Placental Insufficiency

What is Placental Insufficiency?

Placental insufficiency, or poor functioning of the placenta, is linked to various pregnancy-related issues like pre-eclampsia and intrauterine growth restriction (IUGR). Both of these conditions can increase the risk of premature labor, which is a significant contributor to the health issues and mortality rates seen in newborns globally. Even though the term placental insufficiency is commonly used in the medical field, there is some debate about its specific characteristics and a standard definition.

This lack of clarity causes difficulties when discussing or studying placental insufficiency. Nevertheless, most understand it as a gradual decline in how efficiently the placenta functions. This decrease means the placenta transfers less oxygen and nutrients to the unborn baby, ultimately leading to a lack of oxygen and acid build-up in the baby’s blood. This situation can cause the baby to decrease its metabolic needs to save the nutrients it can access, which may result in slowed growth while in the womb.

From a microscopic perspective, doctors can identify placental insufficiency if there are certain changes in the placenta, such as scarring, clotting, infarctions (tissue dying due to lack of blood supply), fibrin (a protein that helps blood clot) deposits, or decreased number and surface area of the villous capillary tree (the structure within the placenta that supports blood flow to the baby).

Even though placental infarctions can be found in around 25% of typically progressing pregnancies, increased occurrences are related to placental insufficiency and in turn, IUGR. Imaging studies like MRI and ultrasound used to detect placental insufficiency can show reduction in placental area and volume, increased thickness, and a rounder shape of the placenta.

What Causes Placental Insufficiency?

The underlying causes of an issue called “placental insufficiency” are not fully understood and research is still ongoing. Placental insufficiency is when the placenta (the organ that provides oxygen and nutrients to the baby during pregnancy) doesn’t work as well as it should. However, there are some known risk factors in mothers that may lead to this condition.

These risk factors include having a condition called pre-eclampsia or another blood pressure disorder, smoking, using drugs like cocaine or heroin, drinking alcohol, being a first-time mother, being older during pregnancy, and having previously given birth to a baby who wasn’t growing properly in the womb – this is called IntraUterine Growth Restriction (IUGR).

Studies have shown that mothers who smoked during pregnancy had changes in how blood flows in their placental vessels. This suggests that exposure to nicotine can change the blood vessels in the placenta. Any condition in the mother that can reduce the circulation of blood to the fetus can potentially lead to placental insufficiency.

Some medications, such as cancer drugs (antineoplastic), seizure drugs (anticonvulsants), or blood thinners (anti-coagulants) can also affect the growth of the fetus. Similarly, significant differences in the mother’s body weight, including malnutrition, can also lead to IUGR.

Another important finding is that complications in IUGR pregnancies indicate an issue with the transformation of the blood vessels in the placenta early in the pregnancy. These can be detected by a particular type of ultrasound called a Doppler ultrasound that examines blood flow in the womb.

Risk Factors and Frequency for Placental Insufficiency

Prematurity, or being born early, is the main cause of death for newborns. Another issue is intrauterine fetal growth restriction (IUGR), which means the baby doesn’t grow as much as it should in the womb. This problem happens in about 4% to 6% of pregnancies. Placental insufficiency, which is when the placenta doesn’t work properly, can cause preterm labor, pre-eclampsia, IUGR, and stillbirth. This affects about 10 to 15% of pregnancies.

IUGR makes it 3 times more likely for a baby to be born early compared to babies who are growing normally in the womb.
If a baby has IUGR, the risk of death for the baby after birth increases 5 to 6 times.
About half of the newborn babies with IUGR aren’t diagnosed until after they’re born.

Signs and Symptoms of Placental Insufficiency

Insufficient blood supply to the placenta, also known as placental insufficiency, can potentially result in Intrauterine Growth Restriction (IUGR). This condition affects neonates or newborn babies. Babies born with IUGR may either be born prematurely and are extremely low in weight, or they may have different body proportions at birth. These differences depend on when the disruption in blood supply happened. Signs of IUGR like reduced placental size can usually be seen at around 26 weeks of pregnancy during specific medical tests called Doppler studies.

If doctors suspect that a fetus might have IUGR, perhaps because of problems with the placenta or other reasons, they often recommend regular check-ups using a combination of Doppler studies and another type of test called a biophysical profile. This duo of tests allows doctors to detect a decline in the baby’s performance due to placental issues. Doppler studies can show an unusual pattern in the form of notching in the uterine arteries and increased resistance in the umbilical artery. As the issue worsens, it can lead to either missing or reversed blood flow during end-diastole – a specific phase of the heartbeat.

