Both parents are Rh negative. How is the Rh factor inherited in humans?

Rh factor (Rh factor) is a blood protein found on the surface of red blood cells. If this protein is present, then this means that the person has a positive Rh factor, but if it is not, then it is negative. Rh factor is determined by antigen. There are five main antigens, but the D antigen indicates Rh. 85% of the world's population have positive Rh factors. How to determine your Rh factor? It is enough just to donate blood from a vein once. This indicator does not change throughout life. In the embryo, Rh-affiliation is formed already in the first trimester of pregnancy. Determining this indicator is very important for a future mother, since in the case of an Rh-negative mother and a Rh-positive child, various pregnancy complications are possible. In this case, it will be especially important to follow the doctor's instructions, to avoid infectious and colds, as well as stress. Also on different sites there are so-called calculators that determine the Rh factor of the unborn child.

It must be remembered that blood is taken on an empty stomach. An express test for Rh affiliation can be taken at any independent laboratory where blood is taken (for example, Invitro). The price depends on the price list of the clinic itself. You can find out about the cost of the analysis immediately before delivery. You can also donate blood and find out your Rhesus for free if you become a donor. To do this, you need to fill out a form to register yourself as a blood donor in the appropriate institution.

Also, the Rh factor plays a big role in blood transfusion. Two people are involved in a transfusion: the recipient (the one who receives blood) and the donor (the one who donates blood). If the blood is incompatible, the recipient may experience complications after the transfusion.

The most common myth among couples is that the blood type (like the Rh factor) is inherited from a man. In fact, the inheritance of the Rh factor by a child is a rather complex and unpredictable process, and it cannot change during life. But it is worth remembering that in rare cases (about 1% of Europeans) a special type of Rh factor is determined - weakly positive. In this case, Rh is determined either positive or negative. This is where questions arise on the forums “why did my Rh minus change to plus?”, And also legends appear that this indicator may change. The sensitivity of the test method plays an important role here.

No less popular request on the network is "blood type horoscope". For example, in Japan, decoding by blood type is given great attention. Believe it or not - you decide.

In the world there is such a thing as a medical tattoo, photos of which can be easily found on the net. What do such tattoos mean and what are they for? Its designation is quite pragmatic - in case of a serious injury, when an urgent blood transfusion or operation is required, and the victim is not able to give the doctor data on his blood type and Rh. Moreover, such tattoos (a simple application of the blood type and Rh factor) should be in places accessible to the doctor - shoulders, chest, arms.

Rh factor and pregnancy

Rh factor compatibility during pregnancy- one of the tests that are carried out in the antenatal clinic. When a woman becomes registered with a gynecologist, she will need to donate blood to determine the group and Rh factor. It can significantly affect the course of the next nine months. If the baby inherits a positive father's Rh, and the mother's is negative, then the protein in the child's blood is unfamiliar to the mother's body. The mother's body "considers" the baby's blood as a foreign substance and begins to produce antibodies, attacking the baby's blood cells. With a Rh conflict during pregnancy, the fetus may experience anemia, jaundice, reticulocytosis, erythroblastosis, fetal dropsy and edematous syndrome of newborns (in the last two cases, the probability of death of the child is high).

Blood type and Rh factor: compatibility

The cause of incompatibility can be not only the Rh blood, but also the group.

What are the blood types? They are distinguished by the presence of specific proteins.

Four groups:

the first (most common) - O - there are no specific proteins in it;
the second - A - contains protein A;
the third - B - contains protein B;
the fourth (the rarest of all) - AB - contains both type A protein and type B protein.

First

on the protein of the second group (A);
on the protein of the third group (B);

Second(Rh negative) in a mother can provoke a conflict:

on the protein of the third group (B);
on the protein of the fourth group (B);
for the Rh protein (positive).

Third(Rh factor negative) in a mother can provoke a conflict:

on the protein of the second group (A);
on the protein of the fourth group (A);
for the Rh protein (positive).

Fourth does not conflict with any other group.
The only case when an immune reaction is possible: if the mother has the fourth group and is Rh negative, and the father is positive.

Table 1. Statistics

Blood types parents	Possible blood type of the child (probability, %)

Blood type and Rh - pregnancy without complications

The conflict does not arise if the spouses have Rh compatibility. In this case, the child has Rh compatibility with the mother's body: during pregnancy, the mother's body does not perceive the fetus as a foreign body.

