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

Abstract

Aims: 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.

Methods: 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.

Results: 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.

Conclusion: 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).