http://informahealthcare.com/jmf ISSN: 1476-7058 (print), 1476-4954 (electronic) J Matern Fetal Neonatal Med, 2015; 28(9): 1053–1056 ! 2014 Informa UK Ltd. DOI: 10.3109/14767058.2014.942631
ORIGINAL ARTICLE
Is there a relationship between the grade of maternal hydronephrosis and birth weight of the babies? Soner Coban1, Ismail Biyik2, Emin Ustunyurt3, Ibrahim Keles4, Muhammed Guzelsoy1, and Hakan Demirci5 J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 07/15/15 For personal use only.
1
Department of Urology, Sevket Yilmaz Education and Research Hospital, Bursa, Turkey, 2Department of Obstetrics and Gynecology, Karacabey State Hospital, Bursa, Turkey, 3Department of Obstetrics and Gynecology, Sevket Yilmaz Education and Research Hospital, Bursa, Turkey, 4 Department of Urology, Afyon Kocatepe University, Afyon, Turkey, and 5Department of Family Medicine, Sevket Yilmaz Education and Research Hospital, Bursa, Turkey Abstract
Keywords
Mild hydronephrosis may be present in upto 90% of pregnancies. The degree of hydronephrosis was determined by maximal calyceal diameter (MCD). The aim of this study is to investigate whether there is a relationship between grade of maternal hydronephrosis and birth weight of the babies. Subjects were examined in three groups: group 1 MCD of 5–10 mm (grade I), group 2 10–15 mm (grade II) and group 3 patients 415 mm (grade III). There were 45, 30, 13 patients in the groups, respectively. Estimated fetal weight (EFW) at the time that hydronephrosis was diagnosed, birth weight and duration of pregnancy were compared. The average birth weight of the babies was not statistically different in the three groups (p40.05), but there was a statistically significant difference in fetal weights at the time of diagnosis (p ¼ 0.02). The grade of maternal hydronephrosis does not affect the duration of pregnancy.
Fetal birth weight, fetal weight, maternal hydronephrosis
Introduction Pregnancy induced asymptomatic hydronephrosis is seen in 90% of pregnancies [1,2]. However, acute symptomatic dilatation of calixes, renal pelvis and ureters is seen in 0.2–3% of pregnancies [3,4]. Hydronephrosis is more commonly observed in primiparous pregnancies and dilatation is more prominent in the right kidney and ureter [4–6]. It frequently occurs in the second half of the pregnancy. The pathogenesis of the dilatation can be explained by two mechanisms: a mechanical pressure of the uterus on the ureters and relaxation of smooth muscles due to progesterone [4–7]. The explanation for three-fold more common dilatation in the right kidney compared to the left kidney are the dextra rotation of the enlarged uterus during pregnancy and a protective effect of the sigmoid colon for the left ureter from mechanical pressure [8,9]. The importance of mechanical pressure is supported by the fact that urinary system dilatation is more common in twin pregnancies and polyhydramniosis cases [9]. Fetal weight may increase the probability of a larger uterus. However, there are a limited number of studies on the relationship between
Address for correspondence: Ismail Biyik, MD, Department of Obstetrics and Gynecology, Karacabey State Hospital, Tavsanli Street 56, Road No: 4, Karacabey, Bursa 16700, Turkey. Tel: +905327867031. Fax: 0(224)6762450. E-mail: [email protected]
History Received 20 May 2014 Revised 18 June 2014 Accepted 4 July 2014 Published online 28 July 2014
maternal hydronephrosis and fetal weight. In the present study, we aimed to search the relationship between the grade of maternal hydroneprosis and birth weight of the babies.
Materials and methods This study was designed as a retrospective study and data of 5800 singleton pregnancies during the period January 2010 to June 2013 was analyzed. There were 88 pregnancies with symptomatic maternal hydronephrosis. Exclusion criteria were congenital urinary anomaly, a history of renal stones or any urology surgical intervention, oligohydramniosis and polyhydramniosis. Age at admission, gestational age, gravity, parity, side of dilatation, degree of dilatation, blood urea nitrogen (BUN), creatinine, WBC, complete urinary analysis and urine culture results were collected. Ethical approval was obtained from the Sevket Yilmaz Training and Research Hospital Ethical Committee. To determine maternal hydronephrosis we examined all the serial ultrasonographic evaluations and used the evaluation in which the result of dilatation was the largest. If there was a bilateral dilatation then the side of greater dilatation was taken into account. The grade of hydronephrosis was determined according to the maximal diameter. Patients were examined in three groups: group 1 was composed of patients having maximal calyceal diameter (MCD) of 5–10 mm (grade I); group 2 patients had MCD of 10–15 mm (grade II); and group 3 patients had MCD415 mm (grade III).
