When One of the Twins Die In Utero
Did you always think that when a mother conceives twins, triplets, quadruplets or more, all of the fetus will be born alive? As morbid as it maybe, some fetus/fetuses die prematurely even before being born. Some may die within the first, 2nd or 3rd trimester (3 months). And their death can bring about complication/s not only to the mother, but to the remaining twin as well.
The effect of the fetal death to the surviving twin may vary according to the timing of the death. In a data published 1994, loss of one twin at the first trimester does not impair the development of the surviving fetus. (Some are completely resorbed in a condition termed as “vanishing twin syndrome.”) In the second trimester however, this is associated with increased risk for the survivor as reflected by a high incidence of growth retardation, premature labor and perinatal mortality.
An observation of twin pregnancies where single fetal death occurred after 20 weeks of gestation, the mothers were known to have preeclampsia which may also prompt babies to be delivered prematurely. The surviving twin aside from being delivered prematurely, they are also observed to be with intrauterine growth restriction. This could be an effect of the death of the other twin, or that and the effect of preeclampsia wherein the blood flow to the fetus may become diminished. This in turn causes diminished delivery of oxygen and nutrients to the baby thus. Head MRI and ultrasound of these survivors revealed some neurologic injury. Fortunately, in these mothers, there was no detected abnormality on coagulation profile.
A similar observational study was also done among twin pregnancies where a single fetal death occurred after 20 weeks of gestation. The study showed that the main cause of the fetal death was twin-to-twin transfusion syndrome. The survivors were also delivered prematurely and later also died after birth because of the same cause. (TTTS is due to abnormal communication between the blood vessels supplying the placenta of both, leading to shunting of more blood to the other twin while deprivation of the other one. One may die immediately while still in utero, while the other may survive or end up hydropic; or both may survive with severe physical discrepancy — see my other blogs on hydrops fetalis).
Another in depth observation was done among twin pregnancies complicated by single intrauterine fetal death after 26 weeks of gestation. Chorionicity of the twin pregnancies was noted (see illustration below on the types of twin pregnancy according to chorionicity).
(Image courtesy of http://www.health.sa.gov.au/ppg/Default.aspx?PageContentMode=1&tabid=75)
Often times, the surviving twin was delivered prematurely, and that baby ended up with intrauterine growth restriction. The mother on the other hand had preeclampsia and gestational diabetes, both of which may also lead to the growth restriction of the surviving twin. In cases of monochorionic pregnancies, again twin-to-twin transfusion syndrome afflicted the babies. Some of the twin eventually died as well in utero (before being delivered), while others after birth. Also, ultrasound of the baby’s head should cerebral anomalies in some.
Even if one of the twins survive after the death of the other, and gets delivered, it is not reassuring that he will live and be discharged as well baby as his outcome may be compromised by the complications of premature birth, or presence of neurologic injury.