for the right; p=0.011 for the left). However, the difference in the detection rate was significant on only the right side (p=0.016 for the right; p=0.063 for the left). 10 (77%) of 13 patients in whom unilateral absence of ureteral jets was noted had detectable jets in the lateral decubitus position. Our findings demonstrated the utility of the lateral decubitus position in the evaluation of ureters suspicious for obstruction. However, caution is still recommended in diagnosing ureteral obstruction if jets are persistently absent after this manoeuvre.

Ultrasonographic detection of ureteral jets in normal pregnancy

OBJECTIVE

Our purpose was to determine the impact of normal physiologic urodynamic alterations of pregnancy on the detection of ureteral jets into the bladder with use of transabdominal color Doppler ultrasonography.

STUDY DESIGN

We conducted a prospective cohort study of 125 healthy asymptomatic gravid women without any history of past or current renal disease, all with singleton pregnancies between 13.4 and 37.7 weeks' gestation. Right and left ureteral jets were recorded over a 5-minute period with use of color Doppler transabdominal ultrasonography and a full bladder. Each kidney was graded by the severity of the hydronephrosis. No hydronephrosis was grade 0, mild hydronephrosis was grade 1, and moderate hydronephrosis was grade 2. There were no cases of severe hydronephrosis.

RESULTS

There were 56 grade 0 cases on the right versus 93 grade 0 cases on the left (p < 0.0001), 53 versus 30 grade 1 cases (right vs left, p < 0.003) and 16 versus 2 grade 2 cases (right vs left, p < 0.0009). In the subgroup where both kidneys were grade 0 the mean number of right ureteral jets 5 mm was 14.7 versus 15.1 for the left ureteral jets (p = 0.73). In the grade 1 subgroup mean right versus left ureteral jets was 15.4 versus 16.6 (p = 0.65). For the grade 2 subgroup mean right versus left ureteral jets was 15.5 versus 21.0 (p = 0.32). There were 4 of 125 unilateral absent ureteral jets on the right versus 0 of 125 on the left (p = 0.122).

CONCLUSION

Our data demonstrate that ureteral jets can be readily detected during pregnancy independent of the gestational age. In addition, it does not appear that the physiologic urodynamic alterations of pregnancy affect the frequency or symmetry of ureteral jets. Thus identification of ureteral jets can be used in the workup of suspected urolithiasis in pregnant patients.

Dilatation of the urinary tract during pregnancy: proposal of a curve of maximal caliceal diameter by gestational age

OBJECTIVE

Dilatation of the urinary tract is common during pregnancy, but the limits between physiologic and pathologic dilatation are unknown. Our purpose was to establish the pattern of physiologic urinary tract dilatation during pregnancy.

STUDY DESIGN

This was a cross-sectional study. The maximal caliceal diameter was measured by ultrasonography at different weeks' gestational age in 1506 pregnant and 181 postpartum women. A curve with the 90th, 75th, and 50th percentiles was drawn for each kidney.

RESULTS

Fifty-three (6%) pregnant and postpartum women had some degree of dilatation. The right kidney was more frequently and severely affected, as were nulliparous women. The 90th percentile of maximal caliceal diameter of the right kidney increased about 0.5 mm/wk up to 24 to 26 weeks, about 0.3 mm/wk up to 31 to 32 weeks, and remained stable until term. The left maximal caliceal diameter attained 8 mm around week 20 to 24 and remained stable until term. Only 6% had dilatation in the postpartum period.

CONCLUSION

A normal curve of dilatation of the urinary tract is proposed.

Infected Hydronephrosis of Pregnancy with Renal Abscess Formation: Role of the Percutaneous Nephrostomy

Hydronephrosis of pregnancy is a physiological phenomenon and usually asymptomatic. When it becomes associated with intractable or prolonged pain, infection refractory to antibiotics or extreme dilatation damaging the obstructed kidney, invasive intervention is necessary. Percutaneous nephrostomy is the procedure of choice for draining the acutely obstructed kidney early, rapidly and continuously. We present two cases of unusual severity, one of them being the first report of renal abscess formation complicating hydronephrosis of pregnancy. The role, advantages and some technical points of percutaneous nephrostomy are discussed.

Sonographic visualization of the ureter in pregnancy

We describe a method of differentiating physiological from pathological dilatation of the renal collecting system in pregnant patients. In physiological hydronephrosis the dilated ureter extends down only to the level of the common iliac artery. In 2 patients with distal ureteral stones a dilated ureter was visualized past the vessels. To determine the frequency and reliability of visualizing the ureters in pregnant patients 105 consecutive asymptomatic pregnant patients were examined. Hydronephrosis was found in 83 kidneys in 59 of the patients. The dilated ureter was visualized in 64 of the renal units. The anatomy was well demonstrated by color flow Doppler scanning and in all of these cases the dilated ureter was seen to taper where it crossed the common iliac artery. These results suggest that the presence of a dilated ureter past the iliac artery is strong evidence for pathological distal ureteral obstruction in pregnancy.

Hydronephrosis during pregnancy: a literature survey

The occurrence of hydronephrosis and hydroureters during pregnancy has been termed physiological, inasmuch as it is seen in more than 80%, most frequently and most pronounced in primigravida. The dilatation develops during the second trimester, and becomes more prominent on the right side, is only seen above the linea terminalis and disappears within a few weeks after birth. The condition is not seen in women whose ureters do not cross the pelvic brim. The extent of the dilatation can be reduced by placing the woman on the side least affected or in the knee-elbow position. After a survey of the literature, the conclusion is reached that today there is every probability that hydronephrosis during pregnancy develops as a result of compression of the ureters between the pregnant uterus and the linea terminalis. It has not been demonstrated that the change in hormonal balance during pregnancy is of importance. The clinical significance of hydronephrosis lies in the association between ureteral obstruction and the high frequency of ascending urinary tract infection during pregnancy and in the understanding of the importance--in the treatment of infection--of improving drainage by means of a change in position. Isotope renographic studies seem to show a possible relationship between bilateral ureteral obstruction and the development of pre-eclampsia. Similarly, it appears that acute hydronephrosis or worsening of an existing hydronephrosis has been somewhat overlooked as a possible cause of uncertain abdominal pain during pregnancy. These conditions should be examined by means of ultrasonography, and an attempt at treatment by a change in position should be made. In cases of continued pain or affected renal function, treatment should consist of the insertion of a ureteral catheter.