Pregnancy outcomes in kidney transplant recipients

1. Pregnancy outcomes in kidney transplant recipients M. Wyld, P. Clayton, S. Jesudason, S. Chadban, S. Alexander

2. What pregnancy outcomes should women with kidney transplants expect? • Transplantation improves fertility for ESKD patients • Maternal outcomes have been well documented • Evidence suggests that pregnancy does not adversely impact graft function or maternal survival - ANZDATA cohort study, Levidiotis et al (2010) • Outcomes of the babies born to transplant mothers have been less well described

3. Aims • Examine pregnancy outcomes for women with kidney transplants. • Compare these outcomes to those in the general Australian population.

4. Data sources Transplant patients: ANZDATA • Female transplant recipients in whom a pregnancy was reported between 1971 and 2010 • Gestational age and birth weight were collected from 2001 General population: National Perinatal and Epidemiology Statistics Unit’s (NPESU) annual ‘Mothers and Babies’ reports • Reports on all births in Australia • Annual data available from 1991-2010

5. Maternal characteristics

6. Maternal characteristics: Type of kidney disease and transplant source

7. Live birth of ~88% for the last three decades Pregnancy outcomes in transplant recipients by decade, 1971-2010 *Excluding terminations

8. Terminations have fallen dramatically Percentage of pregnancies terminated by decade

9. Babies born to transplant recipients are born earlier Gestational age group at birth, 2001-2010 • Transplant population • Mean gest age of 35 (±5) weeks • 54% preterm • General population • Mean gest age of 39 weeks • 7% born preterm • Difference • Statistically significant (p<0.001)

10. Babies born to transplant recipients are born earlier Gestational age group at birth, 2001-2010 • Transplant population • Mean gest age of 35 (±5) weeks • 54% preterm • General population • Mean gest age of 39 weeks • 7% born preterm • Difference • Statistically significant (p<0.001)

11. Multivariable analysis: predictors of gestational age

12. Multivariable analysis: predictors of gestational age • Only time since transplantation was a significant predictor of gestation (P=0.04) • Each additional year from transplant added 0.13 weeks (~1 day) to expected gestation

13. Transplant babies were smaller Birth weight by gestational age for live singleton babies born to transplant recipients compared to national Australian percentiles • Transplant population • Mean birth weight of 2485 (±783) g • 46% low birth weight (<2500g) • 8% very low birth weight (<1500g) • General population • Mean birth weight of 3358g • 7% low birth weight • 2% very low birth weight • Multivariable analysis • Only gestational age a significant predictor • Birth weight 136g per 1 week gestation

14. Transplant babies were more likely to be small for gestational age Percentage of births small for gestational age (≤10th percentile) and ≤ 3rd percentile P<0.0001 P<0.0001

15. Still birth rate for transplant recipients falling Percentage of pregnancies longer than 20 weeks gestation that ended in stillbirth for transplant population

16. …but remains significantly higher than in the general population Percentage of pregnancies longer than 20 weeks gestation that ended in stillbirth for transplant population compared to general population P<0.001

17. Increased maternal age associated with live birth rate Variables associated with a live birth* *Excludes terminations

18. Increased maternal age associated with live birth rate Variables associated with a live birth* *Excludes terminations

19. Neonatal mortality is high in transplant population- but accounted for by prematurity Neonatal mortality of births after 20 weeks of gestation or more, 2001-2010 • Difference is very large • Without adjusting for gestational age, difference is significant (p<0.001) • When gestational age is adjusted for difference is not significant (p=0.1)

20. Second pregnancies often had longer gestations • Mean GA for 1st pregnancy = 35.8 (±3.4) weeks • Mean GA for 2nd pregnancy = 37.7 (±3.6) weeks • Difference statistically significant (p=0.04)

21. Paediatric at transplant:outcomesinbrief

22. Maternal characteristics – Paediatric transplant recipients

23. Live birth rates higher in paediatric transplant patients (mainly due to fewer spontaneous abortions) Pregnancy outcomes in transplant recipients by decade, 1971-2010 *Excluding terminations

24. Termination rates have been higher until the last decade Percentage of pregnancies terminated by decade

25. Babies born to paediatric transplant recipients have a slightly lower chance of being preterm Gestational age group at birth, 2001-2010 • Paediatric population • Mean gest age of 36 (±5) weeks • 39% born preterm • Adult population • Mean gest age of 36 (±4) weeks • 56% preterm • No significant diff in mean GA (p=0.4)

26. Paediatric transplant babies were more likely to be small for gestational age Percentage of births small for gestational age (≤10th percentile) and ≤ 3rd percentile P<0.0001 P<0.0001

27. Summary • Pregnancies in transplant recipients are high risk • High rates of preterm birth • Lower birth weights • Higher rates of perinatal death • Women who have a second pregnancy tend to have longer gestational periods • Patients who were paediatric at transplant were less likely to deliver early, but more likely to have SGA infant • However, overall outcomes are very good with a high live birth rate and declining perinatal mortality

28. Twins born to transplant recipients are usually born ‘very pre-term’ Twin births - gestational age group at birth, transplant population compared to general population (2001-2010)

29. Maternal characteristics: Immunosuppression by era(1970-2010) Changes over time in the five most common maternal immunosuppression regimens