pregnancy in patients with end - stage renal disease ( esrd ) is rare , and kidney disease before pregnancy is associated with poor fetal outcome .
however , the outcome of pregnancy in dialysis patients has been much improved , and the overall rate of successful fetal outcome is reported to be 76% ( 1 ) .
this is mainly due to a multidisciplinary approach that incorporates intensive dialysis and aggressive management of anemia and hypertension .
autosomal dominant polycystic kidney disease ( adpkd ) is the most common inherited renal disease , and approximately half of the patients progress to esrd by age of 60 ( 2 ) . with regard to pregnancy , fertility
is not affected by adpkd in patients with normal renal function ( 3 , 4 ) . however , as kidney cysts grow , hypertension and deterioration of kidney function develop , which adversely affect pregnancy .
in addition , massively enlarged kidneys may occupy the abdominal and pelvic cavities , preventing the normal growth of placenta and fetus .
we present a case of successful pregnancy in an adpkd patient on hemodialysis ( hd ) .
she started hd 3 times a week after 3 yr of her initial diagnosis . at the time of presentation
, she was normotensive and had been prescribed aspirin ( 100 mg daily ) , multivitamins , calcium - based phosphate binders , and erythropoietin ( 1,000 units every hd session ) .
her dry weight was 53.3 kg and interdialytic weight gain was 1.5 - 2.5 kg .
she was confirmed to be 8 weeks pregnant by pelvic ultrasound and beta - hcg test .
the physical examination revealed a blood pressure ( bp ) of 137/85 mm hg and a regular heart rate of 107 beats per minute .
laboratory findings at presentation were as follows : hemoglobin ( hb ) of 10.4 g / dl ; hematocrit ( hct ) 31.5% ; blood urea nitrogen ( bun ) 56.9 mg / dl ; serum creatinine ( cr ) 9.0 mg / dl ; total protein 5.9 g / dl ; serum albumin 3.7 g / dl ; serum calcium 9.3 mg / dl ; serum phosphorus 3.3 mg / dl ; potassium 5.5 mm / l ; and normal liver function .
the computed tomography scan taken 2 yr ago showed bilaterally enlarged kidneys filled with numerous renal cysts along with only a few liver cysts ( fig .
she was managed by a multidisciplinary team approach to optimize the patient and fetal outcomes .
firstly , the risk of pregnancy in a dialysis patient and the need for intensive dialysis were discussed with her family .
secondly , our team evaluated the risk of stunted intrauterine fetal growth by her massively enlarged kidneys .
we considered a unilateral nephrectomy at the second trimester to secure the intraabdominal space , but the risk was determined to outweigh the benefits in this case .
finally , genetic counseling about the fetus 's risk of inheriting adpkd and prenatal genetic diagnosis was provided but declined by the patient . at 10 weeks gestation , hd prescription
was changed to 4-hr treatments 4 - 5 times a week , and a predialysis bun less than 50 mg / dl was targeted . throughout pregnancy , predialysis bun
her bp was well controlled without any antihypertensive medication : systolic bp remained at 110 - 140 mmhg and diastolic was consistently at 60 - 80 mmhg .
erythropoietin doses were adjusted to target a maternal hb between 10 - 11 g / dl .
the median dose was 18,000 iu / week ( range , 5,000 - 26,000 iu / week ) during gestational weeks 12 - 36 .
in addition , 100 mg intravenous iron sucrose was administered every session during gestational weeks 19 - 22 .
the follow - up data of dry weight , predialysis bun and hb level are shown in fig .
routine fetal karyotyping was performed at 16 gestational weeks , but mutation screening was not performed . at 34.5 weeks of gestation , the membrane ruptured during hd , and vaginal delivery was performed without any complications .
she delivered a healthy female weighing 2,100 g. one week after delivery , the patient was hospitalized for 5 days because of postpartum cardiomyopathy .
previous studies suggested pregnancy in women with adpkd and normal kidney function can result in a favorable outcome .
