- Email: [email protected]
Obstetric complications when the fetus has Potter's syndrome
Obstetric complications
when the fetus has
Potter’s syndrome I. Clinical
considerations
GRAEME
J.
NORMAN
RATTEN,
A.
BEISCHER,
F.R.C.S.(EDIN.), DENYS
W.
B.S., M.D.,
FORTUNE,
M.R.C.O.G. M.G.O.,
F.R.A.C.S.,
M.R.C.PATH.., Melbourne,
M.B.,
F.R.C.O.G.
M.B.,
M.R.C.P.(EDIN.),
F.R.C.P.A. Victoria,
Australia
Potter’s syndrome was found to occur once in 2,903 pregnancies, and in a series of 87 cases two thirds of the infants were boys. The main prenatal complications were antepartum hemorrhage (16 per cent), intrauterine death (27 per cent), breech presentation (40 per cent), and prolapse of the umbilical cord (7 per cent). A clinical diagnosis of placental insufficiency was seldom made before delivery, although 47 per cent of the infants were small for dates. Placental failure mainly occurred in late pregnancy, the incidence of fetal growth retardation being quadrupled after 36 weeks’ gestation. Complete absence of liquor was documented in IO cases, and the fetus had a tracheoesophageal fistula in the only one where there was an increased volume of amniotic fluid. The incidence of cesarean delivery was 10.3 per cent,
POTTER,~‘~ in 1946, described the distinctive facial characteristics found in association with renal agenesis and pulmonary hypoplasia. The main features she noted were abnormally large, low-set auricles deficient in cartilage, prominent epicanthic folds with increased space between the eyes, a conspic-
uous crease below the lower lip with recession of the chin, and slight flattening of the tip of the nose. Although Potter originally described these features in association with renal agenesis, she subsequently noted that they could be found with severe forms of renal dysplasia.3 Other features that may be present are broad, spadelike hands, musculoskeletal abnormalities including talipes, malformations of the genital tract, central nervous system, and other viscera. While intrauterine growth retardation is not a feature of such a major abnormality as Down’s syndrome,4, 5 oligohydramnios and low fetal birth weight are common in association with Potter’s syndrome.G Recently, one of our patients whose pregnancy was complicated by clinical signs of intrauterine growth retardation, breech presentation, and subnormal estriol excretion was delivered by ce-
From the Royal Women’s and Mercy Maternity Hospitals and the Department of Obstetrics and Gynaecology, University of Melbourne. Supported by a grant from the National Health and Medical Research Council of Australia. Received 1972. Revised Accepted
for publication October October
August
28,
19, 197.2. 19, 1972.
Reprint requests: Dr. Norman A. Be&her, Dept. of ObJGyn., Mercy Materncty Hospital, Clarendon St., East Melbourne, Australia, 3002. 890
Volume Number
113 7
Obstetric
complications
with
Potter’s
syndrome
891
5000
30
32
34 GESTATION
3s
36 IN
Fig. 1. Birth weight and duration of pregnancy in 85 cases of Potter’s 0, neonatal death. The tenth and ninetieth percentiles for birth weight age for infants born in this community are shown.1’
sarean section of an infant with Potter’s syndrome. This prompted us to review all cases of Potter’s syndrome seen at our hospitals, with special reference to the incidence of prenatal complications and fetal growth retardation. Material
and
methods
The case records of all patients delivered at the Royal Women’s and Mercy Maternity Hospitals, Melbourne, in whom pregnancy resulted in the birth of an infant proved at autopsy to have Potter’s syndrome, were reviewed. In addition, infants with Potter’s syndrome born in other hospitals but referred to our Departments of Pathology for autopsy were included. Results
and
comment
Incidence and fetal sex ratio. During
the 25 year period from 1947 to 1971, 87 infants with Potter’s syndrome were seen in our hospitals, 25 of these having been born elsewhere and referred for autopsy. The incidence of Potter’s syndrome was 1 in 2,903 confinements, there having been 179,957 patients delivered of their infants at our hospitals
40
42
WEEKS
syndrome. according
f, Stillbirth; to gestational
during these 25 years. This incidence is almost identical with that of 0.3 per 1,000 births quoted by Potter.” Of the 87 infants, 58 were boys; this 2: 1 male :female sex ratio is much lower than that noted by Potter,” whose series of 30 infants included only 4 girls. Prenatal complications. An unexpected finding was that fewer patients were rec,orded as having prenatal complications in the Potter’s syndrome series (54 per cent) than in the control series7 (62 per cent). A clinical diagnosis of placental insufficiency was made in only nine of the 87 patients, although oligohydramnios is regarded as the characteristic prenatal feature of Potter’s syndrome, and 47 per cent of the infants were small for dates (Fig. 1) . This finding emphasizes once again the fallibility of the clinician in the diagnosis
of growth
retardation
before
an
in-
fant is born.‘, ” The high incidence of antepartum hemorrhage was explained by there being a number of patients with a “heavy show” early in labor in the Potter’s syndrome series. None of the 14 patients with antepartum bleeding required a blood transfusion and in only
892
Ratten,
Fig. born
Beischer,
and
April 1. 1973 Am. J. Obstet. Gynecol.
