First, thank you all, all the people who "derlurked." I've saved the blog addresses of those who were not on already my reading list, and I look forward to reading your stories.
Apparently, there is an ultrasound every month from this point on. I was pretty darned happy to hear this, and I went back to Mediscan, where I've had all ultrasounds done so far. This is a lab chain that specializes in fetal testing, and the doctor here is one that I absolutely have come to like and respect. Her name is Vandana Bhansal, and I highly recommend this place (and her) for antenatal testing.
The ultrasound was going well. Dr. Bhansal then casually asked J what her blood type was. Both my mother and I were shocked out of our wits when she replied "B negative." Negative?!?! That means she does not express the Rh antigen. I do express it, as does my donor.
Rh- moms need specialized attention when they are carrying an Rh+ baby, because if there is is mixing of fetal and maternal blood, the mother will make antibodies against the fetal Rh antigen. Those antibodies can then cross the placenta and can cause fetal anemia and jaundice. Severe anemia can even result in fetal demise. If the mother is sensitized to the Rh antigen in one pregnancy, then all the later pregnancies are at risk. To prevent this, the mother should be given the Rhogam shot at 2 points: at 28 weeks of pregnancy when the chance of fetal blood mixing is 1%, and at delivery, when it goes up to 10%. If an Rh- mother has a miscarriage or trauma during pregnancy, the Rhogam shot is administered at that point as well.
Now, Rh negativity is sort of rare. It is high in the native American population, and rare amongst Caucasians. I thought it was rare amongst Indians as as well...I found out that it was more common than I thought, coming in at about 10%.
I never dreamed that a Rh- surrogate would be selected, especially given the masses of women available for surrogacy in this country that are Rh+. I never got the surrogates initial screening tests (I had to literally badger my RE for the initial thyroid testing results); had I seen this, I would have gone with somebody else. I'm shocked that I had to find out by accident, and I am so grateful that I got Dr. Bhansal; had I not, this may have never come to light, and I'm not sure if my RE told the OB specifically about this, or was aware of it.
So here I am, having to live with this wrinkle as well. We immediately had her tested...as of now, she does not have antibodies against the Rh antigen; she has received one of the two mandated injections (the one given at the time of birth) following all her pregnancies. Not being the sort to take chances, we will have to administer the Rhogam shot during pregnancy as well. Now, Rhogam used to contain thimerosol (ethyl mercury) as a preservative. It was recently removed in the version administered in the US, but I don't know whether the older version is still in use in India. I'm stuck with the headache of ensuring that a thimerosal-free version is given.
All was well in the ultrasound too: the thing that made me slightly worried is that the head circumference growth is lagging--it went from above the 50th percentile at 19 weeks to the 12th percentile at 25 weeks. The one thing that is absolutely ahead is femur length, coming in at the 84th percentile.
I'm trying not to think about microcephaly, and I'm trying to remind myself that I have an absolutely tiny skull as well, and was apparently incredibly low birth weight (under 4 pounds at 41 weeks!!), and I turned out to be perfectly healthy. This baby is sort of like how I've been all my life---small head, long legs, so worrying is stupid,right?