1054
S. Coban et al.
The result of obstetrical ultrasonography, fetal biometry, amniotic fluid index, gestational week at delivery, birth weight, type of delivery and sex of the baby was noted.
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 07/15/15 For personal use only.
Statistical analysis All statistical analysis was performed using SPSS version 15.0 (SPSS Inc., Chicago, IL). Suitability of the variables to normal distribution was examined by histograms and the Kolmogorov–Smirnov test. Descriptive statistics were evaluated as mean and standard deviation. Variables normally distributed were examined by an ANOVA test and the Tukey test and variables not normally distributed by the nonparametric Kruskal–Wallis test. Comparisons between two groups were done by the Mann–Whitney U-test, and Spearman’s analysis was used to examine correlations. A p value 0.05 was considered to indicate statistical significance.
Results Eighty-eight patients were diagnosed having hydronephrosis among 5800 (1.51%) singleton pregnancies. The mean age of the patients was 26.01 (18–37). There were 45 patients (51%) in group 1, 30 patients (34%) in group 2 and 13 patients (15%) in group 3. Thirty-two patients (48%) were primiparous. Seventy-one patients had hydronephrosis of the right kidney, 10 patients were bilaterally affected and seven patients had left kidney hydronephrosis. The mean age of the patients was 25.91 in group 1, 26.36 in group 2 and 25.53 in group 3 and there was no statistically significant difference between the groups (p ¼ 0.83). Gestational age at diagnosis was distributed as 23.41 weeks in group 1, 29.12 weeks in group 2 and 31.4 weeks in group 3 and there was a statistically significant difference between the three groups (p50.001). When we examined all the patients (n ¼ 88), the grade of maternal hydronephrosis was correlated with gestational age (p50.001, r ¼ 0.49). Figure 1. Mean birth weight of the study groups.
J Matern Fetal Neonatal Med, 2015; 28(9): 1053–1056
Estimated fetal weight (EFW) was correlated with the grade of hydronephrosis when diagnosed. (p ¼ 0.001, r ¼ 0.43). The mean birth weight of the babies was 3174 g (group 1), 3435 g (group 2) and 3145 g (group 3), which is shown in Figure 1. Although EFW values at the time of diagnosis were statistically significantly different in all groups (grade 1–3) of hydronephrosis (p ¼ 0.02) (Figure 2), there was no such difference between the grade of hydronephrosis and birth weights (p ¼ 0.1) (Table 1). There was also no significant difference between the study groups for age, gravity, parity, BUN and creatinine values, duration of pregnancy and sex of the delivered baby (p40.05). There were no mothers with impaired renal function and none of them experienced sepsis. Demographic, sonographic, biochemical and obstetric data are presented in Table 1. Eleven patients were diagnosed with urinary tract infection. Of these, seven patients had grade 1 hydronephrosis and four patients had grade 2 hydronephrosis. Urine cultures showed that there were eight patients with Escherichia coli infection, two patients with Klebsiella and only one patient with enterobacter infection. There were two patients treated with double J stent because their pain continued. Both of the patients had relief of the pain after the stent application. The mean gestational age at delivery was 38 weeks. Five of the patients delivered pre-term (537 weeks). Two delivered babies had birth weight 510th percentile (intrauterine growth retardation). Fifty-five (63%) patients delivered vaginally and 33 (37%) cases gave birth with cesarean section. Thirty-four delivered babies were female and 54 were male in gender. The average birth weight was 3265 g.
Discussion Asymptomatic dilatation of the upper urinary tract during pregnancy is seen in 90% of pregnancies. These asymptomatic dilatations can easily be treated in a conservative manner (analgesics, intravenous hydration, position changes at rest
Maternal hydronephrosis, fetal birth weight, fetal weight
DOI: 10.3109/14767058.2014.942631
1055
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 07/15/15 For personal use only.
Figure 2. EFW values of the study groups.
Table 1. Comparison of the general characteristics of the study groups.
