B. Equal in incidence in all races.
C. An indicator of considerably increased incidence of major malformation of the fetus.
D. Equally common in newborns of diabetic and nondiabetic mothers.
The structure marked in the picture above represents Umbilical cord.
The absence of one umbilical artery occurs in 0.7 to 0.8% of all umbilical cords of singletons, in 2.5% of all abortuses, and in approximately 5% of at least one twin. The incidence of a single artery is significantly increased in newborns of diabetic mothers, and it occurs in white infants twice as often as in newborns of black women.
The incidence of major fetal malformations when only one artery is identified has been reported to be as high as 18%, and there is an increased incidence of overall fetal mortality. The finding is an indication to offer amniocentesis, cordocentesis, or chorionic villus sampling to study fetal chromosomes, although there is debate about whether this should be done when there is only a truly isolated finding of single umbilical artery.