Amniotic fluid, whether abundant or scarce, impacts the fetus. Therefore, expectant mothers should not be careless. But what exactly are these effects? Many mothers may not fully understand. Today, we'll explain the functions of amniotic fluid and how its quantity affects the fetus.
Functions of Amniotic Fluid
Protecting the Fetus.The fetus moves freely within the amniotic fluid, preventing adhesions that could cause fetal deformities. It maintains a constant temperature and pressure within the uterine cavity, reducing injuries to the fetus from external forces.
Protecting the Mother. Amniotic fluid alleviates discomfort for the mother caused by fetal movements. During labor, the amniotic sac uses the fluid's pressure to dilate the cervix, preventing prolonged direct pressure from the fetus on the mother's tissues and reducing the risk of cervical and vaginal damage.
Facilitates various examinations to determine fetal gender, maturity, and presence of genetic disorders.
Lubricates the birth canal to aid delivery. When the amniotic sac ruptures before labor, amniotic fluid flows into the vagina like an advance guard and lubricant, making the birth canal wet and slippery to facilitate smooth fetal passage.
Amniotic fluid serves multiple functions, and its volume is critically important.
Effects of Amniotic Fluid Volume on the Fetus
Polyhydramnios (Excessive Amniotic Fluid)
An Amniotic Fluid Index (AFI) greater than 25 cm indicates "polyhydramnios." Common causes include multiple pregnancies, fetal abnormalities (e.g., hydrocephalus),gastrointestinal obstruction, gestational diabetes, and unexplained causes. When amniotic fluid exceeds a certain threshold, it can enlarge the pregnant uterus, leading to uterine distension, premature contractions, and preterm labor. It may even cause amniotic membrane rupture and amniotic fluid leakage.Amniocentesis To prevent preterm labor caused by polyhydramnios, obstetricians may drain excess amniotic fluid—a procedure known as "amniocentesis." This reduces uterine strain, thereby lowering the risk of premature birth.
Oligohydramnios
An AFI measurement below 5 cm indicates "oligohydramnios." The most common cause is premature rupture of membranes (PROM), followed by fetal renal dysfunction, anuria, or placental insufficiency. Reduced amniotic fluid volume can lead to uterine atony, fetal growth restriction, placental abruption, limb deformities, and impaired lung development.
Adequate amniotic fluid volume is crucial for ensuring healthy fetal development.