Anyone with experience in donating blood will know that in addition to blood types A, B, AB and O, there are also positive and negative points. Although negative blood type is not a disease and does not affect daily life, women with negative blood type should take special care during pregnancy to avoid fetal hemolytic anemia or even fetal death.
How does blood group indicate positive and negative? Li Runting, specialist in obstetrics and gynecology, said: ‘It refers to the presence or absence of rhesus monkey factor on red blood cells, i.e. Rh(D) factor. Rh(D) factor is an antigen on the surface of red blood. cells. If there’s an antigen, it’s blood positive, and if there’s no antigen, it’s blood group negative.” According to the Hong Kong Red Cross Society, only about 0.7% of Hong Kong’s population have negative blood type, which is very rare, also known as panda blood.
or produce anti-Rh(D) antibodies.
Pregnant women with negative blood type will not increase pregnancy complications, such as gestational hypertension or gestational diabetes, but since negative blood type is quite rare, in order to reduce the possibility of needing blood rounds during delivery , doctors generally advise pregnant women to absorb enough iron, prevent anemia; postpartum doctors will also inject drugs to strengthen uterine contraction.
When a woman with a negative blood type is pregnant, she must have blood drawn immediately to check her partner’s blood type. Li Runting explained, “If both parents have a negative blood type, the fetus will also have a negative blood type, so there is no need for a negative blood type mother during pregnancy. Matters that need attention. Whether the partner is blood positive, pregnant women with negative blood have the opportunity to conceive a fetus with positive blood.During pregnancy or delivery, fetal red blood cells containing positive blood can enter the mother’s blood circulation through the placenta, stimulating the body of the mother to produce antibodies against Rh(D).”
hemolytic anemia
In general, the first fetus is usually unaffected because more fetal red blood cells usually enter the mother at the time of delivery. But in the next pregnancy, the mother has already produced a large amount of anti-Rh(D) antibodies, which pass through the placenta and destroy the positive red blood cells of the fetus, causing hemolytic anemia, edema and even fetal death. Li Runting continued, “Once the body produces Rh(D) antibodies, they will exist permanently. Therefore, if Rh(D) antibodies are found in the early stages of pregnancy, we need to closely monitor the levels of antibodies in the blood of pregnant women, and also do regular ultrasounds to monitor the fetus for signs of anemia.”
prevent the production of antibodies
Since the blood type test can only be done after the baby is born to know whether it is a positive blood type or a negative blood type, in order to avoid the above problems, it is very important to prevent the mother’s body from to produce anti-Rh(D) antibodies. Li Runting pointed out, “When it is determined that the pregnant woman with negative blood group does not have Rh(D) antibodies in her body, she should be injected with Rh(D) immunoglobulin. The function is to destroy the Rh(D) (D) antigen from fetal red blood cells, so as to inhibit the mother’s immune system during pregnancy.Produce Rh(D) antibodies.Pregnant women should be screened for Rh(D) antibodies in early pregnancy and before 28 weeks, inject Rh(D) immunoglobulin at 28-30 weeks After the baby is born, it tests positive Pregnant women should be given Rh(D) immunoglobulin injection within 72 hours from delivery and if the baby is blood group negative, no other treatment is required.”
Originally released on AM730 https://www.am730.com.hk/Health/Negative Blood Pregnant Women-Attention to Fetal Hemolysis/348779?utm_source=yahoorss&utm_medium=referral
