Obstetrical James Mandell, Judy A. Estroff,

Structural Detected

MD MD

Bruce Beryl

#{149} #{149}

R. Blyth, MD R. Benacerraf,

B

Index terms: Fetus, genitouninary system, 856.877 #{149} Fetus, US studies, 856.1298 #{149} Genitourinary system, abnormalities, 856.877 #{149} Hydronephnosis, 856.8772 #{149} Kidney, dysplasia, 856.8779 178:193-196

of the

ECAUSE

increased for

(US)

last

Postnatal

of the

period. Sonogmaphic sults of follow-up natal studies, and

with over

treatment,

as

anxious

well

as

and mepostwere

expectant

PATIENTS

urinary

tertiary-bevel

center

of

and

February 1989. Each patient was scanned at least once by one of the authors (B.R.B.) using an Acuson 128 (Acuson, Mountain

View,

Calif)

3.5-MHz

examined another

variable-focus

transducer.

at least once author

examinations findings

with

patients

a

were

in the presence

of

and number

of

(J.M.).

diagnosis (ie,

were noted. The the type of anomaly;

presence of renal, involvement; and fluid)

were

scans

for all cases

tected

scanner

Most

recorded

hydronephrosis

specific the

uretemal, and bladder the volume of amniotic prospectively.

The

of sonographically

were

AP

diam-

of pyelectasis

renal

de-

reviewed

outto de-

associ-

abnormalities.

who were a suspect(on the ba-

scanning or finding of an

anomaly during sonography for an unrelated indication during this penod. The number of examinations per patient ranged from one to 13, with a mean of 2.3. The gestational age at the time of the first examination ranged mean

from of 26.

15 to 40 weeks, The most common

was

with

a suspected

anomaly

based

US studies

on

a refer-

genitoresults

of

(93 patients included routine

ab-

nal age, maternal disease (ie, diabetes), maternal fibroids, on Rh incompatibility. Four (2%) patients were meferred with a family (sibling, parent,

or extended family member) history of a genitouninany tract anomaly. The fetal US findings were classified into several groups (Table 1). Hydronephrosis of the abnormalities,

accounted for occurring

87% in 154

patients (Figs 1, 2). The remaining fetal diagnoses arrived at with US included multicystic dysplastic kidney in

in

Abbreviation:

case.

limits

significant

sis of results of previous family history) on the

retrospectively by one of the authors (B.R.B.), and the antemoposteriom (AP) diameter of the renal pelvis was measured each

the

deter-

screening for size and dates of gestation (36 patients [20%]) or during US examination of amniotic fluid (amniocentesis) (12 patients [7%]). Thinty-two (18%) of the patients were mefemred for screening due to abnormal a-fetopnotein levels, advanced mater-

diagnostic 1987

and

was

between

[53%]). Other categories normalities noted during

of all patients

February

outcome

Theme were 177 patients examined because of either ed genitouninany anomaly

previous

abnormalities

obstetric

between

US ex-

studies,

RESULTS

urinary

METHODS

the records

for fetal

the

with

ral diagnosis

parents.

AND

We examined

evaluated

for

counseling

overall

Correlation

termine

ated

diag-

evaluated to establish guidelines fetal monitoring, evaluation, and

included

etem of the renal pelvis and postnatal come in regard to surgery was used

fetal a 2-year

findings sonogmaphy, treatment

The

mined.

care

fetus

follow-up umoradiologic

surgery.

few

prenatal

monitoring

The referring

From the Division of Urology, Department of Surgery, the Children’s Hospital, 300 Longwood Ave. Boston, MA 02115; and the Departments of Radiology and Obstetrics and Gynecology, Brigham and Women’s Hospital, Boston. Received January 3, 1990; revision requested February 27; final revision received August 24; accepted September 5. Address reprint requests to J.M. C RSNA, 1991

in the

appropriate

177 patients diagnosed umologic abnormalities

at one

MD

aminations,

fetal-ma-

number of feknown on susanomalies has

markedly

The

and

the

B. Retik,

use

for

nosed with such anomalies, as well as the timing, place of delivery, postnatal evaluation, and treatment, are not always evident. In addition, the threshold of fetal renal pyelectasis, particularly in the second trimester, resulting in significant renal disease in the neonate is controversial. To address some of these issues, we retrospectively analyzed the records of

US US 1

Alan

#{149}

ever-growing

temnal screening, the tuses identified with pected genitourinary years.