Fortune
2. Ra .diograph at 35.4 weeks showing extreme al live by cesarean section at 36.5 weeks. The
4 was the cause of the hemorrhage found; 2 had mild abruptio placentae, and a marginal placenta previa was found in 2 others, one of whom required a cesarean section. We have no explanation for the finding that hypertension and pre-eclampsia were more common in the control series than in pregnancies where the fetus had Potter’s syndrome, particularly as the distribution of maternal age and parity was similar in the two groups. In both series these diagnoses were made during the prenatal period or when proteinuria and/or hypertension ( 14Q/ 90 or above) were detected for the first time during labor. The low incidence of prolonged pregnancy was expected, it being a feature of Potter’s
flexion of the fetal spine. patient had fibromyomas.
The
fe :tus was
syndrome that pregnancy frequently terminates spontaneously before term (Fig. 1) , The 3 patients with diabetes mellitus had only a mild form of the disease; 2 were treated by diet alone and one required oral hypoglycemic agents. There were 3 patients with uterine fibromyomas. Fetal distress. Prolapse of the umbilical cord occurred in 6 of the 87 pregnancies. In 3 of the 6 this complication was associated with breech presentation or fibromyomas, but our data seemed to indicate an increased risk of premature rupture of the membranes and cord prolapse when the fetus had Potter’s syndrome. Fetal death occurred before the onset of labor in 9 patients. In the other 78 patients,
Volume 115 1Number 7
the incidence of fetal distress in labor (a heart rate above 160 or below 120 per minute, the passage of meconium, or both) was low ( 21 per cent), being less than in the control series (28 per cent), although 13 fetuses died during labor or delivery. This surprising finding was explained by the high incidence of oligohydramnios. The presence of meconium-stained liquor was recorded in only 4 cases where the fetus was alive when labor began. In 10 cases complete absence of liquor was well documented (3 at cesarean section). In the only case where the liquor volume was copious, the infant was found at autopsy to have an associated tracheoesophageal fistula. Like other authors”, G we were disappointed at the lack of information in the case records regarding the color and volume of the amniotic fluid when the fetus had Potter’s syndrome. The incidence of cesarean section was 10.3 per cent or more than double the hospital figure of 4.7 per cent. The main indications for the 9 cesarean deliveries were cord prolapse (2) , fetal distress in labor (2)) previous uterine scar (2)) placenta previa ( 1) , uterine fibromyomas ( 1) , and breech presentation in an elderly primigravida ( 1) . Radiological appearances (Fig. 2). It has been statedI” that a radiograph taken in the upright position revealing complete collapse of the fetal spine into the pelvic area is pathognomonic of fetal death. However, other authors” have noted that extreme flesion of the fetal spine in association with oligohydramnios can give rise to this appearance when the fetus is alive. Prenatal x-rays were available in 4 of the 87 cases studied, and in 2 of these the fetus showed a marked flexion deformity of the upper thoracic spine. In one patient (Fig. 2) the possibility of fetal abnormality was considered when this radiological appearance was noted in association with clinical oligohydramnios. However, in the absence of any specific skeletal abnormality, cesarean section was performed when the clinical diagnosis of placental insufficiency was supported by the finding of subnormal estriol excretion.
