Rh sensitization and ABO incompatibility

What is a newer innovation for hyperbilirubinemia management that is wrapped around the baby

A newer innovation for hyperbilirubinemia management is the phototherapy blanket, a fiberoptic blanket that is wrapped around the baby. Light generated by the blanket has the same effect on bilirubin levels as banks of overhead lights.The advantages of a blanket are that an infant can be held for long periods without interrupting the phototherapy, and eye patches are unnecessary (Box 26.12).

when might an infant need an exchange transfusion and what for?

After birth, the infant may require an exchange transfusion to remove hemolyzed red blood cells and replace them with healthy blood cells (see Chapter 26). A woman needs to discuss her plans for further childbearing and should be pro-vided with contraceptive information if she believes the strain of this pregnancy, the constant feeling of wishing that everything was all right but never being certain that it was, is more than she wants to endure again.

Give an example (situation) of Rh incompatibility with father/mother

For such a situation to occur, the father of the child must either be homozygous (DD) or Dd genotype). For such a situation to occur, the father of the child must either be homozygous (DD) or heterozygous (Dd) Rh-positive. If the father of the child is homozygous (DD) for the factor, 100% of the couple's children will be Rh-positive (Dd). If the father is heterozygous for the trait, 50% of their children can be expected to be Rh-positive (Dd). Although this is basically a problem that affects the fetus, it causes such concern and apprehension in a woman during pregnancy that it becomes a maternal problem as well.

what are the steps in the procedure for blood transfusion?

From 75 to 150 mL of washed red cells are used, depending on the age of the fetus. After deposition of the blood in the cord or abdomen, the cannula is withdrawn and a woman is urged to rest for approximately 30 minutes while fetal heart sounds and uterine activity are monitored.

i don't completely understand this

Hemolysis can become a problem with a first pregnancy in which there is an ABO incompatibility as the antibodies to A and B cell types are naturally occurring antibodies or are present from birth in individuals whose red cells lack these antigens.

When do hemolysis begin

Hemolysis of the blood begins with birth, when blood and antibodies are exchanged during the mixing of maternal and fetal blood as the placenta is loosened; destruction of red cells may continue for up to 2 weeks of age.

What is an advantage of home phototherapy

Home Phototherapy. Home phototherapy is primarily used for decreasing physiologic jaundice rather than that associated with blood incompatibility. It has the advantage of allowing for uninterrupted contact between the parents and a newborn and therefore has the potential to aid bonding. Parents must understand the importance of the therapy; the lights must be a full 12 inches away from an infant to prevent burning; an infant must continuously wear eye patches and a diaper during phototherapy to protect the retinas and the ovaries or testes; and bilirubin levels should be assessed approximately every 12 hours.

why do preterm infants not seem to be affected by ABO incompatibility?

Interestingly, preterm infants do not seem to be affected by ABO incompatibility.This may be because the receptor sites for anti-A or anti-B antibodies do not appear on red cells until late in fetal life.

Why can these not cross through the placenta

These cannot cross the placenta and destroy fetal red blood cells b/c the antibodies are not the IgG class, the only type that crosses the placenta.

To restore fetal red blood cells, what can be per-formed on the fetus in utero.

blood transfusion

When a Rh-positive fetus begins to grow inside an Rh-negative mother who is sensitized what is her body reaction?

it is as though her body is being invaded by a foreign agent. Her body reacts in the same manner it would if the invading factor were a substance such as a virus; she forms antibodies against the invading substance.

define Hydrops fetalis

is an old term for the appearance of a severely involved infant at birth. Hydrops refers to the edema, and fetalis refers to the lethal state.

What antigen does people who have Rh-positive blood have that Rh-negative people do not?

they have a protein factor (the D antigen)

If the father is heterozygous for the trait, what percent of their children can be expected to be Rh-positive (Dd).

50%

during the birth of the first child there is an exchange of maternal blood from damaged villi. So most of maternal antibodies are formed when?

72 hours after birth. Most of the maternal antibodies formed against the Rh-positive blood are not formed during pregnancy but in the first 72 hours after birth, making them a threat to a second pregnancy.

When is the RhIG given agian to the mother

72 hr after birth. RhIG is given again by injection to the mother in the first 72 hrs after birth of an Rh-positive child to further prevent the woman from forming natural antibodies.