MD

Defects

of ultrasound

US

1991;

A. Peters,

Genitourinary in Utero’

Fetal genitourinary anomalies are detected with increasing frequency due to the large numbers of fetuses that undergo screening ultrasonography (US) for nonspecific indications. One hundred seventy-seven patients were evaluated for fetal urinary abnormalities over a 2-year period. Fetal hydronephrosis accounted for 154 (87%) of the cases, with the remaining diagnoses including multicystic dysplastic kidney, autosomal recessive polycystic kidney disease, and renal agenesis or hypodysplasia. Ureteropelvic junction obstruction was the most common postnatal anatomic abnormality (29%), with a large number of cases of prenatally diagnosed hydronephrosis resolving either prenatally (33%) or postnatally (24%). Prenatal US findings were retrospectively analyzed with regard to the degree of hydronephrosis at different stages of gestation. Data showed that there is a gradual rise in anteroposterior renal pelvic diameter during gestation and that there is a correlation between this diameter and the ultimate renal outcome in regard to surgical repair. This information can provide guidance in making recommendations to parents and physicians.

Radiology

#{149} Craig MD

Ultrasound

10 patients

(6%),

AP

=

autosomal

reces-

anteroposterior.

193

Figure 1. Transverse (a) and longitudinal (b) views show mild pyelectasis. Postnatal follow-up revealed degree of mild pyelectasis (6 and 5 mm, respectively)

of fetal

kidneys

normal kidneys, does not have

at 30 weeks

gestation

suggesting that this clinical significance.

sive cystic disease in five (3%), bilatenal renal agenesis on severe dysgenesis (Potter syndrome) in four (2%), unilateral renal agenesis in two (1%), prune-belly syndrome in two (1%), and unilateral renal hypodysplasia and echogenic kidney in one patient each (1%). We divided those patients with hydnonephnosis into several subcategories (Table 1) on the basis of the pres-

ence of unilateral or bilateral involvement, a duplicated collecting system, an enlarged bladder, tures of prune-belly syndrome 3-5). At the time of the first amination in those patients

lateral

or unilateral

without

duplication,

patients

of less

or fea(Figs US exwith bi-

theme

vealed

than

were

20 to 30 weeks,

gesta-

61 from

from tion,

30 weeks to term. During gestamost patients with hydroneremained in 23%

(2%)

Results of postnatal those newborns with

are shown in Table junction obstruction common

with

a large

ing either 6 demonstrates

diameter

this

pelvic

diameter at risk

mous

bladder

dexes ibility

(1) suggesting underwent

tomy.

Although

and 194

surgery

prenatal

favorable,

weeks, 8 mm at 20-30 1 cm from 30 weeks on. Radiology

#{149}

fluid

5 mm

weeks,

with

and

fetal

return

at

ly and soon those fetuses

ease

was

universally

fetus

in-

meyersvesicos-

findings

were

of amniotic

viability,

died. with

fetal during

urinary

the

labor born

mother

at 21 premature-

The outcome in bilateral cystic dis-

fatal

as well.

