Discussion
This study with prospectively evaluated pregnant women demonstrated that
the degree of hydronephrosis and the number of pregnancies correlated
with the severity of pain. While our findings are similar with the
literature at some points, they seem to support the opposite view with
some others. The incidence of acute flank pain and hydronephrosis more
on the right side is consistent with the literature.(4, 5, 10) Some studies reported that hydronephrosis
is more common especially in primigravidae (1, 5). In
our study, especially in the nulliparous, hydronephrosis and pain were
found to have medium level, positive correlation. In the literature
there are studies which state that hydronephrosis is common in pregnant
women; that there is no relationship between hydronephrosis and acute
flank pain and that most cases develop asymptomatically(5, 8). Farr et al. reported that hydronephrosis was
not observed in some of the patients with flank pain.(11). In the same study, Farr et al. stated there was
no correlation between hydronephrosis and pain intensity(11). Many studies in the literature investigated
hydronephrosis and its prevalence and the relationship between
hydronephrosis and pain. The main difference in our study was that all
patients were admitted with acute flank pain. Detection of
hydronephrosis in all the pregnant women included in our study made us
consider hydronephrosis to be associated with acute flank pain. It is
also possible that anatomic factors and gestational anxiety might have
been effective in the positive correlation between the pain and the
degree of hydronephrosis and in higher VAS scores of the nulliparous
than the multiparous (12). In lack of concrete
evidence such as psychiatric examination results, we think that this may
be subject of another study.
In the literature, cases of complicated urinary tract infection such as
pyelonephritis that developed during and after the second trimester and
causing serious complications were reported (13). No
patients with urinary tract infection were included in our study and
none of the patients included in the study developed pyelonephritis
later. The majority of patients (91.7%) benefited from conservative
treatment. Only 4 patients (8.3%) underwent ureteral JJ stent
placement. This ratio is consistent with the literature, yet the small
number of patients is a limiting factor for a strong interpretation(5).
The most important difference that distinguish our study from other
studies is the comparison between multipar and nulliparous patients and
assessing only the relationship between flank pain and degree of
hydronephrosis. In some studies, patients with symptom like fever and
signs like WBC and CRP increase were included to study(14). In contrast to these studies, patients who had
only flank pain and normal biochemical tests but had no symptoms like
fever were included to our study. We think that our study also enables a
stronger evaluation for the relationship between hydronephrosis and
flank pain without different symptoms and signs. In some studies, it has
been reported that hydronephrosis is common during pregnancy and is
asymptomatic (5, 8). However, patients with mild
hydronephrosis were also included in these studies, and pregnant women
with mild hydronephrosis constitute the vast majority. In our study,
there are patients in the late periods of the second trimester and in
the third trimester. As a result, we think that hydronephrosis increases
with the progression of pregnancy and pain associated with it is
observed.
As we were the only urology center in the city, all patients were
followed up by the same team. Ureteral JJ stent placed in one of the
patients was removed before delivery and the other three stents were
removed about 3-4 weeks after delivery. Removal of one of the stents
before delivery was done upon the demand of the patient due to hematuria
and irritative stent symptoms. No major complication developed in the
patients with ureteral JJ stents. Although we cannot make a strong
interpretation due to the small number of patients, this result is
consistent with the literature (15). The degrees of
hydronephrosis in the patients who were placed stents were grade 2 and
grade 3 (n = 1, n = 3, respectively) and their VAS scores were 9 and 10
(n = 2, n = 2, respectively). In concurrence with the study of Tsai et
al. we think that JJ stent is more effective than conservative treatment
in pregnant women with advanced hydronephrosis (15).
JJ stents may be applied as a reliable method in these patients. The
most important limiting factor of our study was the number of patients.
A stronger result could be obtained with more patients. Birth and
postnatal data of the patients included in our study are not available
as well.