Preface: Mothers-to-be know that the placenta has an important role in helping the baby absorb nutrients and metabolize waste, it is the energy bank for the material exchange between the fetal baby and the mother, and once the placenta has problems, the baby’s life will be greatly threatened. Therefore, mothers-to-be should know about the placenta, know the abnormalities of the placenta, and discover the abnormalities in time to ensure the safety of the baby and the mother-to-be. What is the placenta? The placenta is an accessory structure that connects the mother to the baby and is the source of life for the baby. It is attached to the uterus to obtain nutrients and oxygen, which are then supplied to the baby inside. If it is abnormal or aging, it directly affects the baby’s growth and development, and even endangers the baby’s life. What are the main functions of the placenta? 1.Metabolic function. Including gas exchange, nutrient supply and waste discharge. 2, defense function. It constructs a barrier between fetal blood and maternal blood to protect the fetus from the risk of infection. 3.Endocrine function. The placenta can synthesize a variety of hormones, enzymes and cytokines, which play an important role in maintaining normal pregnancy. For example, HCG (human chorionic gonadotropin), HPL (human placental lactogen), etc. 4. Immune function. The fetus and placenta are homografts that can survive in the maternal uterus without rejection because of their immunological properties (immune tolerance) related. Abnormalities related to the placenta in pregnancy I. Anterior placenta Normally, the placenta should be attached to the anterior, posterior and lateral walls of the uterus. However, in some cases, the placenta attaches like a small hat above the inner cervix, just above the head or buttocks of the fetus, a condition called placenta praevia. Red flags of placenta praevia: painless recurrent vaginal bleeding after the 7th month of pregnancy or bleeding without warning during labor and delivery without any aura or pain sensation. Causes of placenta praevia: There are three causes of placenta praevia. First, there is a lesion in the endometrium. For example, inflammation, scarring, or inflammation or injury of the endometrium caused by puerperal infection, multiple births, multiple scrapings, cesarean delivery, etc., which makes the metaplastic vessels of the uterus grow incompletely, and when the fertilized egg implants, the blood supply is insufficient and has to stretch to the lower part of the uterus, causing placenta praevia. Secondly, the placenta area is too large. Placenta previa can occur in multiple pregnancies or when the placenta extends to the lower part of the uterus. Third, delayed development of the trophoblastic lobe of the pregnant egg. After the egg enters the uterine cavity, it does not implant in the endometrium quickly and slips downward and implants near the uterine orifice, where it grows and develops to form placenta praevia. How can placenta praevia be prevented and detected? If a mother-to-be finds bleeding during pregnancy, she must go to the hospital promptly. Diagnosis by B-mode ultrasound is the most effective means to confirm the diagnosis. It will display the position and nature of the placenta and the condition of the fetus on the fluorescent screen at a glance to assist the doctor in timely diagnosis and treatment. The first is regular prenatal checkups to determine the location of the placenta through ultrasound; the second is to do as little scraping as possible to reduce endometrial trauma and minimize the occurrence of placenta praevia. Generally speaking, placenta praevia does not directly affect fetal development and does not necessarily threaten the life of the fetus. If the bleeding is mild, the pregnancy can continue as long as the bleeding is stopped, or the baby can be delivered safely from the vagina. If there is a lot of bleeding, the pregnancy has to be terminated in time, and a cesarean section can be performed while transfusing blood to save the mother and child from danger. II. Placenta abruptio The normal position of the placenta is close to the wall of the uterus before the baby is born. If the placenta is in a “mood” during this period and wants to detach from the uterine wall, it is called abruptio placenta. Both placenta abruptio and placenta praevia are the main causes of late pregnancy bleeding. The reason for placenta abruption: 1, gestational hypertension disease: most pregnant mothers should have heard of this gestational hypertension disease, but should not know that this disease is characterized by the spasm of small blood vessels throughout the body, which of course also includes the small blood vessels of the placenta, blood flow between the placenta and the uterus, it will make the placenta from the uterine wall to peel off. 2, trauma: this cause is understood by most pregnant mothers, the most common is the trauma caused by car accident trauma or fall, especially the abdomen directly impacted or fall when the abdomen directly touch the ground more dangerous. A fall while mopping the floor can trigger placental abruption. There is also a situation where the umbilical cord is too short and the fetal head drops and pulls the umbilical cord during delivery leading to placental abruption, which is also very dangerous. 