Obstetric
complications
with
Potter’s
syndrome
893
Presentation at delivery. In this series there were 31 spontaneous breech deliveries, and in four of the nine patients who had cesarean sections, the fetus presented by the breech at the time of delivery. This extremely high incidence of breech presentation (40 per cent) was partly explained by the high incidence of prematurity, 23 of the patients being delivered of their infants before 34 weeks’ gestation (Fig. 1) . However it seemed likely that oligohydramnios was an important factor in determining breech presentation by preventing the fetus from turning in the normal way to adapt to the uterine shape in late pregnancy. Bain and Scott” found an even higher incidence of breech presentation at delivery (60 per cent) in their study of 50 cases of renal agenesis and severe urinary tract dysplasia. Time of fetal death. Forty of the 65 infants born alive died within 2 hours of birth and the longest period of survival was 28 hours. The clinical picture was always one of respiratory distress, with asphyxia as the cause of death. Life is too short with Potter’s syndrome for uremia to become a problem. We were surprised to find that in only 7 of the 87 infants was the diagnosis of Potter’s syndrome considered before autopsy was performed. The high stillbirth rate in this series (22 of 87, or 27 per cent) cannot be explained by Potter’s syndrome per se because pulmonary hypoplasia and renal agenesis are not incompatible with intrauterine existence. Birth weight was less than the tenth percentile according to maturity at deliveryl” in 71 per cent (15 of 21) of the stillborn infants and in 39 per cent (25 of 64) of the neonatal deaths (Fig. 1 i It therefore seemed that placental insufficiency was an important cause of intrauterine death in Potter’s syndrome, particularly when the fetus died before the onset of labor. Prolapse of the urnbilical cord caused 2 of the 13 fetal deaths which occurred in labor and 8 others were associated with breech delivery. The mother had diabetes mellitus in the only case in which a stillborn infant weighed more than
894
Ratten,
Beischer,
and
Fortune
+
30
32
34 GESTATION
36
38 IN
40
42
WEEKS
Fig. 3. Placental weight in 52 cases of Potter’s syndrome. The tenth and ninetieth percentiles for placental weight infants born in this community are shown.14
+, Stillbirth; according to
0, neonatal gestational
death. age for
Birth weight and the incidence of prematurity. In this series birth weight was
Fig. 4. Nodular
amnion 3 mm. diameter on fetal in Potter’s syndrome.
nodosum lesions of 1 to surface
of the
placenta
the ninetieth percentile for the period of gestation (Fig. 1). Fetoplacental function was estimated by 24 hour urinary excretion of estriol in 3 patients whose infants were stillborn, and was normal in all cases; in 2 death was due to cord prolapse and in the third estriol excretion was normal 3 weeks before death occurred in labor at 33 weeks.
