
Potter Sequence
Philippe Jeanty, MD, PhD
& Sandra R Silva, MD
Several entities use the eponym Potter:
1) Potter syndrome, now renamed either
oligohydramnios sequence or bilateral renal agenesis (BRA)
depending on whether the cause of the
syndrome (BRA) or the mechanism is referred to.
2) Potter syndrome Type I is now referred to as Autosomal recessive polycystic kidney disease
3) Potter syndrome Type II is now referred to as Renal dysplasia
4) Potter syndrome Type III is now referred to as Autosomal dominant polycystic kidney disease

WHAT IS THE KIDNEY FUNCTION IN THE BODY?
All the body processes produce waste materials, which if allowed to accumulate could poison the body. Excretion is the process of cleaning this waste from the body, the skin excretes water and salt, the lungs excrete carbon- dioxide and water vapor, and the kidneys excretes urine. The kidneys are found at the back of the abdominal (or stomach) cavity in the region known as the small of the back. The normal adult kidney is about 7 cm wide and 12 cm long. A thin tube called the ureter connects the kidney with the bladder. Urine forms in the kidney and is passed down this tube into the bladder. The kidneys also receive blood from the heart which is full of oxygen in order to help the kidneys function and when this blood has been used it has to be passed back into the blood stream to be refilled with oxygen. The kidneys are composed of a vast network of tubes which are all vital to the proper function of each kidney.
WHAT IS POTTERS SYNDROME?
Potters Syndrome is the term used to describe the total absence or malformation of infant kidneys. The condition gets it name from Edith Potter who first described the condition in 1946 at the Chicago Lying-In Hospital in Chicago. Prior to this there had been several isolated studies done on infants with the condition, some even date back as far as the sixteen hundreds but up until this study it was presumed that the condition was extremely rare. Dr. Potters investigation concentrated only on total Renal Agenesis (absent kidneys) but since then the name has been extended to any condition where the kidneys fail to develop fully.
WHAT IS A SYNDROME?
A syndrome is a collection of associated problems, which relate to one primary problem. In simple terms with Potters Syndrome the main problem is that the kidneys are missing but because of this other problems arise. The kidneys cannot produce the fluid to develop the lungs so therefore the infant’s lungs are underdeveloped as a result. Also related to the lack of fluid are the physical features of Potters Syndrome. The infant is so tightly packed in the womb that the limbs may not form properly and the face may show certain features such as a flattened nose and chin etc. All of the above go to make up a syndrome which are directly connected to the one major problem, which is the absence or malformation of the kidneys.
WHAT DID DR. POTTERS STUDY SHOW?
The first study was carried out on 20 infants
who had died over a ten-year period. In the group there were 17 males and
3 females babies. Of the 19 available maternal histories the mother’s ages
ranged from 18 to 39 years giving an average age of 24 years. Two of these
women had had previous abortions, only two had more than two previous pregnancies
one of whom had 11 children. Nineteen of the mothers were white and one
was Negro. There was therefore one common link between the mothers with
regard to age, race or number of pregnancies.
She also noted that these babies
were more likely to be born live rather than stillborn. In the group fetal
death occurred prior to labour in one infant, during labour in six and
after birth in thirteen. The length of life varied from 25 minutes to 11
hours 15 minutes giving an average life span of 1 hour 38 minutes.
Of the 16 babies where the gestation
of pregnancy had been record the number of weeks varied from 26 weeks to
40 weeks giving an average delivery time of about 32.5 weeks.
Dr. Potter was unable to establish
the amount of amniotic fluid present with each baby and therefore was unable
to establish the important link between the kidneys and the production
of the fluid. This was only discovered and confirmed later. The cause of
the death was mainly associated to the malformation of the lungs. There
children also showed similar facial features such as the wide set eyes,
a slightly compressed nose, low set flat ears and also a compression of
the chin. Other physical features were clubbed feet and some with club
hands. With the female babies it was noted that their genitalia were extremely
under developed where as with males the development for the most part had
been perfectly normal.
