Okay, so alot of you may not know too much about the Rh factor.  I didn't either, until I discovered that I myself was Rh-negative.  Only fifteen percent of the world's population is in the same situation as I am.  My doctors never actually told me what this was

apart from that everything was alright, that I needn't worry, that any complications with my unborn could easily be circumvented with shots during my pregnancy and after the birth, blah di blah blah... placate placate.

Big.  Fat.  Hairy.  Deal.

I don't know about you but when I don't know the ins and outs of something that bothers me I will not rest until I know beyond the shadow of a doubt absolutely anything and everything there is to know about it.  Some call it obsessive-compulsive behaviour.  I prefer to think of it as peace of mind.

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So first of all, a quick synopsis on what the term actually means:

The Rhesus (Rh) factor, named after the Rhesus monkey, is a very important genetic component of human blood and can be found on chromosome 1.  This special protein or antigen (antibody-generating) coats the red blood cell for a purpose that is still as of yet unknown, but is not hazardous to your health due to its presence or absence.  Whether you're Rh-positive or Rh-negative is depicted as a plus or a minus symbol ( or -) after your blood group.  There are two Rh genes that are referred to: RhD and RhCE.  Technically there are three (C, D and E) but the other two are grouped together as they don't cause the problems that a lack of D can.

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I never would have discovered this fact had it not been for the blood tests I was undertaking early in my (at that time unknown) pregnancy.  My mother never knew of such a thing to exist, but I was jaundiced at birth.  She always put it down to my being overdue but I am now convinced that she is Rh-positive.  That would make my father the negative, as I have his blood type... which brings me to another important point.

It seems that the major concentration of Rh-negative people in the world is based upon ethnicity, being more prevalent in the European 'Basques', or a region of people residing over the west of Europe.  These include most of Spain, Portugal, and the southwest of France.  The Europeans alone hold a staggering 40-45% total of Rh-negative blood types worldwide.  My father is a Pacific Islander by birth, but our ancestry stems back to times of invasion and colonisation of New Zealand's islands by the... yep, you guessed it.  The Spaniards and the Portuguese.  Interesting stuff.  These days the Basque ancestry is all over the globe with established communities in the Americas, Canada, Australia and even southern Africa.

So, what does this mean for pregnancies?  Well, if you have a mother who is Rh-negative and a foetus that's Rh-positive, you have the possibilities for a lot of complications (some of which include jaundice, anaemia and failures of the heart and liver) and even the chance of miscarriage or stillbirth.  This is most commonly known as Haemolytic Disease of the Newborn, or HDN.  If the child's Rh-positive blood becomes present in the mother's bloodstream, her body will see this new antigen-rich blood as a 'foreign invader' and create antibodies to fight it off.  This can be especially detrimental through the second and subsequent pregnancies if the antibodies created from the first pregnancy cross the placenta and destroys blood cells of the unborn foetus.

Thankfully, there is the Anti-D injection which when administered within a 72-hour period of the placenta being received after birth, can destroy any remnant RhD cells in the mother's blood.  There are also routine Anti-D shots throughout the pregnancy at weeks 28 and 34 (and sometimes at term if baby is overdue), just in case of 'silent' placental bleeds.  If antibodies against the positive cells are allowed to form there is no way to destroy them, which can cause even more direct problems in a repeat pregnancy.  The antibodies at that time present alot more aggressively and directly. 

However, any real foetal damage can take weeks to manifest so regular check-ups are recommended if you're worried about your baby's condition.  If antibodies are detected a specialist monitors the foetus for anaemia and can give transfusions to the baby in utero.

So there you have it.  Due to advances in medical research, we have all of this information, answers and solutions for the lack of the RhD gene.  Furthermore, procedures can be carried out in order to guarantee you a healthy pregnancy and ensure the longevity, quality of life and wellbeing of the newest addition to your family.

For more information about the Rh factor in regards to pregnancy, see these sites:

Babycenter - http://www.babycenter.com.au/pregnancy/complications/whatisrhesusstatus

BellyBelly - http://www.bellybelly.com.au/articles/Pregnancy/rhesus-negative-pregnancy

Wikipedia - http://en.wikipedia.org/wiki/Rhesus_factor and http://en.wikipedia.org/wiki/European_Basque

Other information comes from loooots of different books that I've scoured over the last few months, but unfortunately I don't remember what they're called!  Sorry...