Maternal age (years) GA (week) EFW (g) Fetal birth weight (g) GA at delivery (week) Gravidity Parity BUN (mg/dl) Creatinine (mg/dl)
Group 1 n ¼ 45 (51%)
Group 2 n ¼ 30 (34%)
Group 3 n ¼ 13 (15%)
Statistical significance (p values)
25.91 ± 4.73 23.41 ± 7.17 1127.32 ± 827.86 3174.85 ± 533.73 38.10 ± 2.34 1.82 ± 0.91 0.73 (0–2) 7.08 ± 3.40 0.55 ± 0.09
26.36 ± 4.51 29.12 ± 6.81 1817.32 ± 796.57 3435.22 ± 418.28 39.22 ± 1.11 1.71 ± 0.80 0.67 (0–3) 7.06 ± 2.22 0.53 ± 0.11
25.53 ± 3.47 31.40 ± 6.14 1964.82 ± 1032.21 3145.00 ± 524.56 38.29 ± 1.79 1.56 ± 0.72 0.56 (0–2) 7.90 ± 3.95 0.58 ± 0.12
0.83 50.001 0.02 0.12 0.21 0.82 0.86 0.77 0.85
EFW: Estimated fetus weight; GA: Gestational age; BUN: Blood urea nitrogen.
and antibiotics). However, in some cases the disease is symptomatic (0.2–3%) and these cases need to be treated, otherwise urinary infections and renal impairment that threaten the mother and baby can be seen [4]. The pathogenesis of maternal hydronephrosis is not well understood. There are two common theories: the first is that the ureters are pressured by the uterus and pelvic vessels at the pelvic entrance and the second theory is that progesterone is responsible for the dilatation via its relaxing effect on smooth muscles [7,10,11]. According to the mechanical theory, when the large uterus present more dilatation might be. The factors affecting uterus size are number of fetuses, size of the fetus and amount of amniotic fluid. In the present study, all the pregnancies were singleton and cases with oligohydramniosis and polyhydramniosis were excluded, so the only factor changing uterus size would be the size of the fetus. We found a correlation between EFW and dilatation grade, and there was a statistically significant difference in EFW in the three study groups. Hydronephrosis usually occurs in the second half of the pregnancy [6], progresses with time and is finished with termination of the pregnancy [12]. In this study, in agreement with the literature,
hydronephrosis was diagnosed on average in the 26th week [3] and dilatation of the right kidney was more common than the left [4,13]. Tsai et al. [14] studied 18 130 pregnancies and detected 93 (0.5%) symptomatic hydronephrosis cases at the 26th week of gestation. They found that hydronephrosis did not change the birth weight. Puskar et al. [4] examined 3400 pregnancies and found 104 (3%) had symptomatic hydronephrosis at the 29th week of gestation. Consistent with the literature, we detected 1.5% symptomatic hydronephrosis. We divided hydronephrosis into three groups and compared fetal development (birth weight) in these groups. We found that maternal hydronephrosis at different levels did not affect fetal development. Pre-term delivery was reported in 5–7% of cases with symptomatic hydronephrosis [15]. The incidence of intrauterine growth retardation (IUGR) in newborns was 3–7% in these patients [16]. In the present study, pre-term delivery and IUGR were 5 and 2%. We did not find increased pre-term delivery and IUGR. Maternal hydronephrosis has been shown to be easily treated [3,4,17]. We found that maternal hydronephrosis did not increase maternal or perinatal adverse outcomes.
1056
S. Coban et al.
In conclusion, we found there was no significant difference between birth weight at delivery.
Declaration of interest The authors have no conflicts of interest.
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 07/15/15 For personal use only.
References 1. Waltzer WC. The urinary tract in pregnancy. J Urol 1981;125: 271–6. 2. Cietak KA, Newton JR. Serial qualitative maternal nephrosonography in pregnancy. Br J Radiol 1985;58:399–404. 3. Fainaru O, Almog B, Gamzu R, et al. The management of symptomatic hydronephrosis in pregnancy. BJOG 2002;109: 1385–7. 4. Puskar D, Balagovic´ I, Filipovic´ A, et al. Symptomatic physiologic hydronephrosis in pregnancy: incidence, complications and treatment. Eur Urol 2001;39:260–3. 5. Brown MA. Urinary tract dilatation in pregnancy. Am J Obstet Gynecol 1991;164:642–3. 6. Rasmussen PE, Nielsen FR. Hydronephrosis during pregnancy: a literature survey. Eur J Obstet Gynecol Reprod Biol 1988;27: 249–59. 7. Clayton JD, Roberts JA. The effect of progesterone on ureteral physiology in a primate model. J Urol 1972;107:945–8. 8. Weiss JP, Hanno PM. Pregnancy and the urologist. AUA Update Ser 1990;9:266–71.
