An observational outcomes study from 1966–2008, examining pregnancy and neonatal outcomes from dialysed women using data from the ANZDATA Registry

Abstract

To conduct an observational outcomes study examining pregnancy and neonatal outcomes of dialysed women aged 15-49, from 1966-2008, using data from the ANZDATA Registry. Data from the ANZDATA Registry were captured and analysed from 1966-2008. Specific pregnancy outcomes included: live birth (LB), spontaneous abortion, stillbirth (SB) or termination of pregnancy. Delivery and neonatal outcomes, since 2001, were also analysed. There were 23 700 person-years (PY) of observational data during the study period with 49 pregnancies, of which 30 (79%) resulted in a LB, once terminations were excluded. Pregnancy rates: Overall the pregnancy rate was 2.07 per 1000 PY for the study interval. A significant increase in the pregnancy rate was noted for the 1996-2008 time interval (3.3 per 1000 PY, compared with 0.54 and 0.67 in the eras 1976-1985 and 1986-1995, respectively; P = 0.004). Most pregnancies were observed in the 25-29 age group: 20-24, 25-29 and 30-34 (5.31, 5.61 and 3.87 per 1000 PY, respectively). Patients on peritoneal dialysis were less likely to achieve a pregnancy compared with haemodialysis patients (P < 0.02). Live birth rates: The overall LB rate was 1.26 per 1000 PY. The rate for each of the age brackets was as follows: 3.54 for 20-24, 3.61 for 25-29, and 2.39 per 1000 PY for 30-34, compared with 0 in the 15-19 group, and 1.22, 0.2 and 0.16 per 1000 PY among the groups 35-39, 40-44 and 45-49 years, respectively. LB rates were more favourable in the younger age groups. There was no significant era, disease, dialysis modality or race effect on LB rates. Excluding terminations, the LB rate was 79%. Age-effect on pregnancy outcomes: Pregnancy outcome was not affected by age (mean ages shown): spontaneous abortions, 28.7 years (n = 3); LB, 29.3 years (n = 24); SB, 32.4 years (n = 5); terminations 30.6 years (n = 11). Maternal mortality and complications: The preeclampsia rate was 19.4% (6/31). No post-partum maternal deaths were reported. Neonatal outcomes: Since 2001, 21 neonatal outcomes were reported. One baby developed polyhydramnios, one had a congenital malformation and one post-natal death was reported. In total 53.4% were born preterm; 65% had a birthweight <2.5 kg (low birthweight) and 35% <1.5 kg (very low birthweight). Low birthweight correlated with prematurity. Seventy-nine per cent of women achieving a pregnancy in our cohort achieved a LB, although 53.4% of babies were born preterm and 65% were of low birthweight (<2.5 kg).