Definition

Placental insufficiency, also known as placental dysfunction, is a medical condition in which oxygen and nutrients do not adequately reach the fetus through the placenta during pregnancy. This condition occurs in about 10% of pregnancies.

Placental insufficiency happens due to impaired placental development or damage to the placenta, which results in reduced placental function. As a result, blood flow through the placenta decreases, potentially leading to a reduced oxygen level in the fetus's body, a condition known as hypoxemia.

The placenta is a complex organ that forms in the uterus during pregnancy. It connects the fetus to the mother and is responsible for supplying the baby with oxygen and nutrients while removing waste products from the fetus's body.

Therefore, the placenta requires a high amount of energy and oxygen to support the growth of both the fetus and the placenta itself. Any disruption in nutrient intake due to placental insufficiency can lead to growth restriction in the fetus (Intrauterine Growth Restriction/IUGR). Additionally, the baby may be born prematurely or have congenital abnormalities.

Causes

The exact cause of placental insufficiency is not well understood. Normally, the placenta develops from a group of cells known as trophoblasts. To form a normal placenta, the trophoblasts attach to the uterine wall of the pregnant woman and develop structures resembling roots called villi.

Villi are structures in the placenta that serve as sites for the exchange of nutrients and waste between the mother and the fetus. The attachment of the placenta and the formation of villi lead to changes in the uterine blood vessels of the mother (remodeling), making them wider and larger, which increases blood flow from the mother to the fetus through the placenta.

If there is a disruption in the remodeling process of the uterine blood vessels, blood clots may form, and fibrin strands may deposit. This reduces the transfer of nutrients to the fetus. Additionally, a condition known as lateralization can occur, where the attachment of the placenta predominantly happens on one side, resulting in uneven blood distribution and disrupted nutrient delivery to the fetus.

Another condition that can cause placental insufficiency is placental abruption. In this condition, the placenta prematurely detaches from the uterus before delivery, leading to bleeding and impaired nutrient transfer from the mother to the fetus.

Risk Factor

Although the exact cause of placental insufficiency is not well known, several risk factors may contribute to this condition, including:

• Preeclampsia
• Smoking, alcohol consumption, and drug use during pregnancy
• Diabetes
• Multiple pregnancies (more than one fetus)
• First-time pregnancy
• Maternal age over 35 years
• History of previous pregnancies with intrauterine growth restriction (IUGR)
• Certain medications, such as cancer drugs (crizotinib and doxorubicin) and anticonvulsants (phenytoin and valproic acid)

Symptoms

Women with placental insufficiency rarely exhibit observable symptoms. A fetus that does not receive adequate nutrients tends to move less and be less active. The uterus may also feel smaller than in previous pregnancies, which can sometimes be noticed by the mother or detected by the doctor during a health checkup.

The most common sign of placental insufficiency is intrauterine growth restriction (IUGR), characterized by a fetus's size and weight not aligning with gestational age, preterm delivery (before 37 weeks), and fetal death. Placental abruption can also cause placental insufficiency, leading to vaginal bleeding.

Diagnosis

To diagnose placental insufficiency, your doctor will take a medical history and conduct a series of examinations. Currently, there is no universally recognized standard method for diagnosing placental insufficiency. However, in most cases, placental insufficiency can be diagnosed using Doppler ultrasound.

Doppler ultrasound is used to assess the amount of blood flowing through the vessels within the placenta, making it very useful for evaluating placental and fetal blood circulation. This examination is highly sensitive in detecting severe IUGR and preeclampsia. Regular screening using Doppler ultrasound is recommended for high-risk mothers (those with chronic hypertension, blood clotting disorders, or a history of preeclampsia) to detect potential complications early.

Another examination that can be performed is Magnetic Resonance Imaging (MRI). This test is conducted when a diagnosis cannot be confirmed through ultrasound. MRI can provide detailed images of the placental tissue, allowing for a definitive diagnosis of placental insufficiency.

Management

If your doctor suspects placental insufficiency, the growth of the fetus will be closely monitored. You may be asked to record or observe the baby's movements and immediately inform healthcare providers of any changes you notice.

Currently, there is no treatment known to cure placental insufficiency other than delivery. Therefore, gestational age becomes an important factor in choosing a treatment option, as delivery before 34 weeks of pregnancy can increase the risk of neonatal morbidity and mortality. For pregnancies less than 34 weeks, other therapeutic options are used to delay delivery.

If signs of placental insufficiency are detected on Doppler ultrasound before 34 weeks of pregnancy, low-dose aspirin and antioxidants like vitamins C and E may be used to improve placental conditions. The use of heparin, a blood thinner, can also prevent blood clot formation and stimulate blood vessel formation within the placenta, increasing placental blood flow.

Complication

Complications associated with placental insufficiency in the mother include:

• Preeclampsia
• Preterm delivery
• Intrauterine growth restriction (IUGR)
• Placental abruption, or premature separation of the placenta from its attachment site
• Increased risk of fetal death in utero

Placental insufficiency can also negatively affect the baby, leading to:

• Anemia
• Low blood sugar levels
• Low platelet count
• Reduced oxygen flow to the baby's brain
• Cognitive impairments

Prevention

You can avoid placental insufficiency by regularly attending checkups during pregnancy. This allows for early detection and management of placental insufficiency, especially in high-risk pregnant women. Avoid alcohol consumption, smoking, and drug use during pregnancy. Although placental insufficiency cannot be cured, it can be managed if detected early.

When to See a Doctor?

See a doctor immediately if you notice a decrease in fetal movements or if your uterus feels smaller than in previous pregnancies. You should also see a doctor if you experience vaginal bleeding.

Looking for more information about other diseases? Click here!