Main findings
The commonest associated aetiology with sIUFD in MC twin pregnancies was
TTTS and the majority had undergone prenatal therapy prior to sIUFD (as
opposed to being conservatively managed). The second most common
aetiology was “spontaneous” with no obvious underlying aetiology (i.e.
no signs of TTTS, sIUGR or congenital/structural anomaly), followed by
congenital/structural anomaly, and sIUGR being the least common. Death
of the co-twin following sIUFD was common, complicating 1 in 7
pregnancies. Less than two thirds of cases had investigation by
antenatal CNS imaging to identify ischaemic brain injury. Of the cases
whose imaging results were known to the UKOSS reporter, 1 in 5 had
radiological findings suggestive of neurological morbidity. Postnatal
CNS imaging revealed a further 7 babies with brain abnormalities (mainly
on cranial USS), all of which were born at <36 weeks, and 4 of
whom also had abnormal CNS signs. Preterm birth was the commonest
adverse outcome, with three quarters of twins born at less than 37 weeks
gestation, and an equal split between spontaneous preterm birth, and
those delivered iatrogenically. Major maternal morbidity was not
uncommon, with 6% requiring ITU admission, compared to 0.22% of the
general obstetric population reported in the 2015/2016 National
Maternity and Perinatal Audit18. Interestingly, all
maternal admissions were related to sepsis, although not all women had
undergone prenatal ‘invasive’ interventions for therapy.