documented in 85 of the 87 cases. Forty infants (47 per cent) weighed less than the tenth percentile, and 74 (86 per cent) weighed less than the fiftieth percentile for the period of gestation at birth.l? We have previously reported that intrauterine growth retardation (birth weight below the tenth percentile for dates) was a highly significant feature of major fetal malformations with the exception of Down’s syndrome.13 However, the incidence of 47 per cent found in the present study was the highest we have encountered with any malformation other than anencepha1y.l” Macafee and colleagues9 reported that in infants with congenital heart disease the incidence of growth retardation was doubIed when there was an associated extracardiac defect. However, in the present study the incidence of fetal growth retardation was the same in the group of infants with Potter’s syndrome alone (27 cases) as in the larger group of 60 cases in which the fetus had additional malformations. It was found that
Volume Number
115 7
fetal growth retardation in Potter’s syndrome became commoner in the last 4 weeks of pregnancy, as though placental failure began to occur at this time (Fig. 1). In this series growth retardation was present in 15 per cent (6 of 39) of infants born before 36 weeks and in 73 per cent (34 of 46) of those born at 36 weeks and thereafter. Moreover, the incidence of stillbirths was doubled after 36 weeks’ gestation. Bain and ScoV also noted that infants with renal agenesis were of approximately the expected birth weight up to 34 weeks. These authors considered that fetal growth and proper placental development and function may normally be dependent on progressive distention of the uterus by amniotic fluid. In the present series 60 per cent (52 of 87) of patients came into spontaneous labor before 37 weeks, which is more than 4 times the incidence in the over-all hospital populations. This confirms previous reports that Potter’s syndrome is associated with prematurity.‘, ‘9 6 Placental weight. In the present study placental weight was less than the tenth percentile according to maturity at deliveryI in 20 of the 52 cases (38 per cent) in which data were available. As was seen with fetal birth weight, the placentas were more likely to be small for dates after 36 weeks’ gestation (Fig. 3). The mother had diabetes mellitus in one of the 2 cases in which placental weight exceeded the ninetieth percentile. In this series amnion nodosum was noted in 12 of the 52 placentas referred to our
Obstetric
complications
with
Potter’s
syndrome
895
departments of pathology for examination. Fig. 4 shows the appearance of these miliarylike nodules on the fetal surface of the placenta. These lesions are considered to be specifically related to oligohydramnios, Ihe nodules being masses of desquamated fetal epidermal cells.” Associated abnormalities. At autopsy all 87 infants in this series were described as having the facies characteristic of Potter’s syndrome. Pulmonary hypoplasia was present in all cases, and there was often interstitial emphysema and pneumothorax due to attempts at resuscitation. The nature of the abnormalities of the urinary tract were bilateral renal agenesis (44)) bilateral renal dysplasia with cyst formation (31) , and renal hypoplasia (5)) and in 7 cases one kidney was absent, the other showing evidence of hypoplasia or dysplasia. Apart from the above abnormalities there were associated malformations in 60 of the 87 cases. In 38 there was some form of talipes, which is considered to be a pressure effect due to oligohydramnios.” It was common for there to be either absence or malformation of organ systems in the midline of the pelvis and perineum; there were five infants with an imperforate anus, and 14 of the 29 girls had major anomalies of organs arising from the Miillerian ducts. None of the mothers in this study was known to have given birth to abnormal infants in previous pregnancies. We wish to thank the medical staffs of our hospitals for their cooperation in this study and Miss A. Scarfe for preparation of the illustrations.
REFERENCES
1. 2.
Potter, E. L.: J. Pediatr. 29: 68, 1946. Potter, E. L.: AM. J. OBSTET. GYNECOL. 51: 885, 1946. 3. Potter, E. L.: Pathology of the Fetus and the Newborn, ed. 1, Chicago, 1952, Year Book Medical Publishers, Inc., p. 363. 4. Macafee, J., Fortune, D. W., Brown, J. B., and Be&her, N. A.: Obstet. Gynecol. 36: 735, 1970. 5. Kucera, J.: Obstet. Gynecol. 38: 551, 1971.
6. 7.
8.
9.
Bain, A. D., and Scott, J. S.: Br. Med. J. 1: 841, 1960. Beischer, N. A., Bhargava, V. I,.: Brown, J. B., and Smith, M. A.: J. Obstet. Gynaecol. Br. Commonw. 75: 1024, i968. MacLeod. S. C.. Brown. T. B.. Beischer. N. A.. and Smih, M.’ A.: ALit. j%. Z. J. ‘Obstet: Gynaecol. 7: 25, 1967. Macafee, J., Beischer, N. A., and Fortune, D. W.: AM. J. OBSTET. GYNECOL. 110: 891, 1971.
896
10. 11. 12.
Rotten,
Be&her,
and
Fortune
Tager, S. N.: Am. J. Roentgenol. 67: 106, 1952. Kent, B. K., Rubin, S., and Dann, D. S.: AM. J. OBSTET. GYNECOL. 74: 1106, 1957. Kitchen, W. H.: Aust. Paediatr. J. 4: 29, 1968.
13.
14.
Macafee, C. A. J., Be&her, N. A., Brown, J. B., and Fortune, D. W.: Aust. N. Z. J. Obstet. Gynaecol. 12: 71, 1972. Kitchen, W. H.: Aust. Paediatr. J. 4: 103, 1968.
when the fetus has
Potter’s syndrome I. Clinical
considerations
GRAEME
J.
