Successful twin pregnancy in a patient on long-term haemodialysis

Chiz-Tzuang Chang, Mai-Szu Wu and Hong-Chiz Chien

Division of Nephrology, Chang Gung Memorial Hospital, Taipei, Taiwan

Correspondence and offprint requests to: Mai-Szu Wu, Division of Nephrology, Chang Gung Memorial Hospital, 199, Tun Hwa North Road, Taipei, Taiwan.

Keywords: twin pregnancy; chronic haemodialysis



   Introduction
 Top
 Introduction
 Case
 Discussion
 References
 
Pregnancies in end-stage renal disease (ESRD) are uncommon, and a successful outcome is rare [1]. Pregnancy in uraemic patients puts the mother at risk of hypertension and fluid overload [2]. On the other hand, there is an increased risk for the fetus of neonatal mortality, prematurity, and small-for-gestational-age [3]. Twin pregnancies are regarded as high-risk pregnancies even in healthy women and must be even more risky in dialysed women. We report on a 30-year-old female on chronic haemodialysis for 7 years who conceived after induced ovulation and had a twin pregnancy.



   Case
 Top
 Introduction
 Case
 Discussion
 References
 
A 30-year-old female, without a previous pregnancy suffered from chronic glomerulonephritis since childhood. She had started maintenance haemodialysis (thrice weekly) 7 years ago. She was a hepatitis virus B and hepatitis virus C carrier. For this reason, she was not considered for kidney transplantation. She married a renal transplant recipient 4 years after initiation of haemodialysis. She could not conceive after 3 years of unprotected intercourse. As she was eager to have a child of her own, she underwent hormone-stimulated ovulation with timed intercourse. She conceived and had a twin pregnancy within 3 months of hormone therapy, including clomiphen and human chorionic gonadotrophin (HCG). Pregnancy was diagnosed from the elevation of HCG at the 3rd week of pregnancy.

The dosage of haemodialysis was increased to six times per week and 4.5 h/session. The weekly dialysis time was extended to 27 h from the 3rd week of pregnancy. The dialysate was changed to high calcium concentration (3.5 mmol/l) dialysate containing glucose (200 mg/dl) to meet the increased calcium need of the mother and prevent hypoglycaemia during haemodialysis [4]. The dose of erythropoietin (Epo) was increased from 4000 U to 12 000 U weekly to counteract the Epo hyporesponsiveness during pregnancy [5]. Folic acid supplement was increased from 5 to 35 mg per week to avoid folate deficiency [6]. An oral (100 mg elemental iron/day) and intravenous iron supplement (40 mg elemental iron/week) were given to keep serum ferritin above 500 ng/ml. The haematocrit was maintained between 29 and 33%. The patient had regular obstetric follow-up with fetal sonography every 3 weeks after the 21st week of pregnancy.

The course of the patient's pregnancy was smooth except for an episode of vaginal spotting at the 29th week. The bleeding ceased under conservative therapy. Preterm labour pain developed at the 32nd week of gestation. Tocolysis failed to relieve the persistent uterine contraction. She underwent Caesarean section and delivered a pair of male twins. The first baby weighed 1292 g with an Apgar score of 9 at 5th minute. The second twin was delivered 1 min later, weighing 958 g, and with the same Apgar score. The mother had persistent post-partum haemorrhage caused by a retained placenta. She underwent hysterectomy and was discharged 1 week later. The two babies were transferred to the neonatal ICU because of their prematurity. They were discharged uneventfully after their body weight had risen to 2000 g 2 months later.



   Discussion
 Top
 Introduction
 Case
 Discussion
 References
 
Fertility is markedly decreased in women on chronic haemodialysis [1]. Souqiyyeh et al. reported a rate of conception of 1.2% among female chronic dialysis patients of childbearing age in Saudi Arabia [7], where contraception is restricted by religious tenet. The National Registry for Pregnancy in Dialysis Patients (NPDR) reported that over a 4-year period 2.4% of 4531 female haemodialysis patients of childbearing age became pregnant in the United States [1]. Successful pregnancies are seen in only a small fraction of pregnancies of haemodialysis patients, e.g. 25% in Europe [8] before the introduction of erythropoietin. The success rate increased to 39.5% recently [1]. Transplantation restores fertility [9] and improves the likelihood of a successful pregnancy [10]. It offers the best chance of a child for women with end-stage renal disease.

Previous studies had indicated that adequate dialysis, haemodynamic stability, anaemia and nutrition are the most important factors for a successful pregnancy in chronic haemodialysis patients. The report of the registry of pregnancy in dialysis patients suggested that there was a trend toward better pregnancy outcome and reduced fetal prematurity in patients with weekly dialysis exceeding 20 h. There was also a positive correlation between birth weight and dialysis time [11].

After gestation had been diagnosed promptly, we increased our patient's usual weekly 12-h haemodialysis to 27 h from the 3rd week of gestation. We used high-flux dialysers (FB210U, urea clearance 198 ml/min, NiproTM, Japan) to keep her pre-dialysis urea concentration lower than 60 mg/dl as suggested by Maruyama et al. [5] to reduce the incidence of polyhydramnion [12]. Reducing interdialytic body-weight gain by daily intensive haemodialysis prevented haemodialysis-related hypotension, which is detrimental for the fetus [10]. Hypertension is common among pregnant haemodialysis patients [11]. Hypertension or hypotension were avoided throughout the entire pregnancy in our patient. Her monthly blood sugar check-up was normal and iPTH levels were kept between 130 and 180 ng/ml during the pregnancy, even with high-calcium dialysate containing glucose.

Correction of anaemia possibly increases the success rate of pregnancy and prevents hypoxaemic stress in the fetus, but increased doses of Epo should be given to counteract the Epo hyporesponsiveness of pregnancy [5]. Epo does not pass through the human placenta [13]. No Epo-related teratogenicity has been reported [6]. Our observation indicates that Epo is an effective and safe therapy for the pregnant haemodialysis patient.

An adequate dietary prescription is mandatory for maternal health and fetal development. With intensive haemodialysis, dietary restrictions could be liberalized without running the risk of azotaemia and hyperkalaemia. In our patient, the serum albumin level was kept between 3.5 and 4.2 g/dl, although there is a physiological decrease in serum albumin concentration in normal pregnancy.

Our observation illustrates that intensified dialysis regimens and attentive medical care permit a successful outcome even in high-risk twin pregnancies of dialysed women.



   References
 Top
 Introduction
 Case
 Discussion
 References
 

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Received for publication: 28. 4.99
Accepted in revised form: 7. 6.99