| Abstract|| |
Pregnancy is an infrequent event in women at child bearing age who are on chronic dialysis therapy. To evaluate the incidence and the various therapeutic interventions on the outcome of pregnancy we studied 80 women on chronic hemodialysis. There were six pregnancies in five patients over six years of follow up (1988 -1994). To reduce the risk factors associated with pregnancy, we tried to control the blood pressure to a level below l50/90mmHg, to increase the duration and frequency of hemodialysis, to keep the hemoglobin level in the blood above 80 gm/L and to minimize the risk of bleeding by the usage of regional heparinization during the dialysis sessions. Also we kept predialysis BUN below 25mmol/L and used bicarbonate based dialysate. Two pregnancies ended with spontaneous abortion, three with premature delivery and only one had delivery on time. Two of the infants born alive died later during the neonatal period, while the other two are still alive - one, a girl, is now 5 years old and the other, a boy, is now 1 ˝ years old. None of our pregnant women died. We conclude that pregnancy is of low incidence in hemodialysis patients, and is mostly unsuccessful. However, the modern advances in hemodialysis therapy, the wide choice of anti-hypertensive, the correction of anemia, and the improvement in the general health of HD patients may improve the outcome.
Keywords: Hemodialysis, Pregnancy, Chronic renal failure.
|How to cite this article:|
Sulaiman I. Pregnancy in Hemodialysis Patients. Saudi J Kidney Dis Transpl 1997;8:32-5
| Introduction|| |
Though pregnancy is a physiological phenomenon, it has a serious impact on the management of women on dialysis due to volume expansion and the worsening of anemia and hypertension during pregnancy ,, . Morbidity and mortality in both mother and fetus are considerable  . Moreover, medications for hypertension, method of hemodialysis need several modifications in order not to compromise maternal and fetal physiology. We aimed in our study to evaluate the various therapeutic modifications during pregnancy in women on dialysis, and to compare our results with, reports from the literature.
| Subjects and Methods|| |
We reviewed the cases of pregnancy in our hemodialysis unit at King Fahd Hofuf Hospital (KFHH) - Saudi Arabia over a period of six years (1988-1994). Our study included the incidence of pregnancy in women on hemodialysis during their child bearing age, its relation to the age of patients, the period of hemodialysis before pregnancy occurred, number of pregnancies before hemodialysis was initiated, the menstrual history, the complications including vaginal bleeding, hydramnios and spontaneous abortion, and the final outcome of these pregnancies. Blood pressure control, average serum creatinine, Blood Urea Nitrogen (BUN), Hemoglobin. Calcium, and number of blood transfusion during pregnancy were followed up closely. We also studied the therapeutic and prophylactic interventions in these pregnant patients. These measures were followed:
1. Keeping the blood pressure around 140/90 mmHg by appropriate restriction of fluid and salt intake, control of ultrafiltration during dialysis besides medications if necessary.
2. Maintaining the hemoglobin levels at 80 g/L or higher by using blood transfusions if needed. None of our patients received erythropoietin.
3. Maintaining BUN below 25nimol/L by increasing the duration and frequency of hemodialysis.
4. Using regional heparinization during dialysis to minimize the risk of bleeding.
5. Using bicarbonate dialysate instead of acetate dialysate in dilalyzing these patients.
| Results|| |
There were 80 women on dialysis, with ages ranging between 15 and 45 years, available for evaluation at our center during the study period. [Table - 1] shows the demographic data of these patients. There were six pregnancies (7.5%) in five of these patients, at the time of diagnosis of pregnancy; all the pregnant patients had histories of scanty irregular menstrual cycles. Four of them had no periods for more than two months, while the remaining patient had vaginal bleeding. Urine pregnancy test was positive, and sonogram confirmed the diagnosis of pregnancy in all of these patients.
The number of pregnancies in our patients before initiation of hemodialysis (HD) ranged from 0 to 10 pregnancies. The duration of HD before the occurrence of pregnancy ranged from 1 to 4 years. Out of all the pregnancies in our study, there was a satisfactory control of pre dialysis BUN in four of them (three of them had BUN less than 70mmol/L). Two other patients had always higher BUN (more than 27mmol/L) and both ended with spontaneous abortion.
The control of blood pressure to 140/90 mmHg or less was achieved in three patients only by volume control, while other two patients needed the addition of anti-hypertensive drugs, but one of them had particularly difficult blood pressure to control despite intensive therapy. None of the study group had any episodes of hypotension during dialysis.
Four patients had hemoglobin level above 80 g/L, while the level ranged between 70-80 g/L in the other two. Though all patients had regional heparinization during dialysis, only one patient had many episodes of vaginal bleeding. However, these episodes were controlled without sequellae.
