Placental insufficiency, also known as placental dysfunction or uteroplacental vascular insufficiency, is an uncommon but serious complication of pregnancy. It occurs when the placenta does not develop properly, or is damaged.
The placenta is an organ that grows in the womb during pregnancy. When the placenta malfunctions, it is unable to supply adequate oxygen and nutrients to the baby from the mother’s bloodstream. Without this vital support, the baby cannot grow and thrive.
Placental insufficiency is a blood flow disorder. It is marked by a reduction in the mother’s blood supply, and/or the failure of the blood supply to increase adequately by mid-pregnancy.
Placental insufficiency can lead to low birth weight, premature birth, and birth defects. It also carries increased risks of complications for the mother.
It is important to diagnose this problem early and get proper prenatal care.
Vital Functions of the Placenta
The placenta is a highly complex biological organ. It forms and grows where the fertilized egg attaches to the wall of the uterus.
The umbilical cord grows from the placenta to the baby’s navel. The umbilical cord allows blood to flow from mother to baby, and back again. The mother’s blood and the baby’s blood are filtered through the placenta, but never actually mix.
The placenta’s primary jobs are to:
- move oxygen into the baby’s bloodstream
- carry carbon monoxide away
- pass nutrients to the baby
- transfer waste for disposal by the mother’s body
The placenta has an important role in hormone production as well. It also protects the fetus from harmful bacteria and infections.
A healthy placenta continues to grow throughout the pregnancy. It weighs about 1.5 lbs. at the time of birth.
Causes of Placental Insufficiency
Placental insufficiency is linked to blood flow problems, and maternal blood and vascular disorders can trigger it. Certain medications and unhealthy habits can also cause it.
The most common conditions linked to placental insufficiency are:
- chronic high blood pressure
- blood clotting disorders
- certain medications (particularly blood thinners)
- drug abuse (especially cocaine, heroin, and methamphetamine)
Placental insufficiency may also occur if the placenta doesn’t attach properly to the uterine wall, or if the placenta breaks away from it (placental abruption).
Placental Insufficiency Risks
Placental insufficiency is not usually considered life threatening to the mother. However, if she has high blood pressure or diabetes, the risks increase.
During pregnancy, the mother is more likely to experience:
- pre-eclampsia (elevated blood pressure and protein in the urine)
- placental abruption (placenta pulls away from the uterine wall)
- preterm labor and delivery
The symptoms of pre-eclampsia are excess weight gain, leg and hand swelling (edema), headaches and high blood pressure.
If the baby is not growing properly, the mother’s abdomen will be small, and the baby’s movements will not be felt much.
Vaginal bleeding or pre-term labor contractions may occur with placental abruption.
The earlier in the pregnancy that placental insufficiency occurs, the more severe the problems can be for the baby. The baby’s risks include:
- greater chance of death during delivery
- greater risk of oxygen deprivation at birth (can cause cerebral palsy and other complications)
- greater chance of learning disabilities
- intrauterine growth restriction (IUGR) (low weight in the womb; specifically, the baby weighs 90 percent less than he or she should) (National Institutes of Health)
- hypothermia (low body temperature)
- hypoglycemia (low blood sugar)
- hypocalcemia (too little calcium in the blood)
- polycythemia (excess red blood cells)
- premature labor
- cesarean delivery
According to a 2007 study by the American College of Obstetrics & Gynecology, birth defects occurred in nearly 40 percent of infants affected by early-onset placental insufficiency.
Sadly, the most common birth defects seen in this study were:
- lung disease
- brain hemorrhage
- gastrointestinal disease
According to the study, approximately 20 percent of the babies did not survive (Baschat et al.).
Symptoms of Placental Insufficiency
There are no maternal symptoms associated with placental insufficiency. However, certain clues can lead to early diagnosis. The mother may notice that the size of her uterus is smaller than in previous pregnancies. Additionally, the fetus may be moving less than expected.
Diagnosis and Management of Placental Insufficiency
Getting proper prenatal care beginning at 12 weeks can lead to an early diagnosis. This can improve outcomes for the mother and the baby.
Tests that can detect placental insufficiency include:
- pregnancy ultrasound to measure the size of the placenta
- ultrasound to monitor the size of the fetus
- alpha-fetoprotein levels in the mother’s blood (a protein made in the baby’s liver)
- fetal non-stress test (involves the wearing of two belts on the mother’s abdomen and sometimes a gentle buzzer to wake the baby) to measure the baby’s heart rate and contractions
Treating maternal high blood pressure or diabetes can help improve the baby’s growth.
The plan of maternity care may recommend:
- education on pre-eclampsia, as well as self-monitoring for the disease
- more frequent doctor visits
- bed rest to conserve fuel and energy for the baby
- consultation with a high-risk maternal fetal specialist
You may need to keep a daily record of when the baby moves or kicks.
If there is concern about premature birth (32 weeks or earlier), the mother may receive steroid injections. Steroids dissolve through the placenta and strengthen the baby’s lungs.
You may need intensive outpatient or inpatient care if pre-eclampsia or IUGR become severe.
Placental insufficiency cannot be cured, but it can be managed. It is extremely important to receive an early diagnosis and adequate prenatal care. These can improve the baby’s chances of normal growth and decrease the risks of birth complications.