NORMAN
RATTEN,
A.
BEISCHER,
F.R.C.S.(EDIN.), DENYS
W.
B.S., M.D.,
FORTUNE,
M.R.C.O.G. M.G.O.,
F.R.A.C.S.,
M.R.C.PATH.., Melbourne,
M.B.,
F.R.C.O.G.
M.B.,
M.R.C.P.(EDIN.),
F.R.C.P.A. Victoria,
Australia
Potter’s syndrome was found to occur once in 2,903 pregnancies, and in a series of 87 cases two thirds of the infants were boys. The main prenatal complications were antepartum hemorrhage (16 per cent), intrauterine death (27 per cent), breech presentation (40 per cent), and prolapse of the umbilical cord (7 per cent). A clinical diagnosis of placental insufficiency was seldom made before delivery, although 47 per cent of the infants were small for dates. Placental failure mainly occurred in late pregnancy, the incidence of fetal growth retardation being quadrupled after 36 weeks’ gestation. Complete absence of liquor was documented in IO cases, and the fetus had a tracheoesophageal fistula in the only one where there was an increased volume of amniotic fluid. The incidence of cesarean delivery was 10.3 per cent,
POTTER,~‘~ in 1946, described the distinctive facial characteristics found in association with renal agenesis and pulmonary hypoplasia. The main features she noted were abnormally large, low-set auricles deficient in cartilage, prominent epicanthic folds with increased space between the eyes, a conspic-
uous crease below the lower lip with recession of the chin, and slight flattening of the tip of the nose. Although Potter originally described these features in association with renal agenesis, she subsequently noted that they could be found with severe forms of renal dysplasia.3 Other features that may be present are broad, spadelike hands, musculoskeletal abnormalities including talipes, malformations of the genital tract, central nervous system, and other viscera. While intrauterine growth retardation is not a feature of such a major abnormality as Down’s syndrome,4, 5 oligohydramnios and low fetal birth weight are common in association with Potter’s syndrome.G Recently, one of our patients whose pregnancy was complicated by clinical signs of intrauterine growth retardation, breech presentation, and subnormal estriol excretion was delivered by ce-
From the Royal Women’s and Mercy Maternity Hospitals and the Department of Obstetrics and Gynaecology, University of Melbourne. Supported by a grant from the National Health and Medical Research Council of Australia. Received 1972. Revised Accepted
for publication October October
August
28,
19, 197.2. 19, 1972.
Reprint requests: Dr. Norman A. Be&her, Dept. of ObJGyn., Mercy Materncty Hospital, Clarendon St., East Melbourne, Australia, 3002. 890
Volume Number
113 7
Obstetric
complications
with
Potter’s
syndrome
891
5000
30
32
34 GESTATION
3s
36 IN
Fig. 1. Birth weight and duration of pregnancy in 85 cases of Potter’s 0, neonatal death. The tenth and ninetieth percentiles for birth weight age for infants born in this community are shown.1’
sarean section of an infant with Potter’s syndrome. This prompted us to review all cases of Potter’s syndrome seen at our hospitals, with special reference to the incidence of prenatal complications and fetal growth retardation. Material
and
methods
The case records of all patients delivered at the Royal Women’s and Mercy Maternity Hospitals, Melbourne, in whom pregnancy resulted in the birth of an infant proved at autopsy to have Potter’s syndrome, were reviewed. In addition, infants with Potter’s syndrome born in other hospitals but referred to our Departments of Pathology for autopsy were included. Results
and
comment
Incidence and fetal sex ratio. During
the 25 year period from 1947 to 1971, 87 infants with Potter’s syndrome were seen in our hospitals, 25 of these having been born elsewhere and referred for autopsy. The incidence of Potter’s syndrome was 1 in 2,903 confinements, there having been 179,957 patients delivered of their infants at our hospitals
40
42
WEEKS
syndrome. according
f, Stillbirth; to gestational
during these 25 years. This incidence is almost identical with that of 0.3 per 1,000 births quoted by Potter.” Of the 87 infants, 58 were boys; this 2: 1 male :female sex ratio is much lower than that noted by Potter,” whose series of 30 infants included only 4 girls. Prenatal complications. An unexpected finding was that fewer patients were rec,orded as having prenatal complications in the Potter’s syndrome series (54 per cent) than in the control series7 (62 per cent). A clinical diagnosis of placental insufficiency was made in only nine of the 87 patients, although oligohydramnios is regarded as the characteristic prenatal feature of Potter’s syndrome, and 47 per cent of the infants were small for dates (Fig. 1) . This finding emphasizes once again the fallibility of the clinician in the diagnosis
of growth
retardation
before
an
in-
fant is born.‘, ” The high incidence of antepartum hemorrhage was explained by there being a number of patients with a “heavy show” early in labor in the Potter’s syndrome series. None of the 14 patients with antepartum bleeding required a blood transfusion and in only
892
Ratten,
Fig. born
Beischer,
and
April 1. 1973 Am. J. Obstet. Gynecol.
