The placenta is a vital organ that develops during pregnancy to provide oxygen and nutrients to the growing baby. It attaches to the wall of the uterus and connects to the baby through the umbilical cord. A healthy placenta is essential for a healthy pregnancy. However, various problems can affect the placenta, causing potentially serious complications. Being aware of the signs of placenta issues can help pregnant women identify problems early and get the necessary treatment.
Bleeding in pregnancy
One of the most common and obvious signs of a potential placenta problem is vaginal bleeding during pregnancy. Any bleeding after the first trimester is abnormal and requires immediate medical attention. Causes of bleeding may include:
- Placenta previa – The placenta covers part or all of the cervix, causing bleeding as the cervix effaces and dilates in preparation for labor.
- Placental abruption – The placenta separates prematurely from the uterine wall, causing the maternal blood vessels to hemorrhage.
- Vasa previa – Fetal blood vessels embedded in the membranes rupture, causing bleeding.
Bleeding in pregnancy should never be ignored. Even small amounts of blood could signal a significant issue. Emergency medical care is crucial to evaluate the cause and treat any complications.
Preterm labor
Going into labor before 37 weeks gestation may be linked to placental problems. Potential causes include:
- Placental insufficiency – The placenta cannot deliver enough oxygen and nutrients to the fetus, prompting early labor.
- Placental abruption – Premature separation leads to reduced blood flow, stimulating contractions.
- Chronic inflammation – Infections and clotting problems can cause inflammation and damage in the placenta.
Preterm labor associated with placenta issues tends to occur after 20 weeks. Contractions may be accompanied by low back pain or pelvic pressure. Stomach cramps and increased vaginal discharge are other symptoms. Preterm labor signals a high-risk pregnancy requiring intensive monitoring and steroids for fetal lung development.
Fetal growth problems
The placenta supplies everything the developing baby needs to grow. Placental dysfunction can result in abnormal fetal growth:
- IUGR: Intrauterine growth restriction (IUGR) refers to poor growth and low birth weight due to placental insufficiency.
- Macrosomia: Uncontrolled gestational diabetes or obesity can prompt the placenta to oversupply nutrients, causing excessive growth (macrosomia).
Abdominal palpation and ultrasound are used to estimate fetal size and growth trajectory. Small or large measurements indicate the need for additional testing and monitoring.
High blood pressure
The placenta plays a role in regulating maternal blood pressure. Problems can lead to high blood pressure (hypertension):
- Preeclampsia: Damaged placenta vessels cause widespread inflammation. This results in high blood pressure, organ damage, and excess protein in the urine.
- Gestational hypertension: Elevated pressures without protein in the urine or organ problems, may signal placental dysfunction.
High blood pressure in pregnancy requires strict control to prevent complications. Repeat monitoring, blood and urine tests, and possibly early delivery will be recommended.
Decreased fetal movement
Active baby movement is a sign of fetal well-being. Decreased fetal movement may indicate:
- Poor oxygen and nutrient supply due to placental aging or damage.
- Cord compression from low amniotic fluid levels.
- Impaired blood flow from placental abruption or previa.
Counting fetal kicks and being aware of normal movement patterns is important. Noticeable decreases warrant immediate medical assessment to check placental function and amniotic fluid levels.
Oligohydramnios
The amniotic fluid that cushions the baby is mainly produced by the placenta. Oligohydramnios refers to low fluid levels, which can result from:
- Placental insufficiency reducing fluid production.
- Premature rupture of membranes (PROM).
- Fetal urinary tract defects or poor kidney function.
- Maternal dehydration.
Oligohydramnios limits fetal movement and can cause umbilical cord compression. It is diagnosed through ultrasound and may prompt induction of labor if the pregnancy is past 34 weeks gestation.
High AFP levels
Alpha-fetoprotein (AFP) is a protein produced by the fetal liver and placenta. Levels can be measured through maternal blood tests:
- Low AFP may signal placenta or umbilical cord problems impacting fetal growth and development.
- High AFP can indicate placental damage, twins, birth defects, or gestational diabetes.
Abnormal AFP typically warrants further testing like ultrasound or amniocentesis to identify potential causes and determine appropriate care.
