It appears there is a battle being waged in the mother-to-be’s uterus. The biological goal of having the largest healthiest baby and the mother’s goal of living through the delivery. It could be that preeclampsia is the uterus’s response to a baby that is too large and a move toward maternal self-preservation, according to researchers from Yale. Their report is published in the October issue of Reproductive Sciences.
The baby’s placenta does battle on behalf of baby size. The cells of the placenta are called trophoblasts. Researchers have observed ways that the placenta tricks the mother in order to get increased blood flow and grow the baby. The placenta’s whole job is secure nutrients from the mother. Special invasive trophoblasts leave the placenta and attack the mother’s tissues destroying the walls of her blood vessels. This increases blood flow to the placenta, feeds the baby and increases its size. Usually the mother’s lymphocytes fight back by destroying the trophoblasts. The placenta, aware of the lymphocytes counter attacks, will actually creating diversion for the lymphocytes so that the invasive trophoblasts can have successful secret attacks on other parts of the uterus. The diversion is brilliant: the placenta secretes a placental protein (PP13) into the mother’s blood where it travels through her veins into the uterus below the placenta. There PP13 leaves the veins where it triggers the mother’s immune system to react and attack. The area around these veins becomes an inflamed mass of dead cells called necrosis.
If the deception doesn’t work and the blood flow is limited, preeclampsia may develop. Preeclampsia is a condition that results in high blood pressure and protein in the mother’s urine. There is no cure and usually the baby must be delivered early or is lost in miscarriage.
“We realized that these zones of necrosis are likely occupying the mother’s soldiers while the invasive trophoblasts sneak into her arteries, leading to more blood flow to the placenta and a bigger baby,” said Harvey Kilman, MD, research scientist in the Department of Obstetrics, Gynecology and Reproduction at Yale School of Medicine. “We believe that maintaining this balance could be the key to a healthy pregnancy free from preeclampsia.”
Source: Reproductive Sciences, MedicalNewsToday