The fetus could also show non-reactive heart rate tracing during a biophysical profile, which is an early sign of potential distress. The fetus might also display:

Poor or no body movements
Difficulty in breathing
Loss of muscle tone

Such changes in Doppler status and biophysical profile could signal fetal distress, which is quite common with placental insufficiency. In severe cases, it could indicate the need for immediate delivery.

Testing for Placental Insufficiency

At present, there’s no standard method or criteria to diagnose placental insufficiency, a condition where the placenta doesn’t deliver enough nutrients and oxygen to the baby. This is part due to various terms being used for this condition. With advancing technology, however, Doppler ultrasound, a test that uses sound waves to “see” how blood flows, has proven valuable in evaluating the circulation of blood between the fetus and the placenta.

There’re four main types of Doppler techniques which help monitor the baby-mother blood flow: umbilical artery studies, uterine artery studies, middle cerebral artery studies, and ductus venosus studies. These tests can pick up various changes in blood flow as the baby grows and progresses towards birth.

Prior to pregnancy, the uterine arteries have low blood flow during diastole (when the heart is at rest), high resistance, and they bounce back in early diastole. Successful pregnancy involves the removal of smooth muscle of the blood vessels so these vessels can handle large quantities of blood with low resistance and no elasticity. Doppler ultrasound can show this change which normally occurs quickly, by around 12 weeks, and by 20 weeks or even earlier, resistance is low. If this transformation isn’t successful, resistance remains high, and this is associated with complications like intrauterine growth restriction (slow growth of the baby), pre-eclampsia, and fetal death. The uterine artery Doppler ultrasound can help identify these risky situations with about 85% sensitivity.

As the placenta’s resistance to blood flow rises, the umbilical artery Doppler studies can show different blood flow patterns. High resistance is normal in early pregnancy so absent blood flow on the Doppler is expected up to 12-14 weeks. However, if the resistance persists throughout pregnancy, it’s a sign of placental insufficiency.

Doppler studies of the middle cerebral artery (MCA) provide valuable additional information. MCA represents the blood flow status in the baby’s brain. The increase in diastolic flow (blood flow when the heart is at rest) and a decline in the pulse rate suggest placental disease and potential fetal compromise.

Venous Doppler, another form of Doppler technique, provides information related to the baby’s heart when the fetus is stressed. It has several benefits and can be easily imaged from as early as 12 weeks till about 40 weeks. If there’s an abnormality in the venous Doppler, it can signal fetal heart problems and severe placental insufficiency.

MRI imaging is another tool that can help with diagnosing placental insufficiency. In a T2-weighted Rapid Acquisition with Relaxation Enhancement imaging, decreased flow voids (areas with lost MRI signals usually seen where blood is flowing rapidly) between the placenta and uterus suggests decreased perfusion (delivery of blood). Other placental abnormalities, such as hemorrhages (bleeding) and infarctions (dead tissue due to lack of blood) can also be seen on MRI, which can signal a high risk of placental insufficiency.

Treatment Options for Placental Insufficiency

At present, there is no concrete treatment for placental insufficiency, a condition where the placenta does not work as effectively as it should. The only generally accepted solution is to deliver the baby if it is safe to do so based on how far the pregnancy has progressed. Some treatments, such as low-dose aspirin and antioxidant therapies like vitamins C and E, have shown promise in improving the condition of the placenta.

Research has shown that early use of Doppler ultrasound, a test that uses sound waves to create images and sounds of the baby inside the womb, can reduce perinatal mortality (the risk of death around the time of delivery) by almost 38% in cases where restricted baby growth is suspected during pregnancy.

Doppler ultrasound screening can also benefit high-risk women, including those with chronic hypertension (long-term high blood pressure), coagulopathies (blood clotting disorders), or a history of pre-eclampsia (a pregnancy disorder characterized by high blood pressure and organ damage). It is especially helpful if done between the 12th and the 14th weeks of pregnancy as it can detect signs of potential problems with the placenta, which could indicate the need for low-dose aspirin therapy.

In laboratory studies, heparin, a medication that prevents blood clots, has shown potential to stimulate the growth of new blood vessels and improve blood flow in the placenta. Among its various benefits, heparin can promote the growth of trophoblasts (cells that form the outer layer of a blastocyst during early pregnancy), reduce inflammation, and act as a growth factor.

Additionally, heparin has been found to increase the activity of certain proteins that play crucial roles in the development and functioning of the placenta. Thus, preliminary data suggest that heparin may have potential as a preventative treatment for diseases of the placenta.

