In the last post, I reviewed the importance of establishing a due date. The next issue we address early in the pregnancy entails assessing the woman’s overall health with particular attention to any medical problems that may affect her health and that of the baby during the pregnancy.
We start by obtaining a detailed medical history. Assuming there are no preexisting conditions such as diabetes or hypertension, we then proceed to run a series of routine blood tests. The only ones that are really necessary for most women is a blood type, blood count, and urine culture. The blood typing will assess for any risk of developing antibodies against the baby’s blood cells. This is a serious complication that could occur during a second pregnancy if the woman’s Rh type is negative. Fortunately, this condition called “hemolytic disease of the newborn” is now very rare precisely because we test for and preventively treat women who may be susceptible. Women who are “Rh negative,” will receive a medication called “Rhogam,” around 28 weeks gestation in order to prevent her body from developing antibodies against her preborn infant’s blood cells. The success of this routine test and treatment is truly one of the best success stories in modern obstetrics, wherein the incidence of hemolytic disease of the newborn is rarely seen anymore. Next, the blood count test will assess for any underlying anemia which may need to be treated. Finally, the urine culture will test for any undiagnosed urinary tract infection which during pregnancy is more likely to spread to the kidneys.
The other routine testing is controversial and often lacks sound scientific rationale. These can be divided into two categories. The first is that of infectious disease testing (for the variety primarily transmitted by sexual contact).
In the U.S., most obstetricians will routinely test for gonorrhea, chlamydia, hepatitis B, syphilis, and HIV. In my experience, it is highly unlikely that a woman will have any of these infections if she lacks both symptoms and potential exposure based on her history. The pertinent history is whether she has abused IV drugs like heroin or whether or not she is in a mutually monogamous sexual relationship (as in a faithful marriage). Rather than utilizing the rational approach of simply basing our testing on the individual patient’s actual risk factors, we have resorted to the politically correct yet inefficient, wasteful, and unscientific approach of assuming all our patients are IV drug abusers routinely engaging in sexual relationships with multiple partners. I have never even met another physician who has diagnosed HIV, syphilis, or hepatitis B in a woman based on these “routine,” tests alone in a woman without known risk factors. Ye,t we continue to use this approach rather than run the risk of being labeled “ judgmental,” for utilizing these tests only on the women known to be at risk. During an era of ballooning health care costs, this obvious waste or resources should certainly be addressed. We may even have to let go of our social engineering agenda of treating all manner of sexual activity and perversions as normative. To do so, however, would run the risk of exposing the common sense truth that certain behaviors entail commensurate risk that pose real physical danger to a woman and her preborn child.
The second type of routine prenatal testing is even more problematic in terms of medical legitimacy. I am speaking here of those tests used to supposedly assess the risk of having a child with a genetic or other congenital defect. Among these are the “triple screen” (recently replaced in most areas by the “quadruple screen”), nuchal translucency ultrasound (often done in combination with a serum PAPP-A test and HCG), amniocentesis, and chorionic villus sampling. These tests can be grouped into two categories.
The first would be that of the non-invasive “screening” tests, which will actually only provide a statistical number giving a particular % risk of having a child with Down’s Syndrome for instance. Among this first group are the “triple screen,” the “quadruple screen,” and the nuchal translucency (NT) ultrasound combined with a PAPP-A/HCG blood tests. The relative advantage of these tests is that they are non-invasive in that they pose no direct risk of harm to the baby. The major drawback to this group of tests is that they are very inaccurate and misleading. For example, a cut-off of 1/250 or 0.4% is often used to give a woman an “abnormal result.” In other words, 99.6 % of women given this “abnormal” test result have perfectly normal children; yet, for the rest of their pregnancy they live with the fear and anxiety that something might be terribly wrong with their child. Many, if not most, of these women will feel obliged to proceed with the next level of testing–the invasive and diagnostic.
The only definitive prenatal testing that is truly diagnostic is also invasive and poses risk to both the mother and baby. The most widely available test in this category is amniocentesis. This procedure requires piercing the woman’s abdomen, uterus, and the fetal amniotic sac with a long needle in order to obtain fetal cells from the amniotic fluid. This test poses risk of infection to mother and baby as well as the risk of miscarriage. The next test is even more invasive and entails inserting a long cannula through the cervix to obtain a piece of the placenta for testing purposes. While this test is more accurate and can be done earlier, it also carries even greater risk to mother and baby.
Why, one might ask, would we recommend such tests to our patients? The answer is quite simple, yet unpleasant. We offer them out of fear that a woman might have a child born with a genetic defect who would then sue us for wrongful life! This sort of medical liability would be based on the woman not being offered all of her “options,” in regards to prenatal testing. In the U.S., an entire field of “pseudoscience” has been dedicated to various techniques and schedules of prenatal screening and testing. They have as their end, the earliest detection possible of genetic or congenital abnormalities. They exist directly as a result of legalized and widely available induced abortion. The early detection emphasized because more abortionists are available to perform and women are lest resistant have to early abortions. Therefore, women should be aware that if induced abortion is not a procedure they would consider, there is no good reason to procure one of these early screening tests. We must acknowledge, however, that it has been argued that information by itself is a good and even an abnormal result could be helpful for the mother not pursuing abortion by allowing her to prepare emotionally. Unfortunately, this argument overlooks the problems of inaccuracy associated with the non-invasive tests and those of risk associated with the invasive tests.
In summary, I routinely inform my patients of the availability of all these tests, yet I advise against their use. I do, however, advise them to obtain a routine 20 week anatomy ultrasound which serves the legitimate purpose of a physical exam of sorts for the preborn baby. If there are any medical conditions for which we can meaningfully intervene or prepare for, we are typically able to detect them during this ultrasound. My patients are most appreciative of this frank, no-nonsense counseling that treats them as responsible adults able to make informed decisions. Contrast this with the overbearing “paternalism” imposed by the wasteful “one-size fits all,” approach promoted by the mainstream medical profession. Next time, we’ll step into the much less controversial matters of the diagnosis and treatment of diabetes in pregnancy.