What is one thing we should urge parents to watch for with eye patches on infants during phottherapy

An infant should have the eye patches removed when away from the lights for feeding for a period of visual stimulation and interaction. The point at which infants are most apt to dislodge eye patches is when they cry as they wake for a feeding. Urge parents not to allow an infant under bilirubin lights to cry for a sustained period to avoid having this happen.

A reaction in an infant with type __ blood is often the most serious

B

Because RhIG is passive antibody protection what happen to the antibodies

Because RhIG is passive antibody protection, it is transient, and in 2 wks to 2 months, the passive antibodies are destroyed. Only those few antibodies that were formed during pregnancy are left. For this reason, every pregnancy is like a first pregnancy in terms of the number of antibodies present, ensuring a safe intrauterine environment for any future pregnancies.

calcium gluconate is given the exchange catheter after each ___mL of blood

During the transfusion, carefully monitor the newborn's heart rate, respirations, and blood pressure. Because blood stored for transfusion contains acid-citrate-dextrose (ACD), added to blood as an anticoagulant, which can lower blood calcium levels and cause acidosis, calcium gluconate is given through the exchange catheter after each 100 mL of blood. Ifcitrate-phosphate-dextrose was used as a preservative, hyper-glycemia may occur during the transfusion from the dextrosein the preservative. This may be followed by over production of insulin and hypoglycemia in the infant. If heparinized blood is used, the heparin content may interfere with clotting after the transfusion. In addition, because of its relatively low glucose concentration, heparinized blood may also lead to hypoglycemia. Administering protamine sulfate aids in the metabolism of heparin and restoration of clotting ability.

what does an elivated anti-D antibody titer of 1:16 or greater mean and what will happen

If a woman's anti-D antibody titer is elevated at a first assessment (1:16 or greater), showing Rh sensitization, the well-being of the fetus in the potentially toxic environment will be monitored q 2 wks (or more often) by Doppler velocity of the fetal middle cerebral artery, a technique that can predict when anemia is present or fetal red cells are being destroyed.

I don't completely understand this.....

If the artery velocity remains high, a fetus is not developing anemia and most likely is an Rh-negative fetus. If the reading is low, it means a fetus is in danger, and immediate birth will be carrie dout providing the fetus is near term. If not near term, efforts to reduce the number of antibodies in the woman or replace damaged red cells in the fetus are begun.

If the number of red cells has significantly decreased, the blood in the vascular circulation may be hypotonic to interstitial fluid; what will happen?

If the number of red cells has significantly decreased, the blood in the vascular circulation may be hypotonic to interstitial fluid; fluid will shift from the lower to higher isotonic pressure by the law of osmosis, causing extreme edema. Finally, the se-vere anemia can result in heart failure as the heart has to beat so fast to push the dilute blood forward.

In most instances of ABO incompatibility, the maternal blood type is __ and the fetal blood type is __

In most instances of ABO incompatibility, the maternal blood type is O and the fetal blood type is A; it may also occur when the fetus has type B or AB blood. .

what is the normal indirect bilirubin level

Normally, cord blood has an indirect bilirubin level of 0 to 3 mg/100 mL. An increasing indirect bilirubin level is dangerous because if the level rises above 20 mg/dL in a term infant or 12 mg/dL in a preterm infant, brain damage from bilirubin-induced neurologic dysfunction (BIND) ora wide spectrum of disorders caused by increasingly severe hyperbilirubinemia that range from mild dysfunction to kernicterus (invasion of bilirubin into brain cells) can occur. An infant needs to use glucose stores to maintain metabolism in the presence of anemia. This can cause a progressive hypoglycemia, compounding the initial problem. A decrease in hemoglobin during the first week of life to a level less than that of cord blood is a later indication of blood loss or hemolysis.

What are risks of blood transfusion procedure?

Obviously, intrauterine transfusion is not without risk. A cord blood vessel could be lacerated by the needle, or the uterus may be so irritated by the invasive procedure that labor contractions begin.

Why would parents need an explanation for phototherapy

Parents need an explanation of the rationale for phototherapy. Incubators are automatically associated with seriously ill infants, but the use of lights does not seem scientific (almost a home remedy). Parents can easily be confused by the two interventions, one seemingly serious and the other seemingly not serious at all. Although the long term effects have not yet been studied, there appears to be minimal risk to an infant from phototherapy, provided the infant's eyes remain covered and dehydration from increased insensitive water loss does not occur. It is too early to predict if all infants who receive phototherapy need follow-up in coming years to detect skin cancer that possibly could occur from the therapy (Newman &Maisels, 2007).

