Dear XXXXXX,
This is a rather complicated history, as you have already realized. I'm going to attempt analyzing it by writing my thoughts as they occur, involving you in my thought process, and then trying to solve this issue.
We have conflicting lab reports. So much of our management depends upon the accuracy of the lab. That's the problem. However, clinical judgment is also important.
A good dermatologist will be able to tell, by looking at the rash, what it could be. Rubella rash is described as scarletiniform rash which look like red or pink spots that merge to form evenly coloured patches. They first appear on the face, then body then the limbs. They resolve or disappear in 1-3 days.
Similar rashes appear in scarlet fever, some viral infections or even due to some drug allergies. Sometimes one may have to differentiate these from measles. Sometimes it could be just worms in the intestinal tract that cause rash!!
So to consult a good dermatologist AND a good physician would be important.

Rubella, once it occurs, imparts or gives immunity for life. Rubella infection can occur again but its usually milder. Generally we presume that once Rubella has occurred it won't occur again although, as i said, it MAY occur.
Therefore this on/off coming of rash generally indicates that its probably NOT Rubella.

Rash in Sep 2011, pregnancy in Feb and abortion in March 2012:
Any problem in Sep, Rubella or otherwise, CANNOT have been the cause of abortion at such a remote later date. 85% of women have a spontaneous abortion. So it could just be one of those things.

July 2012 IgM +ve: In my experience, most labs report IgM incorrectly and this one could be ignored. In your case, the rash had come in September 2011, more than 8 weeks earlier.

Whenever there is any viral infection, the body mounts a defense against it by producing anti-bodies (= immunoglobulins = Ig, in short). The first immunoglobulin produced is IgM, which peaks in 2-3 weeks after the infection, then falls to zero level by about 8 weeks. Just as IgM is peaking, the body produces the second antibody called IgG so that by the time IgM has become zero, the IgG has risen. IgG levels generally don't fall and in most viral infections like chickenpox, measles, rubella they last for a lifetime or at least at good protective levels for 10 years.

Now we come to the pregnancy with LMP 21.12.12:
By end of Feb 2013, your wife was 10 weeks pregnant when the rash appeared. Rash appeared again in 1st week march 2013. Very unusual behaviour and history for Rubella.
IgM was positive about 13 days after appearance of rash from a lab which may not be very reliable because at same time it was negative from a probably better lab.
IgM was positive in April too from a reputed lab. This was about 5 weeks from end of Feb when the rash first appeared. So it falls in the time period of the natural history of how IgM would behave, if this is Rubella.
IgG had not been done earlier and it was positive around the time IgM became negative. This too is according to how IgG would naturally behave if this is Rubella. Both the two labs however differ in the IgM reports.

One way to be sure is repeat IgG straight away, say this Monday morning. This testing would come about 2 weeks+ from last test on 4th April. There should be a 4 times increase in the IgG for a diagnosis of Rubella. If IgG does not show this kind of increase, then probably your wife does not have Rubella. If there is such an increase, i would recommend an abortion since chances of defects in baby due to Congenital Rubella Syndrome are as high as 90% in this case (since the first symptoms appeared at 10 weeks of pregnancy).

I wouldn't delay testing and decisions too much because abortion or termination of pregnancy beyond 20 weeks requires many permissions and is generally considered by everyone as illegal and your wife today is already 17 weeks and 3 days of pregnancy.
As i mentioned at the outset, do consult with a good dermatologist and a physician too. Discuss with your obstetrician the details of your case and follow her/his advice.
I hope i have been of help to clarify this complex situation.
My wishes for you.
Take care.
Dr Nirja Chawla

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Dear XXXXXX,
The stomach infection was just a hunch because worms can show any form of allergic response. Do talk to your specialist in medicine.

The first point for diagnosis would remain the IgM.
Since IgM is somewhat confusing, the second point for diagnosis would be 4-fold increase of IgG 20-30 days apart.
IgG Avidity >60% would indicate infection by Rubella 2-4 months earlier.
When data are equivocal, and to detect FETAL infection (vis-a-vis maternal infection), amniocentesis or fetal cord blood sampling (CBS) is the option.

It does make me a bit uncomfortable since IgM has shown positive in some tests. Although i do agree with the lab expert that modern technology picks up very low levels and yes, the value of IgM IS low. This IgM positivity may not be significant YET i cannot ignore it at this stage. Therefore further testing required.

All these tests are for diagnosis of infection in the mother. As i said earlier, if your IgG shows 4x increase OR, let me add clearly, even if it rises but is not 4x increase, meaning that again there is a dilemma, i would recommend the amniocentesis/CBS for finding if baby is infected.
Will await the IgG report.

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