Background Twins have a higher mortality and morbidity than singletons and,
among twins, the surviving co-twin of a fetus that dies in utero is partic
ularly at risk. We did a cohort study to quantify mortality and serious mor
bidity in co-twin survivors of fetuses that died in utero.
Methods We collected data of all registered twin births in England and Wale
s between 1993 and 1995 in which one twin was registered as having died in
utero. Copies of all death certificates of these fetuses and death certific
ates of live-born co-twins of fetuses that died in utero were obtained from
the Office for National Statistics. A questionnaire was sent to the genera
l practitioners of all surviving co-twins to find out if the child had any
disability.
Findings There were 434 fetal death/live-birth same-sex twin pairs. Among t
he live births, there were 59 neonatal deaths, seven postneonatal deaths (f
irst 28 days), and five infant deaths (<1 year). In three of the five death
s, the cause of death was cerebral palsy. Ten of the children who survived
infancy were lost. to follow up. Responses were received from general pract
itioners for 241 of 353 survivors (68% response). Of the 241 respondents, 2
3 had cerebral palsy and 28 had other cerebral impairment. Among the childr
en who survived to infancy, the prevalence of cerebral palsy was 106 (95% C
I 70-150) per 1000 and prevalence of other cerebral impairment was 114 (80-
160) per 1000. There were 163 fetal death/live-birth different-sex twin pai
rs. Of the live births, 13 died in the neonatal period and four were lost t
o follow up. Of the 146 survivors, responses were received from the general
practitioners for 102 (70% response). Three of the 102 had cerebral palsy
and 12 had other cerebral impairment. The prevalence of cerebral palsy was
29 (95% CI 6-83) per 1000 and of other cerebral impairment 118 (62-196) per
1000 infant survivors.
Interpretation The live-birth cc-twin of a fetus that died in utero is at i
ncreased risk of cerebral impairment, the overall risk is 20% (95% CI 16-25
). The gestational-age-specific prevalence of cerebral palsy after fetal de
ath of the co-twin is much higher than that reported for the general twin p
opulation.