The blood connection: fetus in the womb


By Hiya Islam

ScienceThe consequences of incompatible blood-mixing can prove to be fatal during transfusions. All the same, the same instance can also occur in womb where the baby is held so closely to the mother by the umbilical cord attached to the placenta. By understanding the chemistry of antigens from last week, let’s have a look at how these chemicals can work to put the bond between mother and baby at risk.

The placenta is an organ that forms in the uterus or womb during pregnancy. It is responsible for the transport of oxygen, glucose and other nutrients to the growing fetus and the removal of metabolic wastes like, carbon dioxide from its blood. Complications arise when a Rh-negative mother is carrying a Rh-positive baby. Blood can mix, even in tiny amounts, during delivery or invasive prenatal testing procedures, due to strong blows to the abdomen. Manual rotation of breech baby can also be a cause. Breech babies are called so because they are positioned to come out feet or bottom first instead of head first. This poses significant risk to the baby during birth. However, it is important to note that mothers and babies never share their blood systems. Detecting the blood cells of the fetus in the bloodstream, the mother produces an immune response that is antibody secretion. Antibodies made in mother’s body reach the fetus via placenta and start to attack its red blood cells. This results in a medical condition known as hemolytic anemia or in highly scientific terms ‘erythroblastosis fetalis’. Red blood cells (RBCs) are the ones carrying oxygen to each part of the body and leaving the condition un-treated can be life-threatening for the baby. The fetus will try to cope up with the situation by making more RBCs in the bone marrow. As a result, liver and spleen enlarge which is one of the symptoms of the disease. Overproduction of RBCs puts everything in chaos. Even formation processes of other cells are disrupted. With so many RBCs flowing around, there is an inefficiency in breaking these down. Bilirubin, a by-product of RBC breakdown, accumulates leading to jaundice.

Prevention is better than cure. With the rise of modern technologies and new discoveries, expecting mothers are now injected with anti-D immunoglobin. It prevents formation of antibodies in the first place. The time of administration is specific. It can be during pregnancy and after delivery as well. Routine blood samples from the mother allow antibody levels to be monitored. In cases where antibodies are already present, blood transfusions are provided to the baby before birth. And sometimes, an early delivery via induction or C-section is done. After birth, the baby is placed in neonatal care and given additional transfusions, if required. Special therapy using light, photo therapy is given to treat the jaundice.


HIya Islam is a student of BRAC University.


Comments are closed.