Rh positive during pregnancy

If you are Rh positive, then a negative Rh husband will not affect the course of pregnancy. In the case when the child inherits the Rh factor is negative, there is no protein “unfamiliar” to the mother’s immune system in his blood, and a conflict will not arise.

Rh-positive mother + Rh-positive father = Rh-positive fetus
The child has inherited the positive Rh factor of the parents, and the pregnancy will pass without complications.
Rh positive mother + Rh positive father = Rh negative fetus
Even if the parent's Rh factor is positive, the baby can get negative. In this case, you can still talk about the compatibility of Rh factors during pregnancy: the mother's body is "familiar" with all the proteins in the child's blood.
Rh-positive mother + Rh-negative father = Rh-positive fetus
It is positive for the mother and the fetus, during pregnancy there is no conflict.
Rh positive mother + Rh negative father = Rh negative fetus
Although the mother and fetus have a different blood Rh factor (the mother and child have positive and negative, respectively), there is no conflict.

As already mentioned, blood Rh is a protein. And since this protein is already present in the mother's body, the blood of the fetus does not contain components that are unfamiliar to the mother's immune system.

Rh factor negative during pregnancy

Negative Rh during pregnancy is not always a sentence for the baby. The main thing is that it should be the same for both the baby and the mother.

Rh negative mother + Rh negative father = Rh negative fetus
The baby inherited the Rh factor of the parents. And since both the mother and the fetus have no protein (rhesus) in the blood and their blood is similar, then there is no conflict.
Rh negative mother + Rh positive father = Rh negative fetus
This is one of the cases when the Rh factor is very important: the compatibility of the blood of the mother and the fetus affects the next nine months of intrauterine life. Although the woman is Rh negative during pregnancy, it is good that the fetus is also Rh negative. There is no Rh in the mother's blood, nor in the blood of the fetus.

When does an Rh-conflict pregnancy occur?

Rh negative mother + Rh positive father = Rh positive fetus
Please note: whatever the mother's group, a negative Rh during pregnancy becomes a cause of conflict. In this case, the fetus inherits it from the father and brings the "new protein" into the body of the Rh-negative mother. Her blood "does not recognize" this substance: there is no such protein in the body. Accordingly, the body begins to defend itself and produce antibodies. They cross the placenta into the baby's blood and attack his red blood cells. The fetus tries to defend itself: the spleen and liver begin to work hard, while they increase significantly in size. If a child has few red blood cells, he develops anemia, or anemia.

What causes Rh conflict during pregnancy?

Rh-negative women should monitor their body very carefully and listen to its signals.
This attitude will help prevent:

dropsy (fetal edema);
anemia
miscarriage;
violations of the brain, speech or hearing of the child.

To protect the baby from these consequences, women with a negative Rh during pregnancy should take all the tests that the doctor prescribes on time.

What to do if you have an Rh-conflict pregnancy?

If your chosen one and you have Rh factors positive and negative, respectively, this must be taken into account when planning a pregnancy. Often, the Rh conflict does not appear during the first pregnancy, although the parents have a different Rh factor. Whatever the blood type of the future mother (Rhesus negative) during pregnancy, during the second birth, the likelihood of a conflict is very high, since her blood most likely already has antibodies.

Rh negative during pregnancy

There is a vaccine - anti-Rhesus immunoglobulin, which prevents Rh conflict during pregnancy. It binds the antibodies that the mother's body produces and brings them out. Vaccination can be done during pregnancy.

If you have a negative Rh, and your husband is positive, this is not a reason to refuse motherhood. Within 40 weeks, you will have to repeatedly donate blood from a vein:

up to 32 weeks - once a month;
from the 32nd to the 35th week - 2 times a month;
from the 35th to the 40th week - once a week.

If Rh antibodies appear in your blood, the doctor can detect the onset of the Rh conflict in time. In a conflict pregnancy, immediately after childbirth, a newborn is given a blood transfusion: the group, Rh factor should be the same as that of the mother. This is especially important in the first 36 hours of a baby's life - mother's antibodies that have entered the child's body are neutralized by "meeting" familiar blood.

When can immunoglobulin prophylaxis be carried out?