Figure 3. Longitudinal view of the shows a duplex collecting system. both pants of the renal pelvis are dilated, upper system shows greaten dilatation as well as unetemectasis (arrows).

left

bilatan enor-

potential open fetal initial

with

one

46,XY

fetal

went into premature weeks; the fetus was

the was

mild

of the up clini-

disease,

A 19-week,

Figure pelvic

representing for

period.

mesolv-

hydronephmosis in whom postnatal surgery was performed gradually increased throughout gestation. The group 15-20

and

with

with severe oligohydmamnios, eral hydmonephrosis, and

the

of cases

with

kidney

obstruction followed

fatal. Only was undertaken

or postnatally. that the renal

in patients

fetal

oligohydramnios, genitouninany

was uniformly intervention

abnormality,

number

right junction is being

with severe or without

of

2. Unetenopelvic represented

normal

of fetal kidneys shows greater (10 mm) than the follow-up me-

The overall outcome in all patients with hydronephrosis is shown in Table 3. The outcome in those patients

or wons-

follow-up hydronephnosis

anatomic pre-

39

stable (66%), with and the remainder

showing improvement ening (9%).

most

and

Transverse view second trimester on the left (LT) (7 mm). Postnatal

umeteropelvic kidney, which cabby.

45

20 weeks

2.

in the late pyelectasis right (Rfl

hydmonephrosis

tion,

phnosis resolution

Figure

DISCUSSION The finding of a fetal abnormality at maternal screening examination represents both an opportunity and a responsibility for the involved cians. Few other clinical situations provide such a window of visibility that permits the study of the natural evolution and progress of fetal renal structure and function. When we started the program of pediatric urologic involvement in the fetal ing program, we had few guidelines on which to base follow-up studies ultimate treatment. In this study, the overall outcome was favorable except for those fetuses with oligohydramnios or bilateral cystic disease. Six percent died of unrelated causes. We continue to be ex-

January

1991

not

done

immediately

after

birth

(un-

less there is reason to suspect bladder outlet obstruction), since early postnatal oliguria can cause an underestimation of the degree of obstructive hydronephrosis (2). We give those newborns with moderate or severe hydronephmosis antibiotic suppression therapy pending completion of the evaluation. Other studies have evaluated the threshold of fetal hydronephrosis me-

sulting

b. Figure dilatation

4.

(a) Longitudinal of the renal pelves

pelves was under this a significant tended

in the

view of both fetal kidneys at 16 weeks as well as calicectasis. Although the

the critical abnormality.

same

diameter for surgery (b) The fetal bladder

patient,

suggesting

posterior

gestation measurement

shows bilateral of the renal

(5 mm), the presence of calicectasis made and posterior urethra (arrows) were disurethral

valves.

study

tmemely

selective

mare fetuses cal

intervention

Those the

marked the

be

surgi-

indicated.

are characterized

presence

by

178

urologic

abnormality.

identify

those

who

hydro-

a significant How

do?

First,

we

serial

mine whether the initial findings are persistent. Often, with growth of the fetus, the apparent dilatation diminishes with time. From the perspective of the fetal evaluation, most prospective parents can be counseled that

cystic,

pamenchyma;

“favor-

electrolyte levels and a normal

learned

Number

#{149}

that

a great

1

num-

their

newborn

tively with postnatally.

can

important

can

hydronephro-

of severely

are

apparent

have

bilateral

kanyotype. After careful discussion, many families have chosen elective termination of such a fetus.

Volume

with

do not

examinations

renal

have

of fetuses

nephrosis

oligohydram-

able” fetal urinary and osmolality (1);

We

ben

of severe

absence

echogenic

the

in utero

might

fetuses

nios; sis;

in identifying

for whom

be evaluated

to deter-

elec-

US at about 1 to 2 weeks The US examination is

significant

neo-

by Gnignon

et al were

in the

late second to third trimester (3). Other studies have correlated in utero hydronephrosis with postnatal outcome; however, the number of patients in each study was small (39 in the series of Anger et al [4] and 25 in that of Kleiner et al [5]). Hoddick et al (6) studied minimal fetal renal pyelectasis and found that it occurred in 23.5% of kidneys in a series of 17 patients. The threshold measurement of the renal pelvis in their study was 3 mm, which by our criteria probably represents a normal kidney. We have found that the degree of dilatation in utero is likely to be greater than that is observed postnatally and that significant progression of in utero pyelectasis is uncommon. This is in agreement with the find-

ings

Figure 5. Composite image of the fetal bladder and upper urinary tract in a third-trimester fetus shows distention of the fetal bladder (open arrow), moderately severe (>15 mm) hydronephnosis (barge solid arrows), and umetemectasis (small solid arrows). This fetus underwent surgery as a newborn.

