Table 1

 Do well infants born with an isolated single umbilical artery need investigation?

CitationStudy groupLevel of evidenceOutcomeKey resultsComments
Thummala et al (1998)204 infants with isolated single umbilical artery from 7 studies where in infants with isolated single SUA were investigated for occult renal malformationsMeta-analysis of case series (level 3a)Detection of associated malformations33/204 infants had occult renal malformations Mean 16.2%, (95% CI for mean 7.7% to 25.6%; Median 5.3%; (range 0% to 33%) 15/204 had major anomalies (7.4%) The most frequent renal anomaly of significance was vesico -ureteric refluxNone of the case series included had controls Only articles in English language were included in the meta-analysis There is no data on other organ system malformations
Bourke et al (1993)Prospective case series of 112 infants with isolated SUA from 35 000 deliveries. Case detection was by clinical examination of the placenta All cases underwent screening renal ultrasonography. Those with abnormalities were further investigated with a micurating cystourethrogram (MCUG) and had monthly urine cultures for 6 monthsCase series (level 4)Urinary tract anomalies detected on ultrasonogram19/112 had some form of renal anomaly (16.9%). In 8 of them the abnormalities were significant (7.1%). 5/8 had VUR. 3/8 infants had UTI within the first 5 months of ageIncluded in Thummala paper Does not specify if deliveries were consecutive No control group
Leung and Robson (1989)Case series of 159 infants detected to have SUA from records of 56 919 deliveries during a 20 year period. 27 of these 159 infants who had an isolated SUA underwent renal imaging.Case series (level 4)Urinary tract anomalies detected on ultra sonogram or intravenous pyelography (IVP)5/27 had abnormal renal imaging (18.5%) One each had multicystic kidneys, hypoplastic kidneys, horse shoe kidneys, hydronephrosis and bifid ureterIncluded in Thummala paper Retrospective review Screening tool not the same for all cases No control group
Feingold et al (1964)Prospective case series. 32 infants detected to have SUA among 6080 deliveries. Three infants died in the neonatal period. IVP was performed on 24 of the 29 survivors without overt renal malformationsCase series (level 4)Urinary tract anomalies detected on IVP8/24 infants; (33.3%) had renal malformation In half of them malformations were severe These included massive reflux with hydronephrosis,absent kidney, horse shoe kidney and severe bladder neck obstructionIncluded in Thummala paper Not all cases were investigated No control group
Vlietinck et al (1972)Prospective case series without controls. 29 infants were detected to have SUA among 2572 deliveries. 4 were stillborn and 2 died in the neonatal period. 19 of the 23 infants who had an isolated SUA were investigatedCase series (level 4)Urinary tract anomalies detected on IVP1/19 infants (5.3%) had an abnormality—complete duplication of the left renal pelvisIncluded in Thummala paper Not all cases were investigated No control group
Harris and Van Leeuwen (1968)Prospective case series without controls. 11 infants detected to have isolated SUA among 2800 consecutive deliveriesCase series (level 4)Urinary tract anomalies detected on IVPNone of the infants had renal malformations (0/11)Included in Thummala paper Small sample size No control group
VanLeeuwen et al (1967)Prospective case series without controls. 4 infants were detected to have isolated SUA among 2000 consecutive deliveriesCase series (level 4)Urinary tract anomalies detected on IVPNone of the infants had renal malformations (0/4)Included in Thummala paper Small sample size No control group
Johnsonbaugh (1973)Prospective case series. 8 infants of 1152 deliveries had isolated SUA. Only 5/8 infants were investigatedCase series (level 4)Detection occult renal anomalies by IVP, transumbilical artery aortography to detect aortic malformations and chromosomal analysisNone of the 5 investigated infants had renal, aortic malformations or any chromosomal abnormalityIncluded in Thummala paper Not all cases were investigated Small sample size No control group