To prevent conflict in subsequent pregnancies, Rh-negative women should be prophylactic. This is done after:

childbirth (within three days);
abortion;
analysis of amniotic fluid;
spontaneous miscarriage;
ectopic pregnancy;
detachment of the placenta;
transfusions.

Remember: if your group and Rhesus are different with your baby, this is not an indicator that there will definitely be problems. Group and Rhesus are just the presence or absence of specific proteins in the blood. The reaction of the body and the development of pathologies in our time can be successfully controlled with the help of drugs. Your attention to your body, as well as an experienced doctor, will help you bear a healthy baby.

How do the chances of conception depend on the blood type?

Quite a lot is already known about the influence of blood groups, for example, on the likelihood of developing Alzheimer's disease, oncological diseases, blood clots, etc. However, virtually nothing was known about the effect on fertility. And finally, thanks to the efforts of Turkish doctors, a study appeared in this area.

A study published last week says that men with type 0 are four times less likely to develop impotence compared to guys with other blood types. Specialists from Ordu University in Turkey noted that blood type is as important a risk factor as smoking, being overweight, and high blood pressure. The reason is not clear, but scientists have said that in people with blood type A, the penis has a large number of veins, the lining of which can be damaged, which leads to erectile dysfunction.

Blood type also affects female fertility. Girls with the second group are more likely to bear a healthy child for a long time than with the first. Studies have shown that women with the first group quickly deplete their egg reserves early in life. But at the same time, women with type 0 have a lower risk of developing preeclampsia - high blood pressure during pregnancy, which can be dangerous for mother and child.

Naturally, representatives of the rest of humanity should not panic either (of which, by the way, there are a little more than half, because the people of the 1st group account for a little more than 40%) - a higher probability does not mean a 100% chance. As well as representatives of the "happy" group, you should not relax ahead of time - reduced risk does not mean zero at all.

Perhaps, in anticipation of the birth of a baby, the question of how the Rh factor is inherited is in the first place only among women who are afraid of a Rh conflict. For other parents, external data and the health of the unborn child are much more important. But it is worth noting that the characteristics of blood are no less important for a little man than hair color or eye shape, so you should familiarize yourself with the concept of Rh (Rh) and the principles of its inheritance.

Rh positive and negative

In humans, a group of lipoproteins can be on the surface of red blood cells, it occurs in about 85% of people, and in this case we are talking about the Rh-positive factor. But the absence of lipoproteins in 15% of children does not indicate a disease or developmental anomalies, but only indicates a negative Rh. The presence or absence of a lipoprotein group on an erythrocyte in most cases does not affect a person’s lifestyle in any way, only women with a negative Rh during pregnancy have a risk of an Rh conflict.

The lipoprotein formula has a rather complex composition, it will include various antigens, but the Latin D is used to denote the Rh factor:

"+" is denoted by D;
"-" put the letter d;

In this case, D is a dominant, and d is a recessive gene.

It would seem that D + d will always give a "+", but there are some nuances of the inheritance of the Rh factor, in which both Rh-positive parents give birth to Rh-negative children.

The mismatch of the Rh factor in parents and the child very often causes suspicions of treason and family quarrels, but in fact this is the norm and Rh-positive parents can give birth to Rh-negative children.

Why is this happening? To do this, we need to consider how parental genes are inherited and what a chromosome set is.

A little about genetics

Probably, many still remember from school that all cells of the human body, except for the cells of the reproductive system, consist of two chromosomes that carry dominant and recessive genes.

The egg and sperm have one chromosome set, and during fertilization, a new cell is formed that has a unique combination of chromosomes, which is responsible for external data and some features of the fetal body.

Rh, like other characteristics, is genetically transmitted, and the following combination may occur when the egg is fertilized:

As you can see, in the second case, the combination of Dd consists of a dominant and a recessive trait, that is, children are born with Rh "+", but they also have a recessive Rh "-" gene. Of course, at the level of genetic research, it is possible to identify which combination is available - DD or Dd, but this analysis is very complicated, it is not necessary.

For the presumptive determination of Rhesus by obstetricians, a table of inheritance is used.

Having considered how Rh is formed, it can be noted that a negative Rh in 100% of cases is inherited only from Rh-negative parents, in all other cases, the formation of both a negative and a positive Rh factor is possible. Moreover, the gender of the parent does not affect how Rh is inherited, inheritance depends only on the dominant gene.