SUMMARY: Dr. Potter concluded that the incidence of this condition was somewhere between 4 and 7 deaths per thousand deaths in newborn infant. She also noted that there was no relation to maternal age or to method of delivery or to complication during pregnancy. The infants were predominately male. The lungs of the infants were all severely underdeveloped or hypoplastic and that all the infants showed characteristic facial expressions. Prior to post mortem examination only 8 of the infants were believed to have died because of malformations.
WHAT DO WE NOW KNOW ABOUT POTTERS SYNDROME?
OCCURRENCE RATE: The incidence of Potters Syndrome is said to be somewhere between 1 in 2000 and 1 and 5000 the average would suggest to be on occurrence rate of approximately 1 in 4000 births.
SEX LINKAGE: Potters Syndrome is predominately a male condition with an occurrence rate of approximately 65% - 80% male babies.
TIME FACTOR: complete Renal Agenesis (or absence of kidneys) must occur before 31 days of fetal development.
CAUSE OF DEATH: The primary cause of infant death is respiratory insufficiency. The fetal kidneys are responsible for the production of the amniotic fluid in the womb. The baby then inhales the fluid into its lungs which in turn causes the lungs to grow. When the kidneys are absent or not working the vital fluid is not produced and therefore the lungs cannot develop properly and therefore when the baby is born it is unable to breath properly.
ABSENT KIDNEYS: These infants could for up to three or four days with absent or redundant kidneys if the lungs had any other way to develop but because this is not possible the maximum life span for a baby with renal agenesis would seem to be about 12 hours. Where there is some kidney development with a little kidney function the life span could be slightly longer but the child would probably need the aid of a respirator and probably dialysis.
KIDNEY TRANSPLANT: With regards to kidney
transplant this would appear to be a futile venture where total renal agenesis
(absent kidneys) is present as it would be difficult to ascertain what
other necessary tubes and material had failed to develop and there would
also be the problem of the under development of the trying to keep the
infant alive while waiting for a transplant and the child might also require
a lung transplant. There would be great difficulty in getting donors, which
would have to be children of the same age, and then blood types etc would
have to be matched which would be a very difficult task.
In the extremely rare cases where partial
kidney development has been sufficient to develop the lungs to a reasonable
stage these very fortunate babies can then be put on respirators and then
on dialysis and if the babies survive treatment at a later stage in early
childhood the child can then go forward for transplant. But these children
would probably be slower than normal children would. This however would
be the exception to the rule as the vast majority of Potters Syndrome babies
die at birth or shortly afterwards.
TYPES OF POTTERS SYNDROME: The most common form of Potters Syndrome is the total absence of kidneys. There are however varying degrees of the condition. Potters Syndrome can vary from the total absence to malformations of the kidneys as with polycystic kidneys to the development of only one of the kidneys to just the under-development of both kidneys. Therefore, renal agenesis (or absent of kidneys) would be referred to as pure Potters Syndrome and any other development would be referred to as a variation of potters Syndrome.
AT WHAT STAGE CAN POTTERS SYNDROME BE DIAGNOSED?
If total absents of kidneys is going
to happen it must happen prior to 31 days of fetal development. By twelve
weeks of pregnancy the baby has all its organs present but due to the size
of the organs the kidneys development would be difficult to access at that
stage. It is possible however to make a diagnosis from 14 weeks but
more likely to be made from about 18 weeks. If the diagnosis is made
this early the mother will be brought for continual assessment during her
pregnancy to see if there is any change or development. On scanning the
first thing that the doctor will notice will be the extreme lack of amniotic
fluid, this will suggest to him that there maybe a kidney problem and he
will then do all possible to establish whether or not the kidneys have
developed. This lack of fluid referred to as Oligohydramnios. If an indept
fetal assessment is carried out on the baby preferably at a later date
in pregnancy it will establish to a 95% certainly that the kidneys are
absent. A further test can be done again using a scan to detect if there
is any kidney function. With this test the doctor inserts a thin needle
into the womb through the mothers abdomen, a procedure very similar to
amniocentesis and then can inject fluid into the baby’s abdomen and track
by scan to see if the fluid will travel to the baby’s kidneys. On completion
of this the doctor should be about 99% certain of his diagnosis, leaving
a 1% margin for error.