Fortune
2. Ra .diograph at 35.4 weeks showing extreme al live by cesarean section at 36.5 weeks. The
4 was the cause of the hemorrhage found; 2 had mild abruptio placentae, and a marginal placenta previa was found in 2 others, one of whom required a cesarean section. We have no explanation for the finding that hypertension and pre-eclampsia were more common in the control series than in pregnancies where the fetus had Potter’s syndrome, particularly as the distribution of maternal age and parity was similar in the two groups. In both series these diagnoses were made during the prenatal period or when proteinuria and/or hypertension ( 14Q/ 90 or above) were detected for the first time during labor. The low incidence of prolonged pregnancy was expected, it being a feature of Potter’s
flexion of the fetal spine. patient had fibromyomas.
The
fe :tus was
syndrome that pregnancy frequently terminates spontaneously before term (Fig. 1) , The 3 patients with diabetes mellitus had only a mild form of the disease; 2 were treated by diet alone and one required oral hypoglycemic agents. There were 3 patients with uterine fibromyomas. Fetal distress. Prolapse of the umbilical cord occurred in 6 of the 87 pregnancies. In 3 of the 6 this complication was associated with breech presentation or fibromyomas, but our data seemed to indicate an increased risk of premature rupture of the membranes and cord prolapse when the fetus had Potter’s syndrome. Fetal death occurred before the onset of labor in 9 patients. In the other 78 patients,
Volume 115 1Number 7
the incidence of fetal distress in labor (a heart rate above 160 or below 120 per minute, the passage of meconium, or both) was low ( 21 per cent), being less than in the control series (28 per cent), although 13 fetuses died during labor or delivery. This surprising finding was explained by the high incidence of oligohydramnios. The presence of meconium-stained liquor was recorded in only 4 cases where the fetus was alive when labor began. In 10 cases complete absence of liquor was well documented (3 at cesarean section). In the only case where the liquor volume was copious, the infant was found at autopsy to have an associated tracheoesophageal fistula. Like other authors”, G we were disappointed at the lack of information in the case records regarding the color and volume of the amniotic fluid when the fetus had Potter’s syndrome. The incidence of cesarean section was 10.3 per cent or more than double the hospital figure of 4.7 per cent. The main indications for the 9 cesarean deliveries were cord prolapse (2) , fetal distress in labor (2)) previous uterine scar (2)) placenta previa ( 1) , uterine fibromyomas ( 1) , and breech presentation in an elderly primigravida ( 1) . Radiological appearances (Fig. 2). It has been statedI” that a radiograph taken in the upright position revealing complete collapse of the fetal spine into the pelvic area is pathognomonic of fetal death. However, other authors” have noted that extreme flesion of the fetal spine in association with oligohydramnios can give rise to this appearance when the fetus is alive. Prenatal x-rays were available in 4 of the 87 cases studied, and in 2 of these the fetus showed a marked flexion deformity of the upper thoracic spine. In one patient (Fig. 2) the possibility of fetal abnormality was considered when this radiological appearance was noted in association with clinical oligohydramnios. However, in the absence of any specific skeletal abnormality, cesarean section was performed when the clinical diagnosis of placental insufficiency was supported by the finding of subnormal estriol excretion.