What does phototherapy do for infants liver

Phototherapy. An infant's liver processes little bilirubin in utero because the mother's circulation does this for an in-fant. With birth, exposure to light apparently triggers the liver to assume this function. Additional light supplied by phototherapy appears to speed the conversion potential of the liver. In phototherapy, an infant is continuously exposed to specialized light such as quartz halogen, cool white daylight, or special blue fluorescent light. The lights are placed 12 to 30 inches above the newborn's bassinet or incubator. Specialized fiberoptic light systems incorporated into a fiberoptic blanket also have been developed and are ideal for home care. The infant is undressed except for a diaper so as much skin surface as possible is exposed to the light (Fig. 26.12).

To reduce the number of maternal Rh (D) antibodies being formed, Rh (D) immune globulin _____ is given

RhIG immune globulin. To reduce the number of maternal Rh (D) antibodies being formed, Rh (D) immune globulin RhIG , a commercial preparation of passive Rh (D) antibodies against the Rh factor, is administered to women who are Rh-negative at 28 wks of pregnancy.

When would a newborn scheduled for phototherapy therapy

Term newborns are generally scheduled for phototherapy when the total serum bilirubin level rises to 10 to 12 mg/dL at 24 hours of age; preterm infants may have treatment begun at levels lower than this (Symons & Mahoney, 2008).

what do the maternal antibodies do in the body?

The Rh factor exists a a portion of the RBC, so these maternal antibodies cross the placenta and cause RBC destruction (hemolysis) of fetal RBC. A fetus can become so deficient in RBC that sufficient oxygen transport to body cells cannot be maintaine. This condition is termed hemolytic disease of the newborn or erythroblastosis fetalis.

When does the mother receive an RhIG injection for a blood transfusion?

The mother receives an RhIG injection after the transfusion to help reduce increased sensitization from any blood that might have been exchanged.

What technique (procedure) is done for blood transfusion?

This is done by injecting redblood cells, by amniocentesis technique, directly into a vessel in the fetal cord or depositing them in the fetal abdomen where they migrate into the fetal circulation.

how often are transfusions done?

Transfusion is some-times done only once during pregnancy, or it may be repeated as often as every 2 weeks. As soon as fetal maturity is reached, as shown by a mature lecithin-sphingomyelin ratio, birth will be induced.

during which pregnancy is this effect small? The first or second?

first pregnancy

what is a normal and minimal titer range

normal=0, minimal= 1:8

define Rh incompatibility

occurs when an Rh-negative mother (one negative for a D antigen or one with a dd genotype) carries a fetus with an Rh-positive blood type (DD or Dd genotype).

give some examples of when fetal blood might enter maternal circulation

theoretically, there is no connection between fetal blood and maternal blood during pregnancy, so the mother should not be exposed to fetal blood. However, occasional villus ruptures, allowing a drop or two of fetal blood to enter the maternal circulation. Procedures such as amniocentesis or percutaneous umbilical blood sampling can also cause this.

How should you maintain the blood for exchange transfusion

Exchange Transfusion It also may be used if the serum bilirubin level is rising more than 0.5 mg/hr in infants with Rh incompatibility or 1.0 mg/hr in infants with ABO incompatibility. Keep a newborn warm during the procedure to prevent energy expenditure from having to maintain body temperature. Maintain the blood being given at room temperature, or shock from the cold insult can result. Use only commercial blood warmers to warm blood, not hot towels or a radiant heat warmer, to avoid destroying red cells.