J Matern Fetal Neonatal Med, 2015; 28(9): 1053–1056
9. Eckford SD, Gingell JC. Ureteric obstruction in pregnancy – diagnosis and management. Br J Obstet Gynaecol 1991;98: 1137–40. 10. Van Wagenen G, Jenkins RH. Pyeloureteral dilatation of pregnancy after death of the fetus; an experimental study. Am J Obstet Gynecol 1948;56:1146–50. 11. Rubi RA, Sala NL. Ureteral function in pregnant women. 3. Effect of different positions and of fetal delivery upon ureteral tonus. Am J Obstet Gynecol 1968;101:230–7. 12. Sadan O, Berar M, Sagiv R, et al. Ureteric stent in severe hydronephrosis of pregnancy. Eur J Obstet Gynecol Reprod Biol 1994;56:79–81. 13. Swanson SK, Heilman RL, Eversman WG. Urinary tract stones in pregnancy. Surg Clin North Am 1995;75:123–42. 14. Tsai YL, Seow KM, Yieh CH, et al. Comparative study of conservative and surgical management for symptomatic moderate and severe hydronephrosis in pregnancy: a prospective randomized study. Acta Obstet Gynecol Scand 2007;86: 1047–50. 15. Beck S, Wojdyla D, Say L, et al. The worldwide incidence of preterm birth: a systematic review of maternal mortality and morbidity. Bull World Health Organ 2010;88:31–8. 16. Romo A, Carceller R, Tobajas J. Intrauterine growth retardation (IUGR): epidemiology and etiology. Pediatr Endocrinol Rev 2009; 6:332–6. 17. Zwergel T, Lindenmeir T, Wullich B. Management of acute hydronephrosis in pregnancy by ureteral stenting. Eur Urol 1996; 29:292–7.
ORIGINAL ARTICLE
Is there a relationship between the grade of maternal hydronephrosis and birth weight of the babies? Soner Coban1, Ismail Biyik2, Emin Ustunyurt3, Ibrahim Keles4, Muhammed Guzelsoy1, and Hakan Demirci5 J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 07/15/15 For personal use only.
1
Department of Urology, Sevket Yilmaz Education and Research Hospital, Bursa, Turkey, 2Department of Obstetrics and Gynecology, Karacabey State Hospital, Bursa, Turkey, 3Department of Obstetrics and Gynecology, Sevket Yilmaz Education and Research Hospital, Bursa, Turkey, 4 Department of Urology, Afyon Kocatepe University, Afyon, Turkey, and 5Department of Family Medicine, Sevket Yilmaz Education and Research Hospital, Bursa, Turkey Abstract
Keywords
Mild hydronephrosis may be present in upto 90% of pregnancies. The degree of hydronephrosis was determined by maximal calyceal diameter (MCD). The aim of this study is to investigate whether there is a relationship between grade of maternal hydronephrosis and birth weight of the babies. Subjects were examined in three groups: group 1 MCD of 5–10 mm (grade I), group 2 10–15 mm (grade II) and group 3 patients 415 mm (grade III). There were 45, 30, 13 patients in the groups, respectively. Estimated fetal weight (EFW) at the time that hydronephrosis was diagnosed, birth weight and duration of pregnancy were compared. The average birth weight of the babies was not statistically different in the three groups (p40.05), but there was a statistically significant difference in fetal weights at the time of diagnosis (p ¼ 0.02). The grade of maternal hydronephrosis does not affect the duration of pregnancy.