Placental calcification
Calcium deposits in the placenta often appear later in pregnancy as the organ ages. However, premature calcification can restrict function. Causes include:
- Maternal medical conditions like hypertension, diabetes, or kidney disease.
- Placental inflammation from infections or clotting disorders.
- Fetal growth problems.
- Prior placental damage.
Calcification is diagnosed through ultrasound. Extensive placental calcification may prompt earlier delivery to prevent worsening limitations to blood flow and nutrient transport.
Placental tumors
Abnormal placental cell growth can very rarely result in benign or cancerous tumors such as:
- Chorioangiomas – Benign tumors made up of excess blood vessels.
- Teratomas – Tumors containing abnormal tissues like hair, muscle, or bone.
- Choriocarcinoma – Malignant masses that can spread cancer cells.
Large tumors may impact nutrient delivery to the fetus. Cancerous growths require chemotherapy or surgical removal, even if pregnancy termination is necessary.
Placenta accreta spectrum
Placenta accreta occurs when tissues attach too deeply into the uterine wall. Variations include:
- Accreta – Attachment to uterus only.
- Increta – Invasion into uterine muscle.
- Percreta – Penetration through the uterus.
Risk factors include prior cesarean sections and placental previa in later pregnancies. This can cause severe bleeding during pregnancy and delivery.
Retained placenta
After delivery, the placenta should detach from the uterine wall and deliver spontaneously within 30 minutes. A retained placenta can lead to:
- Heavy maternal bleeding.
- Infection.
- Hemorrhage.
- Need for blood transfusion or hysterectomy.
If the placenta does not birth after 30-60 minutes, manual removal or medication to stimulate contractions may be required.
Placenta examination after delivery
All delivered placentas are examined for problems like:
- Retained fragments – Pieces left attached to the uterus.
- Thrombosis or clots – Blockages in blood flow.
- Hematoma or bleeding – Blood pooled under the membranes.
- Infarcts – Areas of dead tissue impeding function.
- Calcification – Calcium buildup limiting transport.
- Abnormal shape – Indicating abnormalities.
Identifying placental problems guides postpartum care to treat complications like infection, blood loss, or clotting issues.
Cord abnormalities
The umbilical cord carries oxygen and nutrients between baby and placenta. Problems include:
- True knots – Can tighten and block flow.
- Short cord – Causes tension and potential cord accidents.
- Prolapse – Cord delivers before the baby, risking compression.
- Vasa previa – Exposed vessels rupture, resulting in bleeding.
- Velamentous insertion – Cord inserts into membranes rather than placenta.
Cord issues may produce variable fetal heart rate patterns, decreased movement, or poor growth. Ultrasound and monitoring helps identify abnormalities for pregnancy management.
Maternal risk factors
Certain maternal health factors raise the risk of placenta complications:
- Advanced maternal age – Over 35 years old.
- Smoking or substance abuse.
- Multiple gestation pregnancy – Twins, triplets, etc.
- Assisted reproduction techniques – IVF, IUI.
- Malnutrition or poor weight gain.
- Chronic hypertension or diabetes.
- Kidney or cardiovascular disease.
- Autoimmune disorders like lupus.
- Thrombophilia clotting disorders.
- Prior uterine surgery like cesarean section or myomectomy.
High-risk women need closer monitoring throughout pregnancy to catch placental abnormalities. Managing underlying health conditions also helps prevent problems.
History of placenta issues
Some conditions associated with placental dysfunction have higher recurrence rates in subsequent pregnancies. These include:
- Prior premature delivery or IUGR.
- Preeclampsia or placental abruption.
- Placenta previa.
- Placenta accreta.
- Retained placenta requiring manual removal.
- Stillbirth potentially linked to placental causes.
If prior pregnancies had definite or possible placental complications, closer surveillance and preventive care is warranted in following pregnancies.
Conclusion
The placenta is essential for nurturing a growing fetus, and placental problems can have serious repercussions. Being aware of potential signs of placental dysfunction empowers pregnant women to speak up about concerning symptoms. This allows their healthcare providers to initiate appropriate testing and interventions when needed. Catching placental abnormalities early optimizes the chances of a healthy pregnancy and delivery outcome.