A little about Rhesus conflict

Many women with Rh "-" are afraid to give birth to a man with Rh "+", fearing that they will not be able to bear and give birth to a healthy child. But this fear is not always justified.

Before dispelling most women's fears, it is worth considering how the Rhesus conflict proceeds:

the maternal organism, which does not have a lipoprotein component on the surface of erythrocytes, perceives the fetal lipoproteins as a foreign body;
the immune system of the pregnant woman begins to actively produce antibodies that destroy the erythrocytes of the embryo;
during this process, a large number of red blood cells die in the embryo, which leads to miscarriage or fading of pregnancy (fetal death).

The blood type and Rh of the fetus are formed by the end of the 3rd month of development, and it is at this time that a pregnant woman can lose her baby. But is there any hope for heterogeneous couples to have healthy children?

In fact, everything is not so scary and techniques have been developed that allow a woman to bear a full-fledged baby, even with a negative factor.

They include:

A specific vaccination that suppresses the reaction of the woman's immune system against foreign lipids. The vaccination can be done both before conception, when planning a pregnancy, and immediately after determining an interesting position.
Regular medical supervision. Such women have to take tests and visit antenatal clinics more often than other groups of pregnant women in order to timely identify the first deviations during pregnancy.

But only by the end of the 3rd month of gestation it will be possible to determine whether Rh “+” or Rh “-” is transmitted from the father. If a negative factor is detected in the fetus, then the pregnancy will proceed without the risk of embryo death due to the immune system of the pregnant woman.

Knowing about the inheritance of Rhesus helps to suggest the Rh factor of the baby even before his birth. But in most cases, this information plays an important role only in preventing Rh conflict in pregnant women.

AnnaMalia

06.08.2009, 18:27

Mom and Kiklan

06.08.2009, 18:35

From what I read, I realized that the negative ones have only negative ones.

06.08.2009, 19:18

No.
positives can have a negative child, but negatives cannot have a positive child

06.08.2009, 20:28

The child may have an incorrectly determined Rh, and the parents too.

06.08.2009, 21:55

if Rhesus has the same mechanism as the group, then it can. ask the geneticist

Mom and Kiklan

06.08.2009, 22:17

maybe, why not? why only in one direction, explain, pliz, or throw a link. Let's say with parents Rh + Rh +, and children rh- this very Rh, what was lost on the way?

Try a search engine, I just looked at the Rhesus inheritance table, there for negative ones - 100% negative is inherited.

06.08.2009, 22:30

found.
Patterns of inheritance of blood group and Rh factor.

Blood group inheritance is controlled by an autosomal gene. The locus of this gene is denoted by the letter I, and its three alleles by the letters A, B and 0. Alleles A and B are equally dominant, and allele 0 is recessive for both of them. There are four blood types. They correspond to the following genotypes:

First (I) 00

Second (II) AA; A0

Third (III) BB; B0

Fourth (IV) AB

Example 1:

The husband has a second blood group and is homozygous (AA)

Wife 00 + Husband AA

Gametes: 0 0 A A

Child: A0 A0 A0 A0

All children have a second blood group and are heterozygous for this trait.

Example 2:
wife has the first blood group (00)

The husband has a second blood group and is heterozygous (A0)

Wife 00 + Husband A0

Gametes: 0 0 A 0

Child: A0 A0 00 00

In this family, in 50% it is possible to have a child with the second blood group, and in 50% the birth of a child with the first blood group.

Rh factor inheritance
encoded by three pairs of genes and occurs regardless of the inheritance of the blood type. The most significant gene is denoted by the Latin letter D. It can be dominant - D, or recessive - d. The genotype of a Rh-positive person can be homozygous - DD, or heterozygous - Dd. The genotype of a Rh-negative person can be - dd.

Example 1:

Husband is Rh positive and heterozygous (Dd)

wife dd + husband dd

Gametes: d d D d

Child: Dd Dd dd dd

In this family, the probability of having an Rh-positive child is 50% and the probability of having an Rh-negative child is also 50%.

Example 2:
wife is Rh negative (dd)

Husband is Rh positive and homozygous for this trait (DD)

Wife dd + Husband DD

Gametes: d d D D

Child: Dd Dd Dd Dd

In this family, the probability of having a Rh-positive child is 100%.

