Overview of Prenatal Testing

Many aspects of pregnancy and childbirth have changed in the past few generations. My grandmother gave birth to both of my aunts at home in bed in the 1930s and had never seen a doctor in her life until she begrudgingly allowed herself to be carted off to the hospital for my mother’s birth. My mother-in-law smoked throughout her pregnancy. Her obstetrician, like many in the 1950s, didn’t even allow her to come in for her first prenatal visit until she was well into her second trimester. When it was discovered that she was slightly anemic, doctor’s orders were that she drink red wine every night after dinner because it was “good for the blood.” She gave birth to my husband under general anesthesia while the father-to-be chain-smoked in the hospital waiting room.

Before we get too sentimental about “the good ol’ days” of prenatal ignorance, remember that as early as a half century ago, childbirth was still considered potentially dangerous or life threatening for the mother and frequently resulted in the death of the newborn. Birth defects—many of them severe—were a common occurrence, and because there was little understanding of chromosomal or genetic abnormalities, superstition led many people to ostracize parents of “abnormal” children.

Today, the availability of proper prenatal care and testing has significantly reduced many of the risks of childbirth, and because of early screening and diagnostic tests, parents are given a chance to prepare themselves for the possibility that their child might be born disabled and to educate themselves about their options.

With accurate over-the-counter pregnancy tests, women today can find out they are pregnant even before they miss a period, so proper prenatal care may begin right from the start, and women can reduce the risks of exposure to teratogenic substances (agents that can cause malformations of an embryo or fetus) in early pregnancy, when the embryo is most vulnerable.

If you are just beginning the journey to motherhood, rest assured that your chances of having a healthy baby are better now than at any point in history. Over the course of your pregnancy, your doctor will want to see you monthly, bi-weekly, and then weekly to keep track of your progress and the baby’s development. During these office visits, there are several routine prenatal tests that he or she will perform to insure that you and your baby are in good health.

Laboratory Blood Tests

Over the course of your pregnancy, your doctor will periodically test your blood to determine things like your blood type (A, B, AB, or O), your hemoglobin and blood sugar levels, whether or not your Rh factor is positive or negative, and your immunity to Rubella and possibly chickenpox. The doctor may also perform a screening to test for hepatitis B.

Women whose Rh factors are negative need to be treated to protect their babies from a possibly dangerous blood disorder, and those with a low red blood cell or hemoglobin count will be treated for anemia, which could increase the risk of pre-term delivery.

Urine Tests

It is common for expecting women to provide urine samples at their prenatal visits. Sugar found in a pregnant woman’s urine could be indicative of gestational diabetes, a potentially dangerous condition that needs to be monitored carefully throughout the pregnancy.

Those with protein in their urine may need to be checked for a urinary-tract infection, preeclampsia, or pregnancy-induced high blood pressure, all of which can be serious medical conditions that require treatment and monitoring.