( 3 ) studied fertility and pregnancy complications between patients with polycystic kidneys ( n=76 ) and a control group ( no polycystic kidney ) ( n=61 ) of women at risk of adpkd .
they found no significant distinction between the 2 groups with regard to fertility , spontaneous abortion , stillbirth , or urinary tract infection ( 3 ) .
another study showed that overall fetal complication rates were not significantly different between women with and without adpkd ( 4 ) . on the contrary ,
affected women with preexisting renal failure and hypertension developed various complications and were associated with poor fetal outcome .
other risk factors for fetal complications include maternal age > 30 yr and development of preeclampsia ( 4 ) .
landesman and sherr ( 5 ) suggested a classification of pregnant women with adpkd based on severity of renal disease .
the patient in this case would be classified into group c , which refers to patients in renal failure secondary to advanced pkd .
( 6 ) first described a successful pregnancy in a patient with group c disease , and other cases have also been reported ( 6 - 9 ) .
prophylactic hemodialysis was needed in 1 case ( 8) , and in another case series , we found a pkd patient who underwent nocturnal hd , which is seldom performed in korea ( 10 ) . with this background
, we sought to determine the best way to secure fetal survival and a good maternal outcome .
first , the management of ckd - related complications and the hd schedule were reviewed .
pregnant women with a favorable outcome were found to have lower predialysis bun levels compared to those with adverse fetal outcomes ( 11 ) .
it is recommended to increase the hemodialysis frequency ( usually 4 - 6 sessions / week ) to maintain a predialysis bun below 50 mg / dl ( 12 ) .
this provides a less uremic environment for the fetus , allows better control of volume status and bp , and permits the mother a more liberal diet .
it also reduces the risk of intradialytic hypotension , which may be associated with fetal distress and premature labor ( 12 ) . increasing the dialysis dose prolongs gestation , resulting in higher birth weights and a better chance of fetal survival ( 13 ) .
hypertension is the most frequently reported maternal complication in hd patients , occurring in 42%-80% of women ( 14 ) .
both the rate of fetal survival and birth weights were lower in hypertensive pregnant patients compared to normotensive patients .
maternal dry weight and interdialytic weight gain should be regularly evaluated and adjusted according to changes in fetal growth ( 12 ) .
a lower third trimester hematocrit was associated with risk of an adverse fetal outcome and low birth weight ( 11 ) .
erythropoietin dose needs to be increased by approximately 50% in order to maintain a target hemoglobin level of 10 - 11 g / dl ( 13 ) .
another important area of concern for adpkd patients is the mass effect of huge kidneys and/or a massive polycystic liver
. this can cause chronic pain and compression of adjacent organs , resulting in indigestion , gastroesophageal reflux , malnutrition , and ascites ( compression of ivc or portal vein ) .
although adpkd does not affect fertility , pregnancy in patients with large kidneys at an advanced stage of renal failure has not been reported .
the patient in this case had a measured kidney volume of about 6 l which is 30-fold larger than normal .
fortunately , the patient 's liver size was normal with only a few small cysts , and she had no symptoms related to a mass effect . moreover , abdominal muscles during pregnancy can adapt to increased space requirements by increasing the intra - abdominal volume under the influence of various hormones , such as relaxin .
this case illustrates that even a very large kidney volume has no significant adverse effect on pregnancy .
lastly , the risk of congenital anomalies and inheritance of mutant pkd genes should be evaluated .
prenatal genetic diagnosis can be offered by obtaining fetal dna through chorionic villus sampling or amniocentesis .
however , demand for prenatal diagnosis for elective abortion seems to be low , as in our case , and only 4% of women with adpkd would terminate a pregnancy if they knew the inheritance status ( 15 ) .
although pregnancy remains risky in adpkd patients with esrd undergoing long - term hemodialysis , outcomes can be improved by optimizing management through a multidisciplinary team of nephrologists , obstetricians , and neonatal care specialists . intensified dialysis , proper anemia management , and improved
preconception counseling is needed in all women on dialysis because most of the pregnancies reported were unplanned .
 recent advances in dialysis and a multidisciplinary approach to pregnant patients with advanced chronic kidney disease provide a better outcome . 
 a 38-yr - old female with autosomal dominant polycystic kidney disease ( adpkd ) became pregnant . 
 she was undergoing hemodialysis ( hd ) and her kidneys were massively enlarged , posing a risk of intrauterine fetal growth restriction . by means of intensive hd and optimal management of anemia , pregnancy was successfully maintained until vaginal delivery at 34.5 weeks of gestation . 
 we discuss the special considerations involved in managing our patient with regard to the underlying adpkd and its influence on pregnancy.graphical abstract 