Four pregnancies ended with normal spontaneous delivery, of whom three were premature and one reached full term. The other two pregnancies ended with spontaneous abortion.
All the living infants at the time of delivery-were small-to-date. Two of them died during the neonatal period while the other two remained alive and healthy. One of them is now five years old and the other is 1 ˝ years old at the time of this report.
| Discussion|| |
More than half of the female hemodialysis patients in the reproductive period are usually amenorrhic, while the rest of them have irregular anovulatory cycles and infertility  . There is absence of midmenstrual cycle surge of gonadotropines besides hyper-prolactinemia , .
The diagnosis of pregnancy is difficult in hemodialysis patients and needs a high degree of suspicion, since gastric symptoms due to uremia may mimick early symptoms of pregnancy. Moreover, the urinary pregnancy test (if there is any urine) could be falsely positive due to the raised level of Human Chronic Gonadotropin (HCG) in renal failure patients without pregnancy.
In chronic renal failure (CRF) patients, many pregnancies end with spontaneous abortion and misdiagnosis  . In many studies, pregnancies have been reported just before or soon after starting HD while there is some residual renal function  . The duration of HD before the occurrence of pregnancy in our patients was variable, and some of them had previous pregnancies before acquiring the renal disease.
Fetuses in CRF patients are prone to growth retardation, pre-maturity, vertical transmission of viral infection and fetal death  . Pregnant women on hemodialysis are susceptible to fluid overload, severe hypertension, severe anemia, vaginal bleeding and spontaneous abortion  . In our study, there were only six pregnancies in 5 patients. Though the number was small, because of the rarity of the condition, we thought it could still elicit significance and interest. The estimated prevalence of pregnancy in our study was 7.5%. This is higher than what had been observed in many other studies  .
In our study, two patients had persistently elevated pre-dialysis BUN (more than 27mmol/L) and both ended in spontaneous abortion. However, pre-dialysis BUN was always less than 18mmol/L in two patients and between 18 and 27 mmol/L in two patients. Though nothing has been reported clearly , , we believe it is safer to have pre-dialysis BUN of less than 25mmol/L in pregnant patients on dialysis.
During hemodialysis, use of regional heparinization minimizes incidents of bleeding  . Inspite of this, one of our patient had many episodes of spontaneous vaginal bleeding, fortunately without any sequellae. Clotting of vascular access is a known complication during pregnancy  . However, this was fortunately not seen in any of our patients.
We believe that bicarbonate containing dialysate with enough glucose concentration may be preferable in pregnant women on hemodialysis in order to prevent symptoms related to acetate containing dialysate.
Hypertension in CRF is usually aggravated in pregnancy , . First line management in pregnant CRF patient should be fluid restriction, followed, if not controlled, by adding drugs like Methyldopa, Hydralazine, Beta blocker, or Calcium channel blocker. The Usage of Angiotensin Converting Enzyme inhibitors is likely to increase the risk of fetal death and acute renal failure in the new born, hence it is contraindicated in pregnancy  .
Anemia is also aggravated during pregnancy in CRF patients. Blood transfusion and erythropoietin were reported to be useful to overcome this problem , . Due to the possible risk that erythropoietin could increase the blood pressure and cause clotting of vascular access we refrained from using it in our study patients. However, there have been reports of successful pregnancies with erythropoietin , .
Theoretically, Continuous Ambulatory Peritoneal Dialysis (CAPD) in pregnant CRF patients minimizes wide fluctuation in BP and intravascular volume, and avoids heparinization. However, CAPD is not without complications as peritoneal catheter malfunction, peritonitis, ectopic pregnancies due to adhesion and easy fatigue due to fluid and fetal volume. Pregnancy in CAPD patients, which we have no experience of, has been reported to be successful ,, .
We believe that nutrition should be strictly followed up in pregnant CRF patients. The daily protein intake should be 1.5 g to 2 g/kg of body weight. Potassium allowance should be close to 50 mmol daily, and the sodium should be around 80 mmol daily with enough supplements of vitamins B,C, folic Acid and vitamin D. In case of uncontrolled BP or pre eclampsia or if intra uterine fetal death is anticipated, elective termination of pregnancy should be planned for.
We conclude from our study that pregnancy is rare in hemodialysis patients, and is mostly unsuccessful. However, the modern advances in hemodialysis therapy, the wide choice of anti-hypertensive, the correction of anemia, and the improvement in the general health of HD patients may improve the prognosis.
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Consultant Nephrologist, Hemodialysis Unit, Al Asad University Hospital, Lattakia, Syria
[Table - 1]