Obstetric
complications
with
Potter’s
syndrome
893
Presentation at delivery. In this series there were 31 spontaneous breech deliveries, and in four of the nine patients who had cesarean sections, the fetus presented by the breech at the time of delivery. This extremely high incidence of breech presentation (40 per cent) was partly explained by the high incidence of prematurity, 23 of the patients being delivered of their infants before 34 weeks’ gestation (Fig. 1) . However it seemed likely that oligohydramnios was an important factor in determining breech presentation by preventing the fetus from turning in the normal way to adapt to the uterine shape in late pregnancy. Bain and Scott” found an even higher incidence of breech presentation at delivery (60 per cent) in their study of 50 cases of renal agenesis and severe urinary tract dysplasia. Time of fetal death. Forty of the 65 infants born alive died within 2 hours of birth and the longest period of survival was 28 hours. The clinical picture was always one of respiratory distress, with asphyxia as the cause of death. Life is too short with Potter’s syndrome for uremia to become a problem. We were surprised to find that in only 7 of the 87 infants was the diagnosis of Potter’s syndrome considered before autopsy was performed. The high stillbirth rate in this series (22 of 87, or 27 per cent) cannot be explained by Potter’s syndrome per se because pulmonary hypoplasia and renal agenesis are not incompatible with intrauterine existence. Birth weight was less than the tenth percentile according to maturity at deliveryl” in 71 per cent (15 of 21) of the stillborn infants and in 39 per cent (25 of 64) of the neonatal deaths (Fig. 1 i It therefore seemed that placental insufficiency was an important cause of intrauterine death in Potter’s syndrome, particularly when the fetus died before the onset of labor. Prolapse of the urnbilical cord caused 2 of the 13 fetal deaths which occurred in labor and 8 others were associated with breech delivery. The mother had diabetes mellitus in the only case in which a stillborn infant weighed more than
894
Ratten,
Beischer,
and
Fortune
+
30
32
34 GESTATION
36
38 IN
40
42
WEEKS
Fig. 3. Placental weight in 52 cases of Potter’s syndrome. The tenth and ninetieth percentiles for placental weight infants born in this community are shown.14
+, Stillbirth; according to
0, neonatal gestational
death. age for
Birth weight and the incidence of prematurity. In this series birth weight was
Fig. 4. Nodular
amnion 3 mm. diameter on fetal in Potter’s syndrome.
nodosum lesions of 1 to surface
of the
placenta
the ninetieth percentile for the period of gestation (Fig. 1). Fetoplacental function was estimated by 24 hour urinary excretion of estriol in 3 patients whose infants were stillborn, and was normal in all cases; in 2 death was due to cord prolapse and in the third estriol excretion was normal 3 weeks before death occurred in labor at 33 weeks.
documented in 85 of the 87 cases. Forty infants (47 per cent) weighed less than the tenth percentile, and 74 (86 per cent) weighed less than the fiftieth percentile for the period of gestation at birth.l? We have previously reported that intrauterine growth retardation (birth weight below the tenth percentile for dates) was a highly significant feature of major fetal malformations with the exception of Down’s syndrome.13 However, the incidence of 47 per cent found in the present study was the highest we have encountered with any malformation other than anencepha1y.l” Macafee and colleagues9 reported that in infants with congenital heart disease the incidence of growth retardation was doubIed when there was an associated extracardiac defect. However, in the present study the incidence of fetal growth retardation was the same in the group of infants with Potter’s syndrome alone (27 cases) as in the larger group of 60 cases in which the fetus had additional malformations. It was found that
Volume Number
115 7