The health issue known as placental insufficiency can be caused by many factors and can often lead to a condition called Intrauterine Growth Restriction (IUGR), where a baby doesn’t grow at a normal rate inside the womb. However, it can sometimes be challenging to distinguish a baby who is just small for their gestational age (SGA) from one who has IUGR.

Doppler studies, which examine blood flow, can be really beneficial here. Particularly Doppler studies of the umbilical artery can help tell apart IUGR and SGA babies. This is significant because it directs which pregnancies need more vigilant observation as opposed to standard monitoring.

When a fetus’s estimated average weight is below the 10th percentile for its gestational age, it is referred to as SGA. On the other hand, IUGR is usually a result of placental insufficiency, a genetic disorder, or an infection, which prevents a fetus from reaching normal growth rates.

Therefore, an SGA baby is small but healthy, while an IUGR baby may be small and have health problems.

When thinking about the causative factors of placental insufficiency, consider associated conditions, which include, but are not limited to:

Preeclampsia
Maternal hypertensive disorders
Oligohydramnios (low amniotic fluid)
Maternal malnutrition or calorie restriction.

Both preeclampsia and maternal hypertensive disorders can affect the resistance of the placenta and the flow of blood between the uterus and placenta.

What to expect with Placental Insufficiency

If a baby is smaller than usual while growing in the womb due to an unhealthy placenta (a condition known as Intrauterine Growth Restriction or IUGR), and they survive the period around childbirth, they may face higher risks later in life. Compared to a baby that grows normally, a baby with IUGR is at a greater risk of developing cognitive problems in childhood, which could include conditions like cerebral palsy and seizure disorders.

A common sign of an unhealthy placenta is abnormal umbilical artery Doppler flow velocity waveforms (DFVWs), which are measurements of blood flow from the placenta to the baby. One study found that babies with abnormal DFVWs due to unhealthy placentas had lower IQs at five years old compared to those with healthy placentas.

IUGR in infancy may also contribute to the risk of chronic illnesses later in life, including coronary artery disease, high blood pressure, and diabetes. Therefore, the best chances for a healthy future for these babies should focus on interventions that maximize the length of the pregnancy.

It’s estimated that each additional week of pregnancy for babies between 24 and 28 weeks gestation increases the chance of survival without related health issues by about 10% to 15%.

Possible Complications When Diagnosed with Placental Insufficiency

: When the placenta doesn’t work properly, it can lead to a variety of complex problems for the fetus. It can lead to difficulties with the placenta carrying oxygen (placental respiratory failure) and a decrease in the amount of oxygen getting to the fetus (fetal hypoxemia). Both of these issues can hinder the baby’s growth, sometimes leading to a premature birth.

The worst scenario occurs when the placenta does not form at all, leading to a miscarriage. Besides, an ultrasound of the blood vessels in the umbilical cord could show abnormalities that are linked to a range of problems in the baby. These problems can include a high level of acid in the baby’s blood, needing resuscitation, medications to increase the blood pressure, help with breathing, or multiple organ failure.

This usually happens when there’s not enough oxygen supplied to the baby. It triggers a shift in blood distribution towards vital organs like brain and heart, neglecting others organs like the intestines and kidneys.

Frighteningly, lack or reverse flow of blood seen in ultrasound studies can suggest a higher chance of the newborn experiencing brain hemorrhage. As pregnancy progresses and placenta issues increase, the already undersized baby becomes even more at risk for low blood sugar, brain damage due to lack of oxygen, low platelet count, white cell count, and anemia.

Worrying signs:

Lack of oxygen leading to baby’s slowed growth
Premature birth
Need for resuscitation and medications
Potential brain hemorrhage in newborns
Multisystem organ failure
Low blood sugar
Brain damage due to lack of oxygen
Low platelet, white cell count, and anemia
Increased risk for miscarriage

More frighteningly, research suggests that these babies may be more likely to have learning problems as children, and get chronic diseases when they’re adults.

Preventing Placental Insufficiency

Regular check-ups and ultrasound scans are incredibly important when a woman is pregnant, as they help guarantee the best health outcomes for the newborn baby. Although there’s no surefire way to prevent placental insufficiency (a condition where the placenta doesn’t deliver enough oxygen. and nutrients to the baby), once it’s been detected through an ultrasound, MRI, or BPP (a test that measures the baby’s health in the womb), proactive steps like starting treatment with a medication called heparin can help. The aim of the treatment is to extend the pregnancy which can help prevent complications like IUGR (a condition where the baby doesn’t grow at the normal rate in the womb), premature birth, or loss of the baby. However, more research is needed to understand the best interventions and treatments, and at what point in the pregnancy they can most benefit the baby.

