Week 28: RhoGAM Shot

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This is your Pea in the Podcast for week 28 of your pregnancy. I'm Bonnie Petrie joined by Dr. Laurie Swaim, an obstetrician with Houston Women's Care Associates in Houston, Texas.

Well you're in the home stretch, the third trimester, and you might mark that milestone by having a shot. Don't get excited, it's a RhoGAM shot. "RhoGAM stands for RH immune globulin and it's given to women who have RH- type blood and if the father's blood type is unknown or if he is known to be RH+. The reason for this is that if the baby has RH+ blood and the mom is RH- her immune system will recognize those baby's blood cells as foreign because they have something on them that she doesn't have on hers and the baby's blood cells do escape into the maternal circulation. This RhoGAM is given to any woman in any stage of her pregnancy if she is bleeding or any procedures that could increase the chance of blood traversing the placenta, for example for amniocentesis CVS. If she has an ectopic pregnancy, she has a miscarriage, if she has a termination of pregnancy. She's also going to receive it probably if she has significant trauma to her abdomen. We give it at 28 weeks, it acts as what we call a blocking antibody, it goes around and scrounges up all the antibodies that mom has made to the baby's blood. Now why is this important? It's probably not that important for the first pregnancy, the first pregnancy will likely go well, and I think the risk for the second pregnancy if mom doesn't receive RhoGAM is actually still not that high, I think it's less than 10%. But the problem is what can happen is devastating. The mom's immune system will recognize the blood cells and say 'these aren't supposed to be here' and will chew them up like they're a virus or something. These antibodies cross the placenta and the baby ends up with horrible anemia and something called hydrops fetalis which is fatal if untreated." So if your blood type for example is O- or A-, one of the negatives, you need a shot in case your baby's blood type is positive. Dr. Swaim says you need it now. "It's given at 28 weeks because the most likely time where the blood is going to sort of cross over in the mom's circulation is late in the third trimester and we know that RhoGAM lasts for 12 weeks because of the way it was originally studied. At delivery, the baby's blood type is then determined and if the baby's blood type is RH- then mom doesn't need another Rhogam shot. But because at delivery there is a humongous exchange of blood from the baby to the mom, she is given a RhoGAM shot after delivery and sometimes it's actually calculated how much RhoGAM she needs based on how much blood is traversed into the mom's circulation after delivery. So that's that, that's RhoGAM in a nutshell. There's a test that we do before we give women RhoGAM called an Indirect Coombs and that's just to make sure she hasn't already developed some of these antibodies." RhoGAM has only been around since 1968 and thousands of babies died every year in the days before the shot. For you it's about as painful as any shot, they usually give it in the butt although it can be given in the arm; it's really no big deal.

So now that you're officially two thirds done with your pregnancy, "Okay you're going to start getting a lot more uncomfortable, baby starts to grow at a greater rate, you may have some swelling, and you're may be starting to get a little impatient." You also may be feeling a little emotional and maybe a little bit scared at this point. Some people are starting to feel frightened of delivery and others may be starting to feel nervous about what may happen after delivery because what are you supposed to do with the helpless person they're sending you home with, well it's totally normal, almost every woman wonders at some point during their pregnancy what in the world they've gotten themselves into. Talk to your doctor or midwife, they may be able to reassure you but I'm here to reassure you right now, you will be fine. Well you will be fine that is if you make it to the bathroom in time. You may now be struggling now with the need to pee about every other minute, the baby's taking up a lot of space in there and your bladder is suffering for it. This may cause a more embarrassing problem though, stress incontinence, which is a nice way of saying you may pee your pants a little every now and then. Particularly when you sneeze or something. You can minimize this problem by doing your kegels, kegel exercises help strengthen the muscles of the pelvic floor which will help you control the flow or urine and may help ease your delivery too.

Now what are these muscles and how do kegels work, you ask. Well the next time you pee, stop half way through; what muscle did you use to do that? Try it again. Those muscles, those are the muscles we're targeting. So squeeze those muscle in the same way throughout the day whenever you want. It's great because you can do these exercises any time and no one can tell. Some say if you continue doing them after delivery they will help you heal more quickly, others say if you do them during sex everybody's happy if what I mean. Yes, you know what I mean.

So anyway, let's talk about your baby. This week the little one's bone marrow is building all of its own red blood cells and their adrenal glands are producing hormones, androgen and estrogen. Now this is exciting because it's sending a signal which will stimulate your hormones to trigger milk production. They're also starting to chub up a little more in there, they have about 2% to 3% body fat and their muscle tone is increasing. They're now about 10 inches long and just over 2 pounds. You're 28 weeks pregnant with just 12 weeks to go now before week 40.

That's your Pea in the Podcast for week 28 of your pregnancy. Dr. Swaim and I look forward to talking to you again next week. Enjoy this week. For a transcript of any of our Pea in the Podcasts go to our website peainthepodcast.com. For Pea in the Podcast, I'm Bonnie Petrie, thanks for listening.