Fetal birth weight, fetal weight, maternal hydronephrosis
Introduction Pregnancy induced asymptomatic hydronephrosis is seen in 90% of pregnancies [1,2]. However, acute symptomatic dilatation of calixes, renal pelvis and ureters is seen in 0.2–3% of pregnancies [3,4]. Hydronephrosis is more commonly observed in primiparous pregnancies and dilatation is more prominent in the right kidney and ureter [4–6]. It frequently occurs in the second half of the pregnancy. The pathogenesis of the dilatation can be explained by two mechanisms: a mechanical pressure of the uterus on the ureters and relaxation of smooth muscles due to progesterone [4–7]. The explanation for three-fold more common dilatation in the right kidney compared to the left kidney are the dextra rotation of the enlarged uterus during pregnancy and a protective effect of the sigmoid colon for the left ureter from mechanical pressure [8,9]. The importance of mechanical pressure is supported by the fact that urinary system dilatation is more common in twin pregnancies and polyhydramniosis cases [9]. Fetal weight may increase the probability of a larger uterus. However, there are a limited number of studies on the relationship between
Address for correspondence: Ismail Biyik, MD, Department of Obstetrics and Gynecology, Karacabey State Hospital, Tavsanli Street 56, Road No: 4, Karacabey, Bursa 16700, Turkey. Tel: +905327867031. Fax: 0(224)6762450. E-mail: [email protected]
History Received 20 May 2014 Revised 18 June 2014 Accepted 4 July 2014 Published online 28 July 2014
maternal hydronephrosis and fetal weight. In the present study, we aimed to search the relationship between the grade of maternal hydroneprosis and birth weight of the babies.
Materials and methods This study was designed as a retrospective study and data of 5800 singleton pregnancies during the period January 2010 to June 2013 was analyzed. There were 88 pregnancies with symptomatic maternal hydronephrosis. Exclusion criteria were congenital urinary anomaly, a history of renal stones or any urology surgical intervention, oligohydramniosis and polyhydramniosis. Age at admission, gestational age, gravity, parity, side of dilatation, degree of dilatation, blood urea nitrogen (BUN), creatinine, WBC, complete urinary analysis and urine culture results were collected. Ethical approval was obtained from the Sevket Yilmaz Training and Research Hospital Ethical Committee. To determine maternal hydronephrosis we examined all the serial ultrasonographic evaluations and used the evaluation in which the result of dilatation was the largest. If there was a bilateral dilatation then the side of greater dilatation was taken into account. The grade of hydronephrosis was determined according to the maximal diameter. Patients were examined in three groups: group 1 was composed of patients having maximal calyceal diameter (MCD) of 5–10 mm (grade I); group 2 patients had MCD of 10–15 mm (grade II); and group 3 patients had MCD415 mm (grade III).
1054
S. Coban et al.
The result of obstetrical ultrasonography, fetal biometry, amniotic fluid index, gestational week at delivery, birth weight, type of delivery and sex of the baby was noted.
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 07/15/15 For personal use only.
Statistical analysis All statistical analysis was performed using SPSS version 15.0 (SPSS Inc., Chicago, IL). Suitability of the variables to normal distribution was examined by histograms and the Kolmogorov–Smirnov test. Descriptive statistics were evaluated as mean and standard deviation. Variables normally distributed were examined by an ANOVA test and the Tukey test and variables not normally distributed by the nonparametric Kruskal–Wallis test. Comparisons between two groups were done by the Mann–Whitney U-test, and Spearman’s analysis was used to examine correlations. A p value 0.05 was considered to indicate statistical significance.
Results Eighty-eight patients were diagnosed having hydronephrosis among 5800 (1.51%) singleton pregnancies. The mean age of the patients was 26.01 (18–37). There were 45 patients (51%) in group 1, 30 patients (34%) in group 2 and 13 patients (15%) in group 3. Thirty-two patients (48%) were primiparous. Seventy-one patients had hydronephrosis of the right kidney, 10 patients were bilaterally affected and seven patients had left kidney hydronephrosis. The mean age of the patients was 25.91 in group 1, 26.36 in group 2 and 25.53 in group 3 and there was no statistically significant difference between the groups (p ¼ 0.83). Gestational age at diagnosis was distributed as 23.41 weeks in group 1, 29.12 weeks in group 2 and 31.4 weeks in group 3 and there was a statistically significant difference between the three groups (p50.001). When we examined all the patients (n ¼ 88), the grade of maternal hydronephrosis was correlated with gestational age (p50.001, r ¼ 0.49). Figure 1. Mean birth weight of the study groups.
