Selective Intrauterine Growth Restriction (sIGUR)


In this condition, commonly seen in twins with a common placenta (monochorionic), there is disproportionate sharing of the placenta. Consequently, one twin is at risk for under-nourishment and poor growth. In the most severe cases, the risk of death to the twin can be as high as 40 percent.


The condition is usually diagnosed by routine ultrasound evaluation when one twin is markedly smaller than the other (estimated weight is less than 10 percentile). Your doctors will evaluate the severity of the condition by assessing blood flow through various blood vessels in both fetuses using Doppler ultrasound. Other tests such fetal echocardiography may be needed.


Aside from expectant management, another intervention includes selective termination of the smaller twin in severe cases for the protection of the co-existing twin from risk of death or neurologic damage in case the smaller one passes away.

Although there are trials examining the utility of laser photocoagulation for cases of selective IUGR, presently, this intervention is reserved for clinical scenarios with accompanying TTTS or impending fetal death of the smaller twin.