I continue the topic.

gametes D d D d
children DD+, Dd+ , Dd+ and dd -

I do not claim the truth.

06.08.2009, 22:54

06.08.2009, 23:00

Maybe. I have an IV-, my husband has an I-.
Considered, that at children can only otrits. She gave birth to the second child at 1r / d (Rhesus-conflict) and there, at birth, all children are determined by the blood type. Imagine my surprise when it turned out that the child had II+. (I am sure of the paternity of my husband :)))
I asked the doctor why such a group turned out, maybe the analysis was mixed up?
I was told that this could be.
Now I want to know the blood group of the eldest son. Maybe not in the mother or in the father either :)
if your child was Rh-conflict, then he was positive. This has been confirmed. So my husband's rhesus is wrong.
"Conflict" children have only "negative" women.
Well, you know better about paternity.;):) Most likely, the Rhesus was incorrectly determined for the husband. Mei bi cross reaction...
well, we all solved the problems a page earlier.

AnnaMalia

06.08.2009, 23:16

She reassured her parents and sent everyone to retake blood.

Kirillova-mother

07.08.2009, 14:43

found.
[
I continue the topic.
examples not previously discussed.
3. wife with Rh positive heterozygote Dd and husband with positive heterozygote Dd
gametes D d D d
children DD+, Dd+ , Dd+ and dd -

4. well, dd and dd (both negative parents) cannot have either heterozygous Dd or homozygous DD positive children, only dd-, dd-, dd-, dd-. :(
because here the zygotes are only d d d d

5. Dd is positive. one parent + DD pos. other = all positive homo DD DD and hetero Dd Dd children

6. DD+ and DD+ positive parents = only homozygous positive DD DD DD DD children.

Maybe there are pitfalls?
I do not claim the truth.

When I was pregnant, my husband and I also read something like this. A daughter was born - a group like hers cannot be! (According to the table:).) The husband came to the doctors, stomped his feet - "you have incorrectly determined, redefine immediately!" He was driven away with the words "go, young man, everything is right, and this also happens."
Pys. This is OUR daughter. No options.

07.08.2009, 17:13

07.08.2009, 18:15

I'll tell you too. Zaberemenev, has gone on the analysis by definition gr. blood. I always knew that I had 1-, and in the certificate from the maternity hospital it is written (when I was born). According to the results of LCD: 1+. I had to retake it again in another place - the same thing. I called my mother: she, too, to which my mother screams in a tube: just don’t tell dad (there was no reason, but he is very suspicious - “first he beats, then he understands” :)). My mother donated blood, she also became a +, then my father was prepared and his blood was donated, he also turned out to be a +. So for 25 years my family went all "-", and during my pregnancy everyone became "+". I note that dad, in his youth, donated blood several times, there was always a "-", pr mum's ber. Same. No transfusions were done.

07.08.2009, 19:32

Well, it's simple!
Rh-negative parents can only have Rh-negative re.
Approximately 80% of the human population has a Rh antigen (conditionally called Rh-positive). But others do not. (Rh-negative) if neither mom nor dad has this antigen, where does it come from? all the stories when Rh-positive children are born to Rh-negative parents are most likely an error in determining the Rh of the parents or re.

07.08.2009, 22:32

About homo and heterozygotes, I think I know more than you.

:009:

Genetics is a science. This is not guesswork for you!

07.08.2009, 22:41

Well, what I know, only I know;)
and in categorical things it is not permissible to write IMHO, IMHO ... Well, you write book truths.
Okay, gone :020:

Dasha Petya

07.08.2009, 23:07

all the same, I’ll correct myself ... I wrote some nonsense at first.
There is a variant of a "weak" Rh factor, when laboratory errors are very likely. They can determine the "-" Rh, when in fact it is "weak", but "+". Then the probability of having a child with "+" is.

07.08.2009, 23:31

09.08.2009, 18:51

About homo and heterozygotes, I think I know more than you.
Rh antigen-dominant. if it is, then in any case, the Rh will be positive.
RhRh-homozygote. Rh-positive
Rhh-heterozygote. Rh-positive.
rhrh- and only in this case Rh-negative.
:009:
IMHO about the eyes and skin color: features such as hair, skin and eye color are not encoded by ONE GENE, but by a combination of several at once.
Genetics is a science. This is not guesswork for you.!}