Frequently asked questions

Placental insufficiency is a condition characterized by a gradual decline in the efficiency of the placenta, resulting in a decreased transfer of oxygen and nutrients to the unborn baby. This can lead to a lack of oxygen, acid build-up in the baby's blood, and slowed growth in the womb. Doctors can identify placental insufficiency through certain changes in the placenta, such as scarring, clotting, infarctions, fibrin deposits, or decreased number and surface area of the villous capillary tree.

Placental insufficiency affects about 10 to 15% of pregnancies.

Signs and symptoms of Placental Insufficiency, also known as Intrauterine Growth Restriction (IUGR), include: - Neonates or newborn babies born with IUGR may be born prematurely and have extremely low weight. - Babies with IUGR may have different body proportions at birth, depending on when the disruption in blood supply occurred. - Reduced placental size can usually be seen at around 26 weeks of pregnancy during specific medical tests called Doppler studies. - Doctors often recommend regular check-ups using a combination of Doppler studies and a biophysical profile if they suspect a fetus might have IUGR. - Doppler studies can show an unusual pattern, such as notching in the uterine arteries and increased resistance in the umbilical artery. - The fetus might show non-reactive heart rate tracing during a biophysical profile, which is an early sign of potential distress. - Other signs and symptoms of fetal distress due to placental insufficiency include poor or no body movements, difficulty in breathing, and loss of muscle tone. - Changes in Doppler status and biophysical profile can signal fetal distress, which is common with placental insufficiency. - In severe cases, fetal distress due to placental insufficiency may indicate the need for immediate delivery.

The underlying causes of Placental Insufficiency are not fully understood, but there are known risk factors that may lead to this condition. These risk factors include conditions like pre-eclampsia or other blood pressure disorders, smoking, drug use (such as cocaine or heroin), alcohol consumption, being a first-time mother, being older during pregnancy, and having previously given birth to a baby who had Intrauterine Growth Restriction (IUGR).

The conditions that a doctor needs to rule out when diagnosing Placental Insufficiency include: - Preeclampsia - Maternal hypertensive disorders - Oligohydramnios (low amniotic fluid) - Maternal malnutrition or calorie restriction.

The types of tests that are needed for diagnosing placental insufficiency include: 1. Doppler ultrasound: - Umbilical artery studies - Uterine artery studies - Middle cerebral artery studies - Ductus venosus studies 2. MRI imaging: - T2-weighted Rapid Acquisition with Relaxation Enhancement imaging These tests help evaluate the circulation of blood between the fetus and the placenta, monitor blood flow patterns, and detect abnormalities such as decreased perfusion, hemorrhages, and infarctions. Additionally, Doppler ultrasound screening can be beneficial for high-risk women, especially if done between the 12th and 14th weeks of pregnancy.

At present, the only generally accepted solution for treating placental insufficiency is to deliver the baby if it is safe to do so based on how far the pregnancy has progressed. However, some treatments such as low-dose aspirin and antioxidant therapies like vitamins C and E have shown promise in improving the condition of the placenta. Additionally, early use of Doppler ultrasound screening can help detect signs of potential problems with the placenta, and heparin, a medication that prevents blood clots, has shown potential in stimulating the growth of new blood vessels and improving blood flow in the placenta.

When treating Placental Insufficiency, there are no specific side effects mentioned in the given text. However, it is important to note that the condition itself can lead to a variety of complex problems for the fetus, including slowed growth, premature birth, the need for resuscitation and medications, potential brain hemorrhage in newborns, multisystem organ failure, low blood sugar, brain damage due to lack of oxygen, low platelet and white cell count, anemia, and an increased risk for miscarriage. Additionally, research suggests that these babies may be more likely to have learning problems as children and develop chronic diseases as adults.

The prognosis for placental insufficiency can vary depending on the severity of the condition and the interventions taken. However, it is generally associated with increased risks for preterm labor, pre-eclampsia, intrauterine growth restriction (IUGR), and stillbirth. Babies with IUGR are at a higher risk of being born early and facing cognitive problems in childhood, as well as an increased risk of chronic illnesses later in life. Maximizing the length of the pregnancy can improve the chances of a healthier future for these babies.

An obstetrician or a maternal-fetal medicine specialist.

Eclampsia/Preeclampsia Intrauterine Growth Restriction Placenta Pregnancy Women's Health