Human red blood cells (to put it simply, redblood cells) have various antigens on their surfaces. They define a group or Rh affiliation owner. A group of such antigens determine the Rh blood positive (Rh +) 85% of people on the planet, and negative in the remaining 15% (Rh-), all the horrors and fears related to the fact that the future mother revealed a negative Rh factor, basically often hypertrophied. With proper regard to their own health it is quite possible to avoid many troubles.
The percentage of Rh-positive andRh-negative people in any country depends on the race of the population and geographical features of the area. So, there is no Rh-negative people, and if someone is determined Rh negative, then, was a white man among the ancestors among purebred blacks and Chinese. It is also curious that the more a country located north or locality, the more her Rh-negative inmates, and vice versa.
The basis of the conflict
Rhesus factor of fetus appears already in 7-8 weekspregnancy, that is, at a delay of menstruation for 3-4 weeks. If the expectant mom Rh-negative and the daddy - Rh positive, there is a chance that a child will inherit from the father Rh positive. Protective power of the maternal organism recognize rhesus fetus as something alien to him and produce zaitnye proteins (antibodies). They cross the placenta and destroy the erythrocytes crumbs, causing him hemolytic disease. Generation of antibodies occurs after direct contact of blood of mother and fetus.
If both parents are Rh-negative,Pregnancy always runs safely, as the baby will also be Rh-negative. More often than not in the normal course of the first pregnancy, Rh-conflict does not arise. However, at times during labor, as well as placental abruption, during during pregnancy such manipulation as a genetic amniocentesis (sampling of amniotic fluid from the amniotic sac), or cordocentesis (blood from the umbilical vein sampling) may be cast fetal blood in the mother's bloodstream, in bringing develop antibodies to the Rh.
If a woman has already had childbirth or abortion,miscarriage, ectopic pregnancy in the period more than 7-8 weeks, it is likely that the Rh-conflict (the probability of such a conflict is not more than 10%) may occur during the next pregnancy.
Methods of diagnosis
There are diagnostic methods to help your doctor beforebirth to navigate, which the fetus Rh Rh-negative mom and whether there is a conflict, and in case of hemolytic disease - to assess its severity.
The titer (number) antibodies to Rh in the mother's blood -Fasting from a vein moms bled and look to see if there Rh antibodies, and if so, in what amount. If serum antibodies detected or not detected in small credits, then the study is repeated over time: 1 every 4 weeks to 20 weeks of gestation, on indications then - 1 every 2-4 weeks until delivery.
If the antibody titer of questionable or high, thenAmniocentesis is performed - sampling of amniotic fluid from the amniotic sac under the control of ultrasound. Determine the optical density of the water, the titer of antibodies to the Rh, and fetal blood group. With a high optical density of amniotic fluid, which indicates the decay of red blood cells of the fetus, decide how to continue to maintain a pregnancy.
Cordocentesis - taking blood from a vein of the umbilical cord atcontrol of the ultrasonic probe. Determine blood group and Rh factor of the fetus, the titer of antibodies to the Rh, bilirubin level, if there is fetal anemia (hemoglobin level). If after investigation it turns out that the fetus Rh-negative, like Mom, further dynamic observation is not necessary. Of the modern methods of diagnosis - definition of RhD (one of Rh antigens, the primary) in the blood of the fetus or mother's cervical mucus. If fetal RhD is not defined, then the fetus Rh-negative and further monitoring is not necessary.
The diagnosis also helps ultrasoundStudy: thickening of the placenta, polyhydramnios, as well as an increase in size of the spleen and fetal liver, accumulation of fluid in his stomach may be manifestations of the disease. Techniques such as amniocentesis and cordocentesis, themselves sometimes lead to higher antibody titers in maternal blood. Abroad, if the results of these procedures, it appears that the fetus Rh-positive mom introduced anti-Rhesus immunoglobulin (at a lower dose than after childbirth)
If the mother diagnosed with high antibody titers to the rhesus
If the mother diagnosed with high antibody titers to the rhesus, high optical density of amniotic fluid, there are ultrasound signs of hemolytic disease of the fetus, is being treated.