What % of sensitized RBC are removed with exchange transfusion

Exchange Transfusion The therapy may be used for any condition that leads to hyperbilirubinemia or polycythemia. When used as therapy for blood incompatibility, it removes approximately 85% of sensitized red cells. It reduces the serum concentration of in-direct bilirubin and often prevents heart failure in infants. Because indirect bilirubin levels rise at relatively predictable levels, standards for performing exchange transfusion depend on the indirect bilirubin concentration, and transfusion is used when this level exceeds: •5 mg/100 mL at birth •10 mg/100 mL at age 8 hours •12 mg/100 mL at age 16 hours •15 mg/100 mL at 24 hours

What is the preferred method of treatment of neonatal jaundice

Exchange Transfusion. Intensive phototherapy in conjunction with hydration and close monitoring of serum bilirubin levels is the preferred method of treatment of neonatal jaundice. Despite these measures, if bilirubin levels continue to rise, exchange transfusion may be necessary. Before the procedure, the baby's stomach is aspirated to minimize the risk of aspiration from the manipulation involved. The umbilical vein is catheterized as the site for transfusion. The procedure involves alternatively withdrawing smallamounts (2-10 mL) of the infant's blood and then replacing it with equal amounts of donor blood. The blood is exchanged slowly this way to prevent alternating hypovolemia and hypervolemia. This can make an exchange transfusion a lengthy procedure of 1 to 3 hours. Automatic pumps are helpful to perform the exhausting repeated ritual. At the end of the procedure, using the last specimen of blood with drawn, hematocrit, bilirubin, electrolytes (especially calcium), glucose determination, and blood culture are taken. Exchange transfusion may need to be repeated because additional unconjugated bilirubin from tissue moves into the circulation after the exchange.

Rh sensitization is a complication for who...

complication of pregnancy, particularly i women who gave birth to a first child in an undeveloped nation where they did not receive passive anti-D antibodies. Any woman who does not receive a RhIG injection after an induced abortion, miscarriage, ectopic pregnancy, or amniocentesis can also have antibody formation begin.

If the father is homozygous for the factor (DD), how many of the couple's children will be Rh-positive (Dd)?

100%

at what week will the test be repeated of the first tier is minimal

28 wk. If the test is minimal it will be repeated at wk 28 of pregnancy. If this is also normal, no therpay is needed.

Define hemolytic disease of the newborn aka erythroblastosis fetalis

A condition that a fetus can become so deficient in RBBC that sufficient oxygen transport to body cells cannot be maintained.

I don't completely understand this....

After birth, the infant's blood type will be determine from a sample of the cord blood. If it is Rh-positive--Coombs' negative, indicating that a large number of antibodies are not present in the mother, the mother will receive the RhIG injection. If the newborns blood type is Rh-negative, no antibodies have been forme din the mothers circulation during and none will form, so passive antibody injection is unnecessary.

After the transfusion, closely observe the infant for what type of bleeding

After the transfusion, closely observe the infant for umbilical vessel bleeding. Redness or inflammation of the cord sug-gests infection. Report any changes in vital signs. Take and record a blood glucose determination at 1 hour after the pro-cedure. Monitor bilirubin levels for 2 or 3 days after the transfusion to ensure the level of bilirubin is not rising again and that no further transfusion is necessary. Erythropoietin may be administered to increase new blood cell growth and prevent extended anemia.

When can albumin be administered before the procedure (exchange transfusion)

Albumin may be administered 1 to 2 hours before the procedure to increase the number of bilirubin binding sites and to increase the efficiency of the transfusion. Be careful to monitor the rate of flow of the albumin transfusion, because rapid flow of such a viscous fluid can quickly overburden an infant's heart. The type of blood used for transfusion is O Rh-negative blood, even though an infant's blood type is positive; if Rh-positive or type A or B blood were given, the maternal antibodies that entered the infant's circulation would destroy this blood also, and the transfusion would be ineffective. An amount equal to twice the blood volume (average is 86 mL/kg) is used because this quantity will ensure an exchange of erythrocytes that is 85% to 90% effective. If the baby is transported to a regional center for the exchange transfusion, a sample of the mother's blood should accompany the infant, so cross-matching on the mother's serum can be done there.

Whan device can measure an infints bilirubin level

An infant's progress can be measured daily by a transcuta-neous bilirubinometer, a hand-held fiberoptic light placed against an infant's skin. The intensity of the yellow color of the skin is measured by the meter, and a numeric level of bilirubin is calculated.

Whys initiation of early feeding important for infants

Bilirubin is removed from the body by being incorporated into feces. Therefore, the sooner bowel elimination begins, the sooner bilirubin removal begins. Early feeding (either breast milk or formula), therefore, stimulates bowel peristalsis and accomplishes this.

What blood and blood type is used for fetus blood transfusion?