In some cases where the mother is not
scanned during pregnancy the condition may go completely undetected until
after birth. At birth all babies are graded on color, capacity to breathe,
weight, size and general strength. With Potters Syndrome babies it will
be visible that the child has a severe respiratory problem and may show
some of the facial and physical features associated with the syndrome.
If the mother has not scanned the diagnosis might only be made by post
– mortem examination. Unfortunately because the only symptom before birth
is the absence of fluid Potters Syndrome can be hard to diagnose before
birth and will often go undetected as the rest of the fetal development
is normal and at birth the babies are usually quite a healthy weight. The
opposite of Oligohydramnio is Polyhydramnio which is too much fluid and
is related to water on the infants brain.
WHY DO POTTERS SYNDROME BABIES SHOW SIMILAR
PHYSICAL FEATURES?
When the amniotic fluid is missing
the baby lives in a very tightly packed enviroment and therefore will demonstrate
very compressed features. Normally the baby is surrounded by the fluid,
which allows freedom of movement, and of growth. It helps in the development
of the babies muscular and skeletal system. Inhaling the fluid is also
vital to the development of the baby’s lungs. The fluid prevents fetal
parts growing unevenly and being pressed against the wall of the uterus
or womb. With Potters Syndrome the babies face and head will be squashed
in the womb and thus lead to the very flat, low-set ears. The nose and
chin will also show compression and the nose can sometimes is described
as beaked. The muscles will also be under developed as the baby will not
have much room for exercise and the feet maybe turned- in otherwise described
as clubfeet. The baby may also have underdevelopment of the hands,
which can be described as club-hands.
HOW CAN THE BABY SURVIVE IN THE WOMB WITH
POTTERS SYNDROME?
In the womb the baby’s life is dependent
on the functions of the placenta. The placenta acts like a life-support
system and filters products and food from the mother to the baby and then
back out into the mothers system for disposal. The amniotic fluid, which
is normally a straw colored and clear substance, consists of 99% water
with small amounts of protein, glucose, and salt and also contains shed
cells from the baby. The baby’s urine is mostly water because the mother’s
kidneys are functioning via the placenta for the baby disposing of any
waste products. Therefore the baby can survive without its kidneys as long
as the placenta is functioning normally. The problems for the baby will
more than likely only show after birth.
WHAT IS THE RISK OF A REOCCURANCE OF THE
POTTERS SYNDROME?
In the vast majority of cases this
is an isolated abnormality and in this respect it is unlikely to recur
in the same family. Statistically however once you have had one Potters
Syndrome baby the risk of a reoccurrence of some kind of kidney defect
is put at about 3%. In a few cases there maybe an abnormality of one kidney
from either parent in which case the risk of having Potters Syndrome again
may be up to 10%. Rarer again is when there is a genetic link to the syndrome
when the risk maybe as high as 1 in 4.
Thankfully the bulk of cases of Potters
Syndrome has no parental link and therefore is unlikely to ever happen
again. The most difficult issue to deal with is that with these cases there
is no explanation as to why it occurred in the first place. It has not
yet been discovered just what is responsible for this syndrome. It could
be related to chromosome activity or D.N.A. but why it is just the kidneys
which do not grow or which malforms is anybody’s guess.
SHOULD PARENTS HAVE GENETIC COUNSELING?
This is a personal choice. Genetic counseling
is available through your doctor or G.P. In most cases you
will need to be referred to a genetic counselor by your doctor. Both parents
will probably need to have their chromosomes checked by a blood test. They
will also require scans of their kidneys and will also need as much information
as possible on their baby i.e. post mortem results and chromosome test
if carried out. Genetic counseling can ascertain the individual couples
risk and help them make informed choices for the future.

This website was created by
Michele
(In Memory of her daughter
Gabriela Lael)
for the
Potter's
Syndrome Forum