3, twin pregnancy and excessive amniotic fluid: the common feature of these two cases is the high uterine tension. If the first fetus of a twin pregnancy is delivered too quickly or too much amniotic fluid flows out too quickly when the membranes are broken, the pressure in the uterus suddenly decreases and the uterus suddenly contracts, which can also lead to placental abruption from the uterine wall. 4, long-term supine position: we know that the lying position of the mother-to-be we usually recommend the left side of the lying position, late pregnancy or after delivery, if the pregnant mother for a long time to take the supine position, will occur supine hypotensive syndrome. At this time, because the mother’s huge uterus compresses the inferior vena cava, the amount of blood returned to the heart decreases and the blood pressure drops, while the uterine veins are stagnant and the venous pressure rises, causing stasis or rupture of the meconium vein bed, resulting in partial or total abruption of the placenta from the uterine wall. When a pregnant mother suffers from shock, fear, sadness, severe stimulation or other causes of mental overstimulation, it can cause circulatory disorders, peripheral vasoconstriction and dilatation of visceral vessels, including uterine vessels, and blood is transferred from the periphery to the viscera, causing them to become congested. The uterus is also congested and the sudden increase in blood can cause the blood vessels at the placenta to rupture and bleed, leading to placental abruption. Therefore, pregnant mothers must not be angry and fire, but must be good at controlling their emotions and always keep a happy mood. The danger signs of placental abruption: If there is sudden and severe pain in the abdomen, dark red blood flowing from the vagina, although the amount is not much, but the pregnant mother is pale, cold and sweating, breathing faster, and shock symptoms, you should send to the hospital as soon as possible. The reason is that although there is only a small amount of vaginal bleeding, a large amount of blood is actually being retained in the uterine cavity, which is also known as occult bleeding. This is also known as occult bleeding. The mother is already in circulatory collapse. In addition, the uterus will be enlarged, with spasmodic contractions, hard as a board, untouchable, and with significant pressure pain, indistinct fetal location and unknown heart sounds. What should I do in case of placental abruption? Once a dangerous situation occurs, in principle, we should race to get the fetus out. Only after the fetus is out and the placenta is expelled afterwards, the bleeding can be controlled and the uterus can contract quickly to stop the bleeding. If the placenta abrupts and the opening of the uterus has been opened wide, it is estimated that the baby can be delivered quickly within a short time, so it can be delivered vaginally after the membranes are broken manually under the close supervision of the doctor. Do not delay the delivery and delay the emergency. III. Abnormal placentation At conception, if the pregnant egg implants in the horn of the uterus, it may form a double placenta, a kidney-shaped placenta, a horseshoe-shaped placenta, or a deep sulcus on the placenta. If the lobulated chorion develops along the periphery of the pregnant egg, it forms a long, thin placenta, medically known as membranous placenta. A parietal placenta is formed when the implantation site of the pregnant egg is correct but there is an inflammatory lesion in the uterine mucosa at the implantation site. All these placentas with different morphology are abnormal placentas. It can easily remain in the uterine cavity during delivery and is one of the major causes of bleeding and infection during and after delivery. IV. In some cases, the placenta cannot be delivered for a long time after the fetus is born successfully. This is often due to inflammatory changes in the meconium or overgrowth of the lobulated chorionic villi, resulting in abnormal implantation of the placenta. If the chorion penetrates deeper into the basal layer of the meconium and the placenta adheres to the uterine wall, it is called an adherent placenta. If the chorionic villi penetrate deeper into the myometrium and the placenta adheres to the uterine wall, it is called implanted placenta. Both adherent placenta and implanted placenta can make placental abruption difficult and cause hemorrhage during labor. In the case of adherent placenta, the midwife needs to enter the uterine cavity by hand to peel it off; in the case of implanted placenta, it cannot be peeled off by hand either. If it is forced to peel off, bleeding and shock will occur, and the uterine muscle will be pierced, causing uterine perforation and infection, and the consequences will be very serious, at which time a caesarean section should be performed immediately to relieve the crisis. V. White placental infarction The white placental infarction is due to the lesion of the placenta, that is, there is white or yellow-white nodular degenerative tissue under the amniotic membrane of the fetal side of the placenta, which is harder. White placental infarcts, in some cases, can be as deep as the side of the placenta near the mother. If the degeneration is more and deeper, it can impair the function of the placenta so that the fetus dies in the uterine cavity, and it is prone to placental abruption. The placenta is attached to the uterine wall, connected to the fetus by the umbilical cord, and is the only energy reservoir for material exchange between the fetus and the mother. Through the placenta, the fetus receives nutrients and oxygen necessary for its development from the mother, and excretes metabolic waste through the placenta. Knowing the abnormal problems of the placenta, the mother-to-be should not worry too much when she encounters the same problem. If you find it in time and take appropriate measures, both the baby and you will be safe and sound.