Placental infarction or a piece of the placenta that has died is a common finding in term pregnancies. It’s a condition which occurs in about a quarter of all normal pregnancies.
This condition, however, can be injurious to the fetus if the placental infarction is large or if there are multiple placental infarctions to the point where the oxygen and nutrients to the fetus are interrupted. Patients with hypertension are more likely to have placental infarcts compared to normotensive patients. The fetus affected by the placental infarcts in the hypertensive patient has a poorer outcome compared to the fetus from the patient not afflicted with hypertension. The head circumference of the fetus in the compromised hypertensive patient is smaller than the head circumference of the normotensive patients.
There are cases, however, where the placental infarcts occur in normotensive patients. Infarctions can be associated with preterm labor. The exact mechanism by which placental infarctions start preterm labor is unknown. It is believed that infarcts found in the center of the placenta are more significant for fetal compromise than those found on the edge of the placenta.
It is recommended that all placentas associated with preterm labor and deliveries be examined histologically for abnormalities like infarction.
There is a condition known as placental hematoma infarction where fetal death and adverse outcomes are common. In this condition, there are blood clots (hematomas) present in the body of the placenta surrounded by infarcted placental tissue. This condition has been associated with preeclampsia and intrauterine growth retardation.
Ultrasound can sometimes make the diagnosis of placental hematoma infarction although the diagnosis of infarction is difficult on ultrasound. The ultrasound picture will show cystic areas in the placenta when the diagnosis is made.
If a diagnosis of placental infarct or placental hematoma infarction is made, your provider will most likely start nonstress tests (NSTs) and biophysical profiles (BPPs) to follow the well being of the fetus. It is possible that the fetus may have to be delivered early if there is fetal compromise. Your provider may also start intramuscular steroids (betamethasone) to accelerate the fetal lung maturity. Your provider will also ask you to monitor the infant’s movements, and inform him of decreased fetal activity as decreased fetal movement may be indicative of fetal compromise.
Treatment for a placental hematoma infarction does not exist although the idea of using low molecular heparin and low dose aspirin to treat this condition is being investigated.
Illnesses that can be associated with placental infarction include hypertension as mentioned previously, post-term pregnancies (usually defined as 42 wks gestation or beyond), retroplacental hemorrhage like a placental abruption, preeclampsia or toxemia, certain autoimmune diseases like lupus or scleroderma, diabetes, and anticardiolipin antibodies.
Recurrent spontaneous abortions or miscarriages have been associated with placental infarcts in the first and second trimesters while fetal death and intrauterine growth retardation have been seen in the third trimester.
Placental infarction does not necessarily mean a cesarean section. It is still possible to deliver vaginally as long as the fetus can tolerate labor.
Remember to discuss the implications of a placental infarction or placental hematoma infarction with your provider if the diagnosis is made.
Wishing you a problem free and enjoyable delivery, Pablo.