in clinically

natal disease (3-7). In most, persistent postnatal renal abnormalities have been observed when the fetal renal pelvis measures at least 10 mm in AP diameter. Most fetuses in the

of previous

series

(5), but

the

reason is unclear. We agree with Arger et al (4) that renal pelves larger than 10 mm in AP diameter after 25 weeks represent risk for renal disease in the neonate. Our experience, however, with the younger fetuses shows that this threshold may be lower, probably in pant because the kidneys are smaller earlier in pregnancy. The AP diameter of the renal pelvis rep-

resenting

the

group

at risk

for sum-

gery rose from 5 mm at 15-20 weeks to 8 mm at 20-30 weeks and 1 cm thereafter. One obvious weakness of this study is that it was a retrospective analysis based on postnatal outcome. Prospective studies based on

the

current

We still follow-up

findings

are in progress.

recommend obtaining pre- or postnatal renal

one

sonogram, even when pyelectasis is mild, to detect any progression in utero, since this occurred in 10% of our cases. Large

numbers

of fetuses

are

now

undergoing sonogmaphy for many different obstetric indications; relatively few examinations are done to Radiology

195

#{149}

look

for a specific

genitouninary

anomaly.

Fetal

abnormalities

are

usu-

ally detected when not otherwise suspected (7,8). In this study, those patients initially seen for a suspected genitouninary anomaly were in the minority. It is imperative to determine when such findings indicate significant problems and which fetuses are likely to require treatment as neonates.

prenatal

We

have

categorized

US findings

overall

diagnoses

gestation.

in terms and

hydronephrosis

with

It is hoped

in this

mine

which

quine

postnatal

report

that

will

fetuses

regard

are

to

stages the

help likely

monitoring

QESTAT)ONALAGE

of

at different

ings

F of

find-

deter-

2.

3.

196

Radiology

operated

4.

5.

MS. et al. congenital

hydronephrosis. ii. Prognostic criteria and selection for treatment. J Pediatr Sung 1985; 20:376-381. Laing FC, Burke VD, Wing VW, Jeffrey RB Jr. Hashimoto B. Postpartum evaluation of fetal hydronephrosis: optimal timing for follow-up sonography. Radiology 1984; 152:423-424. Grignon A, Filion R, Filiatrault D, et al. Urinary tract dilatation in utero: classifica-

#{149}

gestational

periods on, 0

during

pregnancy.

not operated

U

on.

to me-

References Click PL, Harrison MR. Colbus Management of the fetus with

Figure 6. Relationship of prenatal renal pelvic diameters in patients requiring postnatal surgery for hydmonephrosis at various

or surgi-

cal correction. This information can provide much-needed guidance in making recommendations to parents and physicians. U

1.

(.)

6.

tion and clinical applications. Radiology 1986; 160:645-647. Anger PH, Coleman BC, Mintz MC, et at. Routine fetal genitouninary screening. Radiotogy 1985; 156:485-489. Kleiner B, Callen PW, Filly RA. Sonographic analysis of the fetus with ureteropelvic junction obstruction. AJR 1987; 148:359-363. Hoddick WK, Filly RA. Mahony BS, Callen

PW. 7.

8.

Minimal

fetal renal

pyelectasis.

J Ul-

trasound Med 1985; 4:85-89. Cruenwald SM, Crocker EF, Walker AC, Trudinger BJ. Antenatal diagnosis of unnary tract abnormalities: correlation of ultrasound appearance with postnatal diagnosis. Am J Obstet Cynecol 1984; 148:278283. Helm I, Persson P. Prenatal diagnosis of urinary tract abnormalities by ultrasound. Pediatrics 1986; 78:879-882.

January

1991

Structural genitourinary defects detected in utero.

Fetal genitourinary anomalies are detected with increasing frequency due to the large numbers of fetuses that undergo screening ultrasonography (US) f...
949KB Sizes 0 Downloads 0 Views