J Matern Fetal Neonatal Med, 2015; 28(9): 1053–1056
Estimated fetal weight (EFW) was correlated with the grade of hydronephrosis when diagnosed. (p ¼ 0.001, r ¼ 0.43). The mean birth weight of the babies was 3174 g (group 1), 3435 g (group 2) and 3145 g (group 3), which is shown in Figure 1. Although EFW values at the time of diagnosis were statistically significantly different in all groups (grade 1–3) of hydronephrosis (p ¼ 0.02) (Figure 2), there was no such difference between the grade of hydronephrosis and birth weights (p ¼ 0.1) (Table 1). There was also no significant difference between the study groups for age, gravity, parity, BUN and creatinine values, duration of pregnancy and sex of the delivered baby (p40.05). There were no mothers with impaired renal function and none of them experienced sepsis. Demographic, sonographic, biochemical and obstetric data are presented in Table 1. Eleven patients were diagnosed with urinary tract infection. Of these, seven patients had grade 1 hydronephrosis and four patients had grade 2 hydronephrosis. Urine cultures showed that there were eight patients with Escherichia coli infection, two patients with Klebsiella and only one patient with enterobacter infection. There were two patients treated with double J stent because their pain continued. Both of the patients had relief of the pain after the stent application. The mean gestational age at delivery was 38 weeks. Five of the patients delivered pre-term (537 weeks). Two delivered babies had birth weight 510th percentile (intrauterine growth retardation). Fifty-five (63%) patients delivered vaginally and 33 (37%) cases gave birth with cesarean section. Thirty-four delivered babies were female and 54 were male in gender. The average birth weight was 3265 g.
Discussion Asymptomatic dilatation of the upper urinary tract during pregnancy is seen in 90% of pregnancies. These asymptomatic dilatations can easily be treated in a conservative manner (analgesics, intravenous hydration, position changes at rest
Maternal hydronephrosis, fetal birth weight, fetal weight
DOI: 10.3109/14767058.2014.942631
1055
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 07/15/15 For personal use only.
Figure 2. EFW values of the study groups.
Table 1. Comparison of the general characteristics of the study groups.
Maternal age (years) GA (week) EFW (g) Fetal birth weight (g) GA at delivery (week) Gravidity Parity BUN (mg/dl) Creatinine (mg/dl)
Group 1 n ¼ 45 (51%)
Group 2 n ¼ 30 (34%)
Group 3 n ¼ 13 (15%)
Statistical significance (p values)
25.91 ± 4.73 23.41 ± 7.17 1127.32 ± 827.86 3174.85 ± 533.73 38.10 ± 2.34 1.82 ± 0.91 0.73 (0–2) 7.08 ± 3.40 0.55 ± 0.09
26.36 ± 4.51 29.12 ± 6.81 1817.32 ± 796.57 3435.22 ± 418.28 39.22 ± 1.11 1.71 ± 0.80 0.67 (0–3) 7.06 ± 2.22 0.53 ± 0.11
25.53 ± 3.47 31.40 ± 6.14 1964.82 ± 1032.21 3145.00 ± 524.56 38.29 ± 1.79 1.56 ± 0.72 0.56 (0–2) 7.90 ± 3.95 0.58 ± 0.12
0.83 50.001 0.02 0.12 0.21 0.82 0.86 0.77 0.85
EFW: Estimated fetus weight; GA: Gestational age; BUN: Blood urea nitrogen.