fetal growth retardation in Potter’s syndrome became commoner in the last 4 weeks of pregnancy, as though placental failure began to occur at this time (Fig. 1). In this series growth retardation was present in 15 per cent (6 of 39) of infants born before 36 weeks and in 73 per cent (34 of 46) of those born at 36 weeks and thereafter. Moreover, the incidence of stillbirths was doubled after 36 weeks’ gestation. Bain and ScoV also noted that infants with renal agenesis were of approximately the expected birth weight up to 34 weeks. These authors considered that fetal growth and proper placental development and function may normally be dependent on progressive distention of the uterus by amniotic fluid. In the present series 60 per cent (52 of 87) of patients came into spontaneous labor before 37 weeks, which is more than 4 times the incidence in the over-all hospital populations. This confirms previous reports that Potter’s syndrome is associated with prematurity.‘, ‘9 6 Placental weight. In the present study placental weight was less than the tenth percentile according to maturity at deliveryI in 20 of the 52 cases (38 per cent) in which data were available. As was seen with fetal birth weight, the placentas were more likely to be small for dates after 36 weeks’ gestation (Fig. 3). The mother had diabetes mellitus in one of the 2 cases in which placental weight exceeded the ninetieth percentile. In this series amnion nodosum was noted in 12 of the 52 placentas referred to our
Obstetric
complications
with
Potter’s
syndrome
895
departments of pathology for examination. Fig. 4 shows the appearance of these miliarylike nodules on the fetal surface of the placenta. These lesions are considered to be specifically related to oligohydramnios, Ihe nodules being masses of desquamated fetal epidermal cells.” Associated abnormalities. At autopsy all 87 infants in this series were described as having the facies characteristic of Potter’s syndrome. Pulmonary hypoplasia was present in all cases, and there was often interstitial emphysema and pneumothorax due to attempts at resuscitation. The nature of the abnormalities of the urinary tract were bilateral renal agenesis (44)) bilateral renal dysplasia with cyst formation (31) , and renal hypoplasia (5)) and in 7 cases one kidney was absent, the other showing evidence of hypoplasia or dysplasia. Apart from the above abnormalities there were associated malformations in 60 of the 87 cases. In 38 there was some form of talipes, which is considered to be a pressure effect due to oligohydramnios.” It was common for there to be either absence or malformation of organ systems in the midline of the pelvis and perineum; there were five infants with an imperforate anus, and 14 of the 29 girls had major anomalies of organs arising from the Miillerian ducts. None of the mothers in this study was known to have given birth to abnormal infants in previous pregnancies. We wish to thank the medical staffs of our hospitals for their cooperation in this study and Miss A. Scarfe for preparation of the illustrations.
REFERENCES
1. 2.
Potter, E. L.: J. Pediatr. 29: 68, 1946. Potter, E. L.: AM. J. OBSTET. GYNECOL. 51: 885, 1946. 3. Potter, E. L.: Pathology of the Fetus and the Newborn, ed. 1, Chicago, 1952, Year Book Medical Publishers, Inc., p. 363. 4. Macafee, J., Fortune, D. W., Brown, J. B., and Be&her, N. A.: Obstet. Gynecol. 36: 735, 1970. 5. Kucera, J.: Obstet. Gynecol. 38: 551, 1971.
6. 7.
8.
9.
Bain, A. D., and Scott, J. S.: Br. Med. J. 1: 841, 1960. Beischer, N. A., Bhargava, V. I,.: Brown, J. B., and Smith, M. A.: J. Obstet. Gynaecol. Br. Commonw. 75: 1024, i968. MacLeod. S. C.. Brown. T. B.. Beischer. N. A.. and Smih, M.’ A.: ALit. j%. Z. J. ‘Obstet: Gynaecol. 7: 25, 1967. Macafee, J., Beischer, N. A., and Fortune, D. W.: AM. J. OBSTET. GYNECOL. 110: 891, 1971.
896
10. 11. 12.
Rotten,
Be&her,
and
Fortune
Tager, S. N.: Am. J. Roentgenol. 67: 106, 1952. Kent, B. K., Rubin, S., and Dann, D. S.: AM. J. OBSTET. GYNECOL. 74: 1106, 1957. Kitchen, W. H.: Aust. Paediatr. J. 4: 29, 1968.
13.
14.
Macafee, C. A. J., Be&her, N. A., Brown, J. B., and Fortune, D. W.: Aust. N. Z. J. Obstet. Gynaecol. 12: 71, 1972. Kitchen, W. H.: Aust. Paediatr. J. 4: 103, 1968.