Negative ladies it may be a good idea to wait until you are past child bearing age to give plasma....read on:

Women's donated blood yields lifesaving RhoGAMPosted 2/8/2009 6:45 PM Jerome Davis  USA Today

Between them, Marilyn McCarthy and Elizabeth Pascoe may have saved tens of thousands of babies over the years.

They're not scientists or doctors or nurses (although McCarthy does work part time at the information desk of a hospital). They're moms helping other moms who, like them, belong to the small minority of people — 15% of whites, far fewer in other racial groups — with Rh-negative blood. Those folks have O-negative or A-negative or B-negative or AB-negative blood, as opposed to O-positive or A-positive or B-positive or AB-positive.

McCarthy, 72, and Pascoe, 68, don't want other pregnant women to go through what they did to build their families. So for 25 years and 30 years, respectively, the women have traveled twice a week from their Buffalo homes to a nearby lab to donate plasma, the key ingredient for a product called RhoGAM.

Injecting Rh-negative women with RhoGAM early in their third trimester and shortly after delivery prevents a potentially deadly condition called hemolytic disease of the newborn, or HDN. Maker Ortho-Clinical Diagnostics says about 700,000 syringes of RhoGAM are sold in the USA each year. Most Rh-negative women get two shots during pregnancy.

In the past few years, three similar products, Rhophylac, HyperRho and WinRho, also made from human plasma, have entered the U.S. market. But, Lockwood says, because RhoGAM has been around the longest, it remains the most widely prescribed.

A loss of four babies

Before RhoGAM's debut 40 years ago, nearly 10,000 U.S. babies died of HDN each year because their mothers were Rh-negative and they weren't. Four of those babies were McCarthy's.

McCarthy delivered her firstborn in 1956, her second in 1957. "Our first two were perfectly fine," McCarthy says. "Back then, we weren't aware of the problems with Rh. We just knew some babies had to be transfused after they were born."

But in 1959 and in 1961, after the drugs she had received in labor wore off, McCarthy awoke to hear her doctor tell her husband that their sons were stillborn, and a third son was stillborn in 1963. In 1965, her next child, a girl, survived after getting six blood transfusions while still in the womb and two more after birth.

McCarthy, who went on to adopt three children, delivered her last baby, a son, two months before his due date in 1969. He, too, had received a transfusion in the womb. His mother suspects that might have led to his prematurity and death within hours. That could well have been the case, says Ronald Burkman, an ob/gyn with Tufts University School of Medicine in Boston, who has received research support from Ortho-Diagnostics. Intrauterine transfusions are tricky, he says, and the fetal death rate was as high as 50% in the beginning.

People with Rh-negative blood don't have a certain protein, called the Rh factor, on the surface of their red blood cells. (Rh is short for rhesus, so named because scientists first identified the Rh factor in rhesus monkeys.)

For men, having Rh-negative blood is an issue only if they need a transfusion, because Rh-negative people can safely receive blood only from Rh-negative donors. (If you're Rh-positive, you can receive blood from either Rh-negative or Rh-positive donors.) But as McCarthy's experience illustrates, women with Rh-negative blood who don't receive RhoGAM face the risk of serious complications in their fetus.

Men with one functional Rh-factor gene are Rh-positive, and if the mother is Rh-negative, each of their offspring has a 50-50 chance of being Rh-positive. If the father has two functional copies of the Rh-factor gene and the mother is Rh-negative, all offspring will be Rh-positive.

If an Rh-negative mom's blood comes in contact with blood from an Rh-positive fetus — say, during amniocentesis (a procedure in which a needle withdraws a small amount of amniotic fluid, which contains fetal cells that are checked for chromosomal abnormalities) or delivery — her immune system would regard the Rh factor as a foreign enemy and launch an attack against red blood cells bearing it.

Often, women aren't exposed to fetal red blood cells until they deliver their first baby, which is usually unaffected. But once sensitized to the Rh factor, an Rh-negative woman will continue to produce antibodies against it. If she gets pregnant again, and her fetus again is Rh-positive, the attack will escalate, causing anemia, jaundice and possibly heart failure in the baby.

After her daughter's birth, McCarthy shared a hospital room with another Rh-negative mother, Pascoe, and, McCarthy says, "we've been friends ever since."

Pascoe's first pregnancy was uneventful, but with her second, blood tests sounded an alarm in the sixth month. "Your body is attacking your baby," her doctor said, warning that she could lose the child. Says Pascoe: "I can't tell you what that did to me."

Doctors induced labor a month before the baby was due. Twice in her first week, the baby's entire blood supply was replaced. Six weeks later, she received red blood cells. She did fine, but the doctor told her mom: "No more children for you for a while."

Four years later, with her doctor's OK, Pascoe was pregnant. Once again, tests at six months showed her baby was in trouble, and Pascoe was induced a month early. Not until they were born did Pascoe learn she had been carrying identical twin boys. One had his blood replaced twice after birth, the other once. Like their older sister, both received a "booster" of red blood cells. And like their sister, they came through it all fine.

Not long after her twins were born, Pascoe noticed a classified ad seeking Buffalo-area Rh-negative women to donate plasma for a research program. That was the beginning of her involvement with RhoGAM, and a few years later she recruited McCarthy.

Tricking the immune system

Apparently, RhoGAM contains enough Rh antibodies to trick the mother's immune system into not attacking her fetus's Rh-positive red blood cells. At first, plasma used to make RhoGAM came from women like McCarthy and Pascoe, whose blood contained Rh antibodies because they'd carried Rh-positive babies.

***This next paragraph is the one that concerns me:

But, thanks to RhoGAM, they're a vanishing breed, so most donors now are Rh-negative women and men who don't have Rh antibodies, says Joe Guetti, donor room supervisor at Somerset Laboratories, which collects plasma from about 300 donors. These Rh-antibody-free donors receive "mini-transfusions" of Rh-positive blood to incite their immune systems.

***A "mini-transfusion of positive blood into an Rh negative woman? Does anyone know how this will affect the woman or her children is she is having more? Has this been studied? I don't think so! In other words, in my opinion, any Rh negative woman that gets this "mini-transfusion" is being a guinea pig! I guess if you are a negative blood woman and ever consider doing this, wait until you're too old for it to matter much!

There's no way, however, to reproduce the personal connection that donors like McCarthy and Pascoe have. "I think we're all put on this Earth for a reason," Pascoe says, "and I think my reason is to give back."