Rh Incompatibility
Rh, from the Rhesus monkey in which it was first identified, is a protein identifier for the D antigen in
red blood cells. When blood tests positive for that antigen, the result is a positive factor blood type (Rh positive, e.g. “O+”). If your blood tests negative, meaning the antigen is not present, it is a negative factor blood type (e.g. “O-”). Approximately
83-90 percent of the population is Rh positive.
Genetically, an Rh negative mom and Rh negative dad should conceive an Rh negative
child, and there is no risk involved. But an Rh negative mom and Rh positive dad can conceive either an Rh positive or Rh negative
baby. Mom’s and baby’s blood do not ordinarily mix in pregnancy unless there is uteroplacental trauma, however some transfusion
may occur with normal separation of the placenta at birth. If this happens there is a 7.5-13 percent risk that mom will become
permanently sensitized to a baby’s Rh positive blood, developing antibodies (known as isoimmunization) that would consider an Rh positive
baby to be a foreign body, destroying the baby’s red blood cells which can cause repeated miscarriage and/or a severe form of anemia
in the infant known as Hemolytic Disease of the Newborn (HDN), which can cause disabilities such as retardation and even death, or
may require blood transfusion in the newborn infant.
Treatment
A cord blood test can be administered immediately postpartum to
determine the baby’s Rh factor; if the baby turns out to be Rh negative, no further action is necessary. If the baby is Rh positive,
you may choose a postpartum injection of mercury-free Rho(D) immunoglobulin (tradename RhoGAM Ultrafiltered) to be administered
by a qualified person, which can lower the risk of being sensitized to 0.2 percent. RhoGAM is a blood-based prescription medication
that can effectively be injected up to 72 hours postpartum. The antibodies in the RhoGAM treatment attack any fetal blood cells that
are outside of the placenta. The foreign fetal cells are coated in the RhoGAM antibodies and expulsed from your system before your
body can detect them. The effects of immunoglobulin on the developing baby are controversial and not well studied; it can have
adverse fetal effects, including death.
If you are opposed to receiving RhoGAM, there are some things to consider:
v Avoid
invasive procedures which might cause bleeding accidents (e.g. amniocentesis, chorionic villus sampling, or aggressive external version).
v The chance of sensitization is greater in a cesarean.
v An excellent diet helps strengthen the placental
bed, minimizing the risk of premature separation.
v Citrus fruits and juices 3 times daily and a bioflavonoid/vitamin
C-complex tablet (1000 mg daily) help strengthen the placenta and membranes.
v Eliminate fluoridated
water and toothpaste, which interferes with the formation and distribution of collagen, the protein involved in placental attachment.
v 1 gm. powdered, activated charcoal daily
v 1 tsp. magnesium powder in water daily
v Kelp, sea vegetables, or mineral supplements daily.
v Fresh garlic or garlic oil capsules (10 capsules,
or 3 to 6 cloves daily).
v ½ c. elder flower infusion daily.
v If no sensitization
has been detected in pregnancy, delay cutting the cord to allow it to drain freely.
v Allow the placenta
to birth spontaneously, avoiding traumatic placental delivery.
Prevention
Prenatal administration of a low-dose Rho(D) immunoglobulin
(tradename Mic-RhoGAM) at 28-34 weeks with another postpartum injection can reduce the incidence of isoimmunization from 0.2 to 0.06
percent, however this minute lessening of the risk of antibodies should be weighed against the risk to your growing baby during pregnancy.
A blood test can be done at 28 weeks to determine the level of Rh antibodies in the blood (known as antibody titer) to decide
if a prenatal injection of Rho(D) immunoglobulin is merited. The level of titers at which it becomes necessary for hospital
birth varies, and the options should be discussed if there is a titer above 8.
Delayed cord clamping
In the past, it was customary
to clamp and cut the umbilical cord immediately after birth. Recent research indicates that mom is less likely to become sensitized
and baby is less likely to develop jaundice if clamping is delayed (or foregone completely) and the placenta is allowed to drain. Northeast Kansas Homebirth Service does not ordinarily clamp/cut the umbilical cord until after the placenta has delivered and stopped
pulsating. Delayed clamping also prevents blood from being pushed back into the maternal bloodstream while the placenta is still
attached, and gives the baby the full complement of blood that belongs to baby.
References:
Handbook of Maternal Newborn Nursing
by Buckley & Kulb, p385.
Varney’s Midwifery by Helen Varney, p357, 607.
Understanding Lab Work in the Childbearing Year, 4th ed.,
by Anne Frye, p79-95
Holistic Midwifery Volume I by Anne Frye, p77-95, 741, 914
Taber’s Medical Dictionary, p875, 1679-80
Birthkit, Summer
2004, #42 “Rhogam and Pregnancy: Stealth Mercury Assault,” Stephen C. Marini
“Don’t Clamp the Cord,” Dr. Sarah Buckley. http://www.lotusbirth.com/doc/FEB2003Lotusbirth-101.htm
Guide
to Effective Care in Pregnancy and Childbirth by Murray Enkin et al, 101-105.
Mayes Midwifery, Betty Sweet ed., p878
Active Management
of the Third Stage of Labour: Should the maternal end of the cord remain clamped? By Mia Tudor, 2000, p10.
http://www.legalrightsfyi.com/rhogam.html
