The placenta is an organ that grows in the womb during pregnancy. Placental insufficiency (also called 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. This blood flow disorder is marked by a reduction in the mother’s blood supply. The complication can also occur when the mother’s blood supply doesn’t adequately increase by mid-pregnancy.
When the placenta malfunctions, it’s 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. This can lead to low birth weight, premature birth, and birth defects. It also carries increased risks of complications for the mother. Diagnosing this problem early is crucial to the health of both mother and baby.
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. It 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 they never actually mix.
The placenta’s primary jobs are to:
- move oxygen into the baby’s bloodstream
- carry carbon dioxide 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. The American Pregnancy Association estimates that the placenta weighs 1 to 2 pounds at the time of birth.
The placenta is removed during labor. According to the Mayo Clinic, it’s delivered between 5 and 30 minutes after the baby.
Placental insufficiency is linked to blood flow problems. While maternal blood and vascular disorders can trigger it, medications and lifestyle habits are also possible triggers.
The most common conditions linked to placental insufficiency are:
- chronic high blood pressure (hypertension)
- 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).
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. The fetus may also be moving less than expected.
If the baby isn’t growing properly, the mother’s abdomen will be small, and the baby’s movements will not be felt much.
Vaginal bleeding or preterm labor contractions may occur with placental abruption.
Placental insufficiency is not usually considered life-threatening to the mother. However, the risk is greater if the mother has hypertension or diabetes.
During pregnancy, the mother is more likely to experience:
- preeclampsia (elevated blood pressure and protein in the urine)
- placental abruption (placenta pulls away from the uterine wall)
- preterm labor and delivery
The symptoms of preeclampsia are excess weight gain, leg and hand swelling (edema), headaches, and high blood pressure.
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 risk of oxygen deprivation at birth (can cause cerebral palsy and other complications)
- learning disabilities
- low body temperature (hypothermia)
- low blood sugar (hypoglycemia)
- too little blood calcium (hypocalcemia)
- excess red blood cells (polycythemia)
- premature labor
- cesarean delivery
Getting proper prenatal care 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 nonstress 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.
A maternity care plan may recommend:
- education on preeclampsia, 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 preeclampsia or intrauterine growth restriction (IUGR) become severe.
Placental insufficiency can’t be cured, but it can be managed. It’s extremely important to receive an early diagnosis and adequate prenatal care. These can improve the baby’s chances of normal growth and decrease the risk of birth complications. According to Mount Sinai Hospital, the best outlook occurs when the condition is caught between 12 and 20 weeks.