Long placenta abdominal feeling

Everyone is generally familiar with the placenta. It is an important organ for exchanging substances between the fetus and the mother. During pregnancy, the endometrium in the mother's body will unite and grow into a binding device between mother and child. The fetus will develop in the uterus and needs to rely on the placenta for nutrients. During the growth of the placenta, the mother may experience abdominal pain, which is relatively normal.

Placenta structure

1. Amniotic membrane

The fetal part of the placenta is the innermost layer of the placenta. The amnion is a translucent membrane attached to the surface of the chorionic plate. The amniotic membrane is smooth, has no blood vessels, nerves or lymph, and has a certain degree of elasticity. The normal thickness of human amniotic membrane is 0.05mm.

2. Chorionic villi

The fetal part of the placenta makes up the majority of the placenta during pregnancy. When the embryo develops to 13 to 21 days, the villi gradually form. Around the third week after fertilization, when intravillous blood vessels form, fetoplacental circulation is established. The villi that are in contact with the basal decidua are called the chorionic villi. The ends of the villi suspended in the intervillous space filled with maternal blood are called free villi, and those that grow into the basal decidua are called fixed villi. The placental septum that grows from the decidual plate incompletely separates the fetal lobe into maternal lobes. Each maternal lobe contains several fetal lobes, and each maternal lobe has its own spiral artery to supply blood. The spiral arteries of the pregnant woman's uterus (also called the uteroplacental arteries) pass through the decidual plate into the maternal lobe. The substance exchange between mother and fetus takes place in the villi of the fetal lobule. The fetal blood goes through the umbilical artery to the villus capillaries, and exchanges substances with the maternal blood in the intervillous space. The two are not directly connected. The villous trophoblast of the full-term placenta is mainly composed of syncytiotrophoblasts, with cytotrophoblasts only scattered around. The inner layer of the trophoblast is the basement membrane, which serves as a placental barrier.

3. Decidua basalis

The maternal part of the placenta makes up a very small part of the placenta in full-term pregnancies. The maternal surface of the placenta is divided into about 20 maternal lobes visible to the naked eye.

Common placental abnormalities

1. Placenta previa

Normally, the placenta should be attached to the front, back and side walls of the uterus. But in some cases, the placenta is attached to the top of the internal cervix like a small hat, just sitting on the head or buttocks of the fetus. This situation is called placenta previa. According to the location of the placenta previa, it can be divided into three types: complete (or central) placenta previa; partial placenta previa; marginal (or low-lying) placenta previa.

2. Placental abruption

The placenta is normally located close to the uterine wall before the fetus is born. If it separates from the uterine wall during this period, it is called placental abruption. Placental abruption and placenta previa are both major causes of bleeding in late pregnancy. Once a dangerous situation occurs, in principle, the fetus should be delivered as quickly as possible. Only when the fetus is delivered can the uterus contract quickly and stop the bleeding.

3. Abnormal placenta

During conception, if the fertilized egg implants in the uterine cornu, a double placenta, a kidney-shaped placenta, a horseshoe-shaped placenta, or a deep groove may form on the placenta. If the chorionic villi develop around the fertilized egg, a long and thin placenta will be formed, which is medically called a membranous placenta. If the fertilized egg is implanted in the correct location but there are inflammatory lesions in the uterine mucosa at the implantation site, a secondary placenta will be formed. These placentas of various shapes can easily remain in the uterine cavity during delivery and are one of the important causes of intrapartum and postpartum bleeding and infection.

4. Placenta accreta and placenta accreta

Whether it is placenta accreta or placenta accreta, it can make placental separation difficult during delivery and cause heavy bleeding.

5. Placental white infarction

Placental white infarction is caused by placental lesions, that is, there is white or yellowish-white nodular degenerative tissue under the amniotic membrane on the fetal side of the placenta, which is relatively hard. If the degeneration is more severe and deeper, the placental function can be damaged, causing the fetus to die in the uterine cavity, and placental abruption is likely to occur.