Vanishing Twin: A Possible Cause of Cerebral Impairment

Abstract

Fetal death in a twin conception during second and third trimester is associated with increased risk of cerebral injury in the surviving twin. The aim of this study is to test the hypothesis that even early fetal losses as a ‘vanishing’ twin may be associated with an increased risk of cerebral impairment in the surviving twin. The study population comprised 362 pregnant women attending Liverpool Women's Hospital recruited between 1999 and 2001. Women were classified according to the first ultrasound scan into 3 groups: vanishing twin, twin and singleton. The vanishing twin group was further subdivided into ‘definite’ and ‘probable’. Children from these pregnancies were assessed at 1 year of age for their development and neurological function using the Griffiths Mental and Developmental Scales and Optimality score. Children from 229 pregnancies (63.2%) attended the assessment. Information on children from a further 21 (5.8%) pregnancies was obtained through a review of hospital records. Cerebral impairment was found in 2 children from the vanishing twin group, 2 from the twin group and none from the singleton group. When cases with definite vanishing twin are considered there is a significant difference between the vanishing twin and singleton group (relative risk 6.1; 95% confidence interval 1.5–8.3; p = .03). An additional study with an increased sample size would enable a more robust conclusion.

Prematurity and twinning

“…Given that about 1/8 of all natural pregnancies are initially multiple with subsequent spontaneous early loss of one or more foetuses (vanishing twin phenomenon), it has been suggested that a significant proportion of singletons with spastic CP may be the result of the death of a co-twin in the second half of gestation [18]. In monochorionic twin pregnancies, the death of one twin late in gestation is recognized as being an important risk factor for the surviving co-twin to have CP.…”

Multiple Pregnancies

“…If the reported cases are applicable to the general population, the excessively high frequency of calculated twin gestations is surprising. Two searching papers by Anand et al ( 2007 ) attempted to ascertain whether vanished twins had any signi fi cant effect upon the cerebral capacity of the survivor. No unequivocal results were obtained.…”

Survivor of Co-Twin Following Intrauterine Demise of One Fetus

“…[11] Different anastomotic channel are seen -artery to artery, artery to vein, vein to vein. Complication that occurs are twin to twin transfusion syndrome, discordant twin, cerebral palsy, porencephaly microcephaly, multicystic leukomalacia [12][13]. Neurological damage is most likely caused by ischemic necrosis leading to cavitary brain lesions.…”