and antibiotics). However, in some cases the disease is symptomatic (0.2–3%) and these cases need to be treated, otherwise urinary infections and renal impairment that threaten the mother and baby can be seen [4]. The pathogenesis of maternal hydronephrosis is not well understood. There are two common theories: the first is that the ureters are pressured by the uterus and pelvic vessels at the pelvic entrance and the second theory is that progesterone is responsible for the dilatation via its relaxing effect on smooth muscles [7,10,11]. According to the mechanical theory, when the large uterus present more dilatation might be. The factors affecting uterus size are number of fetuses, size of the fetus and amount of amniotic fluid. In the present study, all the pregnancies were singleton and cases with oligohydramniosis and polyhydramniosis were excluded, so the only factor changing uterus size would be the size of the fetus. We found a correlation between EFW and dilatation grade, and there was a statistically significant difference in EFW in the three study groups. Hydronephrosis usually occurs in the second half of the pregnancy [6], progresses with time and is finished with termination of the pregnancy [12]. In this study, in agreement with the literature,
hydronephrosis was diagnosed on average in the 26th week [3] and dilatation of the right kidney was more common than the left [4,13]. Tsai et al. [14] studied 18 130 pregnancies and detected 93 (0.5%) symptomatic hydronephrosis cases at the 26th week of gestation. They found that hydronephrosis did not change the birth weight. Puskar et al. [4] examined 3400 pregnancies and found 104 (3%) had symptomatic hydronephrosis at the 29th week of gestation. Consistent with the literature, we detected 1.5% symptomatic hydronephrosis. We divided hydronephrosis into three groups and compared fetal development (birth weight) in these groups. We found that maternal hydronephrosis at different levels did not affect fetal development. Pre-term delivery was reported in 5–7% of cases with symptomatic hydronephrosis [15]. The incidence of intrauterine growth retardation (IUGR) in newborns was 3–7% in these patients [16]. In the present study, pre-term delivery and IUGR were 5 and 2%. We did not find increased pre-term delivery and IUGR. Maternal hydronephrosis has been shown to be easily treated [3,4,17]. We found that maternal hydronephrosis did not increase maternal or perinatal adverse outcomes.
1056
S. Coban et al.
In conclusion, we found there was no significant difference between birth weight at delivery.
Declaration of interest The authors have no conflicts of interest.
J Matern Fetal Neonatal Med Downloaded from informahealthcare.com by Nyu Medical Center on 07/15/15 For personal use only.
References 1. Waltzer WC. The urinary tract in pregnancy. J Urol 1981;125: 271–6. 2. Cietak KA, Newton JR. Serial qualitative maternal nephrosonography in pregnancy. Br J Radiol 1985;58:399–404. 3. Fainaru O, Almog B, Gamzu R, et al. The management of symptomatic hydronephrosis in pregnancy. BJOG 2002;109: 1385–7. 4. Puskar D, Balagovic´ I, Filipovic´ A, et al. Symptomatic physiologic hydronephrosis in pregnancy: incidence, complications and treatment. Eur Urol 2001;39:260–3. 5. Brown MA. Urinary tract dilatation in pregnancy. Am J Obstet Gynecol 1991;164:642–3. 6. Rasmussen PE, Nielsen FR. Hydronephrosis during pregnancy: a literature survey. Eur J Obstet Gynecol Reprod Biol 1988;27: 249–59. 7. Clayton JD, Roberts JA. The effect of progesterone on ureteral physiology in a primate model. J Urol 1972;107:945–8. 8. Weiss JP, Hanno PM. Pregnancy and the urologist. AUA Update Ser 1990;9:266–71.
J Matern Fetal Neonatal Med, 2015; 28(9): 1053–1056
9. Eckford SD, Gingell JC. Ureteric obstruction in pregnancy – diagnosis and management. Br J Obstet Gynaecol 1991;98: 1137–40. 10. Van Wagenen G, Jenkins RH. Pyeloureteral dilatation of pregnancy after death of the fetus; an experimental study. Am J Obstet Gynecol 1948;56:1146–50. 11. Rubi RA, Sala NL. Ureteral function in pregnant women. 3. Effect of different positions and of fetal delivery upon ureteral tonus. Am J Obstet Gynecol 1968;101:230–7. 12. Sadan O, Berar M, Sagiv R, et al. Ureteric stent in severe hydronephrosis of pregnancy. Eur J Obstet Gynecol Reprod Biol 1994;56:79–81. 13. Swanson SK, Heilman RL, Eversman WG. Urinary tract stones in pregnancy. Surg Clin North Am 1995;75:123–42. 14. Tsai YL, Seow KM, Yieh CH, et al. Comparative study of conservative and surgical management for symptomatic moderate and severe hydronephrosis in pregnancy: a prospective randomized study. Acta Obstet Gynecol Scand 2007;86: 1047–50. 15. Beck S, Wojdyla D, Say L, et al. The worldwide incidence of preterm birth: a systematic review of maternal mortality and morbidity. Bull World Health Organ 2010;88:31–8. 16. Romo A, Carceller R, Tobajas J. Intrauterine growth retardation (IUGR): epidemiology and etiology. Pediatr Endocrinol Rev 2009; 6:332–6. 17. Zwergel T, Lindenmeir T, Wullich B. Management of acute hydronephrosis in pregnancy by ureteral stenting. Eur Urol 1996; 29:292–7.
