Sudden infant death syndrome and complications in other pregnancies.
BACKGROUND
The likelihood of recurrence of sudden infant death syndrome (SIDS) is an issue of biological, clinical, and legal interest. Obstetric complications are associated with an increased risk of SIDS and are likely to recur in subsequent pregnancies. We postulated that women whose infants died from SIDS would be more likely to have had obstetric complications in their other pregnancies.


METHODS
We linked national UK databases of maternity-hospital discharges, perinatal deaths, and death certifications. We studied 258 096 women who had consecutive births in Scotland between 1985 and 2001.


RESULTS
Women who had an infant who died from SIDS were at increased risk in their next pregnancy of delivering an infant small for gestational age (odds ratio 2.27, 95% CI 1.54-3.34, p<0.0001) and of preterm birth (2.53, 1.82-3.53, p<0.0001). The risk of SIDS was higher for the children of women whose previous infant had been small for gestational age (1.87, 1.19-2.94, p=0.007) or preterm (1.93, 1.24-3.00, p=0.004). Multivariate analysis showed that all associations were explained by common maternal risk factors for SIDS and obstetric complications and by the likelihood of recurrence of fetal growth restriction and preterm birth.


CONCLUSIONS
Women whose infants die from SIDS are more likely to have complications in their other pregnancies. Recurrence of pregnancy complications predisposing to SIDS could partly explain why some women have recurrent SIDS.
Smith
Gordon C S
GC
Department of Obstetrics and Gynaecology, Cambridge University, Rosie Hospital, Cambridge CB2 2SW, UK. gcss2@cam.ac.uk
Wood
Angela M
AM
Pell
Jill P
JP
Dobbie
Richard
R
D001724:Birth Weight; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D008498:Medical Record Linkage; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D012008:Recurrence; D012042:Registries; D012307:Risk Factors; D012606:Scotland / Q000453:epidemiology; D013398:Sudden Infant Death / Q000453:epidemiology*