Hi Marilyn and Andrea, Thanks for clarifying that point for me, it makes more sense now! I have to say though I am concerned by our government's willingness to throw these interventions around. Similar to the birth dose of Hep B, I really don't think there is true informed consent. I have had some clients go and have their partner's blood group and Hep B status checked, rather than administer something that may have some risk attached which may not necessarily be beneficial in their situation. Cheers, Nicole.
----- Original Message ----- From: "Marilyn Kleidon" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 27, 2004 10:49 AM Subject: Re: [ozmidwifery] Re: > Nicole: > > I think perhaps you are confusing giving anti-D prophylactically (usually > given once at 28weeks if antibody negative and then again postnatally if the > baby is Rh pos) with treating a possible sensitising event. > > When given prophylactically the "life" of the antibodies is thought to be > around 12 weeks, theoretically should a sensitising event occur in this time > period then these antibodies will take care of it. If the event were > significant then perhaps another dose would be given with appropriate blood > work (antibodies etc.. and FCAD). > > When treating a possibly sensitising event: when foetal blood cells would > mix with maternal ones eliciting and immuune response and hence a "memory" > in the mother's immune system which would make her sensitised then the time > period is 3 days or 72hrs. This time period is not the life of the > antibodies but the time interval within which the potentially sensitised > person will NOT from antibodies, hence if the anti-D is given within this > time period the anti-D will destroy the foetal blood cells before the > mother's immune system can respond and form a memory. Potentially > sensitising events include: spontaneous or intended abortion, placental > abruption, small unnoticed placental bleeds, threatened miscarriage with or > without observed bleeding, amniocentisis, ecv, birth, retained placenta, and > similar events. > > Once a mother has been sensitised then that is it in the sense that future > pregnancies will need to be monitored and antibody titres done to ensure > the well being of the baby in the interests of preventing HDN if possible. > > There are many issues around anti-D not the least being that it is a blood > product and thus a potential source of blood born contaminants/pathogens. I > do believe to date the actual processing needed to produce these antibodies > from sensitised donors has prevented the transmition of the blood born > pathogens. Nevertheless the potential remains and we would be fools to > ignore it, the scientific community certainly doesn't ignore it. > > Other issues have included the potential for these antibodies to cross the > placenta and start destroying the baby's blood cells themselves. If this has > happened I have not known it to be a significant issue: that is not the > source of significant hemolysis or anaemia in neonates possibly because the > supply is limited and not able to replicate itself. Another issue is the > possibility for the antibodies to sensitise an Rh negative baby, again I > don't think this has ever been recorded and to be honest doesn't make > immunological sense to me but that doesn't mean it couldn't happen (I am not > an immunologist). > > Anti-D has been given prophylactically in various communities around the > world since the late 1960's and has been extremely effective in preventing > HDN. As with all medications informed consent should be given. Have you > visited Sara Wickham's site at http://www.withwoman.co.uk/. > > marilyn > ----- Original Message ----- > From: "Nicole Carver" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Monday, October 25, 2004 2:40 AM > Subject: [ozmidwifery] Re: > > > > Hi Kristin, > > I have concerns about the reasoning behind the giving of anti D in > > pregnancy. It is apparently done because some women develop anti D > > antibodies without any obvious clinical events that can be treated with > anti > > D when they occur. (Previously anti D was only given if there was an event > > whereby foetal cells could enter the maternal circulation). I can't > > understand how giving anti D twice in pregnancy can prevent antibody > > formation for the whole pregnancy, when after birth, it must be given > within > > 72 hours to be effective. If the same period of action applies in > pregnancy, > > wouldn't it have to be given every three days throughout the pregnancy? > > Perhaps someone can set me straight on this? The other thing I am > concerned > > about is the wide scale use of a blood product on pregnant women. I feel > > certain that many women are not giving true informed consent to this. > > Kind regards, > > Nicole Carver. > > > > ----- Original Message ----- > > From: "Kristin Beckedahl" <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Monday, October 25, 2004 6:52 PM > > > > > > > > > > > > > Dear List, > > > > > > I have recently heard of the Anti-D that can be given during pregnancy > > > (28weeks?) for the prevention of HDN... does anyone know how effective > it > > > is, and if it is safe...? Thanks, Kristin > > > > > > > > > -- > > > This mailing list is sponsored by ACE Graphics. > > > Visit <http://www.acegraphics.com.au> to subscribe or unsubscribe. > > > > > > -- > > This mailing list is sponsored by ACE Graphics. > > Visit <http://www.acegraphics.com.au> to subscribe or unsubscribe. > > > -- > This mailing list is sponsored by ACE Graphics. > Visit <http://www.acegraphics.com.au> to subscribe or unsubscribe. > -- This mailing list is sponsored by ACE Graphics. Visit <http://www.acegraphics.com.au> to subscribe or unsubscribe.
