The placenta is an organ that develops in the uterine wall when a woman is pregnant. The critical functions of the placenta during pregnancy include the growth and development of the fetus (1). It is responsible for carrying the oxygen and nutrients to the fetus and removing the waste from the fetal blood.
A placenta is a life-supporting organ for the growing fetus; however, sometimes, its functions may be hindered due to several factors, such as blood clots, abdominal trauma, and blood pressure. These factors may lead to pregnancy complications.
This post informs you about the functions of the placenta, the problems related to it, the symptoms of such complications, and ways to reduce the risk.
Why Is The Placenta Important?
The placenta is your unborn baby’s life support system and plays a key role in its development. It connects the mother to the fetus through the umbilical cord and carries out the functions your fetus cannot perform by itself (2).
Functions Of The Placenta During Pregnancy
- Respiratory, excretory, nutritive, endocrine, barrier function, immunological function.
- Supplying oxygen and output of co2 is done via simple diffusion (respiratory) and nutrients to the fetus via the umbilical cord (nutritive).
- Clearing out waste products, such as urea, creatinine, uric acid from the fetus (excretory).
- Metabolizing and releasing food substances and required products into the maternal and fetal blood circulations.
- Protecting the fetus from xenobiotics (compounds including food additives, drugs, and environmental pollutants).
- Producing steroid and peptide hormones that help in the growth and development of the baby (endocrine).
- Protecting the fetus from infections (bacterial) and maternal diseases.
- Fetal membrane protects the transfer of noxious substances less than 500 dalton except antibody and antigen (barrier).
- Produces different enzymes such as diamine oxidase and oxytocinase (enzymatic).
Factors That Affect The Placental Function
Various factors can affect the placental function during pregnancy and make the mother prone to certain risks. They may include:
- Mother’s age: Mothers who conceive after the age of 35 are likely to experience placental problems (4).
- Twin or multiple pregnancies: Mothers carrying more than one baby are likely to develop a weak placenta. It may raise the risk of early placental detachment (5).
- Premature rupture of membranes: Your baby is usually cushioned and protected by the amniotic sac (fluid-filled membrane). If it breaks or leaks before labor, you may be at risk of placental infections (chorioamnionitis) and placental abruption (premature placental separation from the uterus) (6).
- Blood-clotting disorders: Blood clotting as a result of genetic susceptibility, obesity, increased maternal age, medical illnesses, prolonged immobility, etc., are likely to form inside the placenta too. It may, sometimes, cut off the blood supply, and pose danger to the baby (7).
- Abdominal trauma: A fall or any type of blow that causes abdominal trauma increases the risk of placenta abruption (8).
- Prior placental problems: If you have experienced any placental problems in your previous pregnancy, you might develop it again (9).
- Prior uterine surgery: Any previous surgery, such as cesarean section or uterine fibroids removal surgery, may increase your risk of placental conditions (10).
- Blood pressure: High blood pressure or hypertension levels might affect your placental function (11).
- Substance abuse: If you smoke or take drugs, you may be at risk of placental conditions (12).
Some of the possible problems related to the placenta include:
- Placental abruption: It is a condition in which the placenta separates from the uterine wall before delivery. It could deprive the fetus of oxygen and nutrients and may result in premature birth, stillbirth, and growth problems; it can cause severe bleeding (13). One-third of the cases of abruption are associated with any form of hypertension.
- Placenta previa: It occurs when the placenta lies low in the lower uterine segment of uterus and covers the opening of the cervix partially or totally. It may, therefore, block the baby’s exit from the womb, resulting in preterm labor, placental tear, and antepartum and intrapartum hemorrhage (14) (15).
- Placenta accreta: This rare complication occurs when the placenta grows into the uterine wall and is unable to be detached properly during delivery. It could lead to vaginal bleeding during and after delivery (16).
- Retained placenta: A part of the placenta or membranes remain intact in the womb after childbirth. It may occur when the placenta gets stuck behind a uterine muscle. It could be a life-threatening condition and requires manual removal of placenta (MROP) after a few hours of delivery (17).
- Placental insufficiency: The placenta may not be able to transfer nutrients to the fetus. It may lead to fetal growth restriction (FGR), stillbirth, and low birth weight (18).
- Anterior placenta: The placenta develops on the front of the uterus with the fetus behind it. It could make it difficult for you to feel the fetal kicks and for sonographers to find the heartbeat. It may lead to placental abruption, intrauterine growth restriction, and fetal death (19).
What Are The Signs And Symptoms Of Placental Problems?
The signs and symptoms that may indicate placental problems include:
- Vaginal bleeding
- Back pain
- Abdominal pain
- Constant uterine contractions
- Decreased fetal movement
You should see your doctor if you begin to experience these symptoms suddenly and often.
Can You Reduce The Risk Of Placental Problems?
You might not be able to prevent several of the placental problems. But you may take a few measures for a healthy pregnancy.
- Go for regular prenatal checkups.
- Manage health conditions such as blood pressure and gestational diabetes.
- Quit smoking and use of illegal drugs.
- Inform your doctor if you had any placental problem in your previous pregnancy or had any surgery of the uterus.
How Is The Placenta Delivered?
Usually there are mild contractions (sometimes there may not) that could help the placenta to separate from the uterine wall and move through the birth canal.
In a vaginal delivery, the third stage of labor begins with childbirth and ends with placental delivery. Your practitioner may inject Pitocin (oxytocin) into your body to induce uterine contraction and speed up placenta expulsion (20).
In a C-section, your practitioner physically removes the placenta before closing the incision. The remaining fragments are removed to prevent infection and bleeding (21).
Does A Doctor Check For Placental Abnormalities Even Without Symptoms?
During the regular ultrasound scans, the healthcare practitioner checks for all possible placental abnormalities. Placental conditions are likely to be associated with vaginal bleeding, and it is important to seek medical attention.
Frequently Asked Questions
1. When does the placenta fully form?
The placenta fully forms by weeks 18 to 20 and continues to grow throughout the pregnancy. It is likely to weigh around one pound at the time of delivery (22).
2. Is the placenta part of the baby or the mother?
The placenta is a fetomaternal organ comprising two parts—the fetal placenta that develops from the same blastocyst, which forms the fetus (villous chorion), and the maternal placenta that develops from the tissue of the maternal uterus (decidua basalis) (23).
3. Which placenta position is best for normal delivery?
The placental position may not be a cause of concern in several cases. The anterior placenta position—the placenta in front of the stomach—could make it difficult to hear the fetal heart sounds.
The placenta supports a baby’s life inside the womb. It offers the baby nourishment and performs all the necessary functions that a baby can’t do itself. Hence, ensuring proper placental functioning is essential for the viability of the pregnancy. Going for prenatal checkups regularly and quitting smoking, alcohol, and illegal drugs are a few ways to prevent some of the placental problems. Keep your doctor informed about any placental or uterine problems so they can guide you better.
Infographic: What Are The Risks Of Pills Made From Your Own Placenta?
Placenta pills are capsules containing dried and powdered placenta collected after delivery. Some women may consume it believing it’s beneficial as the placenta nourishes the baby during pregnancy. However, it may cause harmful effects, and the benefits are not scientifically proven. Read through the infographic to know the risks of consuming placenta pills postpartum.
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20. Cesarean Delivery; Stanford Children’s Health
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