- Intravenously infused vitamins, glucose solution.
- Administered intravenously human immunoglobulin every 4 weeks until delivery. This helps to reduce the titer of antibodies to the Rh.
- Spend plasmapheresis. The method consists in the mother blood drawing in the amount of 250-300 ml, then formed elements (red and white blood cells) back into the bloodstream, and the withdrawn liquid portion (plasma) of blood is replaced with other medical solutions (albumin, etc. rheopolyglucin ).. Thus, it carried out as if the mechanical purification of the mother's blood antibodies to Rh contained in the plasma. This treatment is applied to the second half of pregnancy.
- Hemosorption - removal from the blood of toxicmaterials using a special apparatus in which blood is passed through the filters. In this case, the mother's blood is cleansed of anti-Rh, then she returned back into the bloodstream.
- Intrauterine transfusion of Rh-negative blood odnogruppnoy fetus from 18 weeks of pregnancy.
There are two ways of blood transfusion.
- Blood under the control of ultrasound is introduced into the stomach of the fetus, where it is absorbed into the bloodstream.
- Intravascular transfusion - also performedunder the control of ultrasound: a puncture through the anterior abdominal wall, the wall of the uterus long needle into a vein of the umbilical cord and enter the Rh negative blood, taking into account the blood group of the fetus.
The administered Rh-negative blood is not destroyed by the antibodies the mother, in contrast to their own fetal blood.
Prevention of hemolytic disease
It is impossible to carry out a blood transfusion excludingRhesus affiliation of the donor and the patient. If a woman is Rh negative, it can be poured only Rh-negative blood, if it is Rh positive - only Rh-positive.
Women with negative Rhesus need a reliable method of contraception. For any termination of pregnancy can lead to the appearance of antibodies to Rh in the mother's blood.
After the termination of pregnancy on term of more than 7-8weeks just need to enter the anti-Rhesus immunoglobulin containing antibodies to Rh, which bind the Rh antigen fetus and prevent the formation of their own antibodies to it in the mother.
If during pregnancy the Rh negativeMommy performed amniocentesis or cordocentesis, after the need to enter antirezus - immunoglobulin at a dose of 100 micrograms. In Russia, such a preventive maintenance is not carried out.
After birth, the baby Rh-negative momdetermine the Rh factor. In the case of the birth of a Rhesus positive baby is introduced antirezus - immunoglobulin, if Mom is not yet sensitized (antibody titers in the blood are not high). Immunoglobulin is introduced not later than 72 hours after birth. Such prevention protects the fruit during subsequent pregnancies. After Caesarean section or manual removal of the placenta double dose of the drug.
Currently, in some countries over thewomen with Rh-negative blood, under normal titers of antibodies to Rh in 28-34 weeks of pregnancy are administered once or twice anti-Rhesus immunoglobulin, of course, if the father is Rh-positive.
Sometimes the situation is reversed - MomRh-positive, and a daughter - Rh-negative. During this pregnancy, Rhesus-conflict does not arise. However, childbirth girl can sensitized antigen mother. Because of this, my daughter since birth in the blood may be present antibodies to Rh. And when she becomes a mother, in the case of Rh-positive fetus can be Rh-conflict pregnancy.
How are we going to give birth
When an Rh-conflict recommendedhospitalization in the 34-35 weeks of gestation for examination and preparation for childbirth. Typically, labor is carried out in a natural way in the 37-38 weeks of pregnancy, but in severe forms of hemolytic disease of the fetus - prematurely, as le chit child outside the womb more easily than in utero. After the birth of crumbs engage neonatologists: conduct all the research and treatment aimed at eliminating anemia, jaundice, edema. If necessary, the baby is replacing blood transfusions and hemosorption.