Week 7: Prenatal Blood Testing

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

Welcome to week seven, your baby is about the size and shape of a Cheerio cut in half. The heart, that's been beating now for two weeks, is complete this week. The limb buds now look like little paddles as the trunk of your baby's body elongates and stretches, your baby's eyes look like dark spots and the lens is developing too. Permanent kidneys, the spleen and liver ducts are forming, the intestines are elongating. You can now see the cerebral cortex of the brain and you can clearly see the umbilical cord, that link between your baby and its placenta. Now your baby's also started to produce blood of its own type which maybe a different blood type from yours. Now if your blood is RH- that is if your blood type is A-, B-, AB- or O- and your baby's blood is RH+ that could be a problem. An RH- mother can make antibodies against RH+ blood cells, even against those of her own baby. Now those antibodies have the potential to cross the placenta and attack the fetus's red blood cells. It can cause your baby to have a low blood count which is anemia, congested heart failure and it can be fatal. Now this only happens if you become what is called sensitized to your baby's RH+ blood, doctors can generally prevent that with what is called the RhoGAM shot. The RhoGAM shot has been available since 1968 and if you're RH- you will get at least one during your pregnancy, right around 26 weeks. You'll also get one if you have an invasive test like an amniocenteses. Now many women don't know they're RH-. That's okay, when you go to your first prenatal appointment, your doctor will test your blood, in fact Dr. Laurie Swaim says you'll get tested for a lot of things with that first standard prenatal panel, "We get patient's blood type, we get a hemoglobin hematocrit which basically tells us whether they're anemic or not. Syphilis and hepatitis are state laws, we have to test for those. We can do HIV testing if the patients want it. The rubella titer: rubella in a sense has been eradicated in the United States partially because we've had such good immunization programs against it. Rubella is actually only really dangerous to adults when they are pregnant. The American College of OBGYNs suggests that we test gonorrhea and chlamydia in all patients. There's a test called an Indirect Coombs which basically looks to see in people's blood if they have antibodies in the blood. For women who are African American or of Mediterranean decedent we'll do a hemoglobin electrophoresis on them to make sure that they don't carry thalassemia or a sickle cell disease. Let's see what else do we get? In our practice we test the thyroid although I would say that there's really no firm recommendation for that. I'll tell you we do identify some women who are hypothyroid, very rarely hyperthyroid, but the majority of them are perfectly normal also. So I think that's all the major first trimester tests."

Now if you didn't have your first doctor's appointment last week, you may have it this week. Should you bring your partner? "Heck yeah. If they can sure, but they shouldn't be made to feel bad if they can't. The significant others are always welcome but the visits where they're going to get more bang for their buck (i.e.: paying for parking, missing work) would be the six or seven week appointment. Not all obstetricians have an ultrasound in their office, not all of them use it and nor necessarily should they but if there's going to be one then they want to be there. At the next visit, the ten or twelve week visit, is often the first time you can hear the baby's heartbeat so they may want to be there for that and then quite frankly the visits after that aren't all that exciting. There's usually an ultrasound about 20 weeks so they like to be there for that. Then quite frankly we don't usually see the dads until the mom is so close to her due date they're wondering why the baby's still in."

Now if you've gotten out of morning sickness so far, it may hit you now. A lot of moms to be get really worried if they can't hold food down. You can set that worry aside, for now. "The real risk is dehydration and that also brings up another myth, you get to eat for the baby. In the first trimester if you're really sick, solid food, let's face it, you don't have to go to Popeye's Chicken, this is not important. Really hydration is important. Now if your sickness is really interfering with your life, Dr. Swaim says your doctor wants to hear from you, "If moms are nauseous I think that could be a daytime call to the office: 'look I don't feel well, I'm not really vomiting' and then we can either give them advice or dietary advice, or give them, like I said, medications and then there's relief bands which may or may not work. There's something different for everyone. If someone is vomiting such that they're not able to keep fluids down then they need to call, it doesn't matter if it's two in the morning, that's something that we need to hear about. That's not even so much for the fetal health, that's for maternal health. If she's so dry she's not urinating anymore that's something we need to fix."

But you might avoid morning sickness altogether, in fact there's some evidence that if you're taking a multi-vitamin at the time of conception and in early pregnancy you may head off severe morning sickness. No one really knows why one woman will get morning sickness and another won't and for a woman who's pregnant more than once, it's entirely possibly she'll have morning sickness with one pregnancy and not another.

Now at seven weeks many women still have trouble shaking that fear of miscarriage even though the risk dropped to 10% once your baby's beautiful heart started beating. Regardless, the fear lingers and every ache and pain can put a mom to be into a panic. But pregnancy causes aches and pains. Dr. Swaim says there are a couple of reasons you could be having first trimester pain, "Sometimes women have cysts on their ovary in their first trimester which are perfectly normal, they're called corpus luteum cysts. They're producing hormones for the pregnancy and sometimes it can cause pain. People shouldn't worry about them, it's something that you can look at and know exactly what it is and sometimes it's a mass on the ovary that we think we know what it is, but aren't sure. Therefore we'll follow it, but that can be a cause of some discomfort. And some women do complain of some crampy feelings in the first trimester but as long as the pregnancy is known to be in the uterus then they're not particularly worrisome either, they don't herald miscarriage or anything like that without bleeding."

You may have already started having cravings, I craved starchy casseroles and everything my mom used to make. Indulge your cravings in moderation but remember even though you're eating for two you want to maintain a healthy diet and weight. Some moms to be will crave things that are well, not food; like chalk or dirt, cigarette buds or paint chips. This is called Pica and it's also normal but do not indulge those cravings, they may be caused by an iron deficiency or some other kind of nutritional deficiency so if you find yourself craving things that are not food, tell your doctor. Some people have food aversions during pregnancy. That's when it makes you sick to think of a food you would normally enjoy. Don't worry about skipping that food; just make sure you're getting adequate nutrition from other sources.

For the next several months of your pregnancy you'll be seeing your doctor about once a month, Dr. Swaim says that really that's all you need, "For people who are healthy we're doing surveillance here. Sometimes I feel like I have more fun talking to patients, getting to know them on a social level once we've established that their pregnancy is going well and that they're fine and healthy. They're not sick, they're pregnant. So enjoy it, you're seven weeks pregnant, you have 33 weeks to go until the big week, week 40.

That's your Pea in the Podcast for week seven of your pregnancy. Dr. Swaim and I will be back; we look forward to talking with you again next week. See you then. I'm Bonnie Petrie, thanks for listening.