Blood used for transfusion in utero is either the fetus's own type (determined by percutaneous blood sampling) or group O negative if the fetal blood type is unknown.

What should a newborn's eye be covered with during phototherapy

Continuous exposure to bright lights this way may be harmful to a newborn's retina, so the infant's eyes must always be covered while under bilirubin lights. Eye dressings or cotton balls can be firmly secured in place by an infant mask. Check the dressings frequently to be certain they have not slipped or are causing corneal irritation. A constant concern is that suffocation from eye patches could occur.

When should infants eye patches be removed while receiving phototherapy

Infants receiving phototherapy should be removed from under the lights for feeding so that they continue to have interaction with their mother. In addition, supplemental feedings with additional formula may be recommended to prevent dehydration. Remove the eye patches while the infant is with the mother to give an infant a period of visual stimulation. To prevent a lengthy hospital stay, infants may be discharged and continue therapy at home.

What immediate measures should be taken to reduce indirect bilirubin levels

Initiation of early feeding, use of phototherapy, and exchange transfusion all may be immediate measures necessary to reduce indirect bilirubin levels in an infant affected by ABO or Rh incompatibility. In infants with severe hemolytic disease, the hemoglobin concentration may continue to drop during the first 6 months of life, or their bone marrow may fail to increase production of erythrocytes in response to continuing hemolysis. If this occurs, an infant may need an additional blood transfusion to correct this late anemia.Therapy with erythropoietin to stimulate red blood cell production is also possible.

when and why does jaundice occur in an infant

Most infants do not appear jaundiced at birth because the maternal circulation has evacuated the rising indirect bilirubin level. With birth, progressive jaundice, usually occurring within the first 24 hours of life, will begin, indicating in both Rh and ABO incompatibility that a hemolytic process is at work. The jaundice occurs because as red blood cells are destroyed, indirect bilirubin is released. Indirect bilirubin is fat soluble and cannot be excreted from the body. Under normal circumstances, the liver enzyme glucuronyl transferase con-verts indirect bilirubin to direct bilirubin. Direct bilirubin is water soluble and combines with bile for excretion from the body with feces. In preterm infants or those with extreme hemolysis, the liver cannot convert indirect to direct bilirubin,so jaundice becomes extreme.

What is the breakdown product of progesterone and how is it excreted

Pregnanediol, the breakdown product of progesterone,can interfere with the conjugation of indirect bilirubin. This is excreted in breast milk until the high levels of progesterone that were present during pregnancy are decreased, usually 24 to 48 hours after birth. Breastfed babies, therefore, may evidence more jaundice than bottle-fed babies.

how can Rh incompatibility of the newborn be predicted and confirmed?

Rh incompatibility of the newborn can be predicted by finding a rising anti-Rh titer or a rising level of antibodies (indirect Coombs' test) in a woman during pregnancy. It can be confirmed by detecting antibodies on the fetal erythrocytes in cord blood (positive direct Coombs' test) by percutaneous umbilical blood sampling (see Chapter 9) or at birth. The mother in this situation will always have Rh-negative blood(dd), and the baby will be Rh positive (DD or Dd).

What color is an infants stool and bilirubin lights and why is it that color

The stools of an infant under bilirubin lights are often bright green because of the excessive bilirubin that is excreted as the result of the therapy. They are also frequently loose and may be irritating to skin. Urine may be dark colored from urobilinogen formation. Monitor axillary temperature to prevent an infant from overheating under the bright lights. Assess skin turgor and intake and output to ensure that dehydration is not occurring from the warm environment.

What is the difference between an Rh-sensitized child and an ABO incompatibility

Unlike the antibodies formed against the Rh D factor, these antibodies are of the large (IgM) class and do not cross the placenta. An infant of an ABO incompatibility,therefore, is not born anemic, as is the Rh-sensitized child.

With Rh incompatibility, an infant may not appear pale at birth despite the red cell destruction that has occurred in utero. This is because ..........

With Rh incompatibility, an infant may not appear pale at birth despite the red cell destruction that has occurred in utero. This is because the accelerated production of red cells during the last few months in utero compensates to some degree for the destruction. The liver and spleen may be en-larged from an attempt to destroy damaged blood cells.

What titer should all women with Rh-negative blood have at a first pregnancy visit

anti-D antibody titer