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placental insufficiency Images (Click to view larger image)
Alternative Names
placental dysfunction
Definition
Placental insufficiency is the failure of the placenta to supply nutrients to the foetus and remove toxic wastes.
What is going on in the body?
When the placenta fails to develop or function properly, the foetus cannot grow and develop normally. The earlier in the pregnancy that this occurs, the more severe the problems. If placental insufficiency occurs for a long time during the pregnancy, it may lead to intrauterine growth retardation (IUGR).
What are the signs and symptoms of the condition?
There are usually no symptoms with placental insufficiency. However, a mother may notice that the size of her uterus is smaller than in previous pregnancies. The foetus may also be moving less than expected.
What are the causes and risks of the condition?
Between 3 to 7% of all pregnancies are complicated by IUGR due to placental insufficiency. A low birth weight may be suspected if the size of the woman's uterus is smaller than what is expected for each week of pregnancy. The woman has a higher risk of having a child with IUGR if the following are present: - defects of the placental membranes
- defects of the umbilical cord
- abnormal implantation of the placenta in the uterus
- a break in the placental membrane that causes the baby's blood to mix with the mother's blood
- Rh incompatibility, a condition in which the mother's blood is not compatible with the baby's blood
- being pregnant with twins or triplets
- previous low-birth-weight infant
- long-term high blood pressure
- diabetes
- severe kidney disease
- heavy smoking
- insufficient weight gain by the mother during pregnancy, defined as less than 4.5 kg
- preeclampsia or eclampsia, conditions which raise the mother's blood pressure
- high altitude
- drug addiction, such as addiction to cocaine
- blood thinners such as warfarin
- immunosuppressive medications
- human immunodeficiency virus (HIV) infection in the mother
- alcohol abuse
- infection with cytomegalovirus, toxoplasmosis, rubella, or syphilis, known collectively as TORCH infections
- poor nutrition of the mother
- infant with known birth defects or chromosome abnormalities
- frequent vaginal bleeding due to placenta praevia, a condition in which the placenta is attached to the uterus over or near the cervix
- certain blood disorders in the mother, such as sickle cell anaemia or thalassaemia
- premature placental separation, known as placental abruption
What can be done to prevent the condition?
Most cases of placental insufficiency and IUGR cannot be prevented. However, there are several tests that can be done early in pregnancy to help detect problems. These include: Pregnant women can also do the following to help prevent these conditions: Before becoming pregnant, women should follow a healthy diet that contains folate. This can help to decrease the rate of certain foetal anomalies.
How is the condition diagnosed?
Pregnancy ultrasounds can be used to check on the growth of the foetus and placenta. It is important that this condition be diagnosed early in the pregnancy. This is to prevent the serious complications that may arise for the baby during labour as well as in later life.
What are the long-term effects of the condition?
Long-term effects of placental insufficiency depend on the underlying cause. During the pregnancy a mother may be restricted to bed and have to take several precautions.
The long-term effects for the a baby born following placenta insufficiency can be serious. After birth, he or she will tend to remain physically small. There is a higher risk for neurological and intellectual impairments. Major disabilities include severe mental retardation, cerebral palsy, and seizures.
What are the risks to others?
With placental insufficiency, there are many risks to the foetus during the pregnancy, at delivery, and after delivery. These risks include: What are the treatments for the condition?
To treat this condition, the doctor may recommend that the pregnant woman: - stop smoking
- stop taking illicit drugs, such as cocaine
- stop drinking alcohol
- eat a healthy diet that includes more than 10,000 kilojoules per day
- rest in bed during the day, lying on the left side as much as possible
- take low-dose aspirin to prevent tiny blood clots from forming in the placenta, as well as to dilate, or open, the blood vessels
- pay attention to the movement of the baby, any contractions, or rupture of the membranes ("breaking water") earlier than expected
- deliver in a hospital setting
- have the baby monitored electronically during labour
- use as little anaesthesia as possible and no narcotics during labour
- have a caesarean section or forceps delivery if foetal distress is detected
What are the side effects of the treatments?
The side effects of surgery include bleeding, infection, and allergic reaction to the anaesthesia . Medications have various side effects, including stomach upset, rash, and allergic reaction.
What happens after treatment for the condition?
Placental insufficiency is not considered life-threatening to the mother. However, she may be at risk for significant illness or even death if she has an underlying condition such as high blood pressure or diabetes.
Placental insufficiency may cause serious conditions in the newborn, such as pneumonia, cerebral palsy, or other respiratory problems. A newborn who is born prematurely or with serious medical conditions may need an incubator, a special enclosed bed that can control temperature and oxygen levels.
If a child is born with cerebral palsy, there may be disabilities that require therapy, use of appliances such as crutches or canes, and a daily struggle with medical problems. As the child gets older, there may be a need for special education programs for learning disabilities caused by oxygen and nutritional deprivation while in the uterus.
How is the condition monitored?
If testing later in pregnancy shows that the baby's lungs are mature, then labour should be induced and the baby delivered. The following tests should be done when the foetus is very premature or the lungs haven't matured fully: - nonstress testing performed weekly or biweekly, to monitor uterine contractions
- biophysical profile done weekly or biweekly
- Doppler umbilical artery waveforms, a special test for foetal health
- pregnancy ultrasound scans every 10 to 14 days
Author: Eva Martin, MD
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Contributors
Potential conflict of interest information for reviewers available on request |
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