The antenatal visits are incomplete without some basic investigations. These are specifically chosen since they screen for the most common conditions that occur in pregnancy and are associated with increased risk either to the mother and/or the baby. The tests routinely done include:
- Hemoglobin – this is the blood level test which is usually done to determine if the mother is anemic. The requirements for iron in pregnancy increase due to the growing baby and hence mothers are at risk of lower blood level/anemia. If anemia is present, iron supplementation is given to increase the blood level. This is crucial since hemoglobin delivers oxygen to the body and the baby during the pregnancy. In addition, during delivery it is expected that the mother will lose some blood which lowers the blood level. It is therefore necessary to ensure that the blood level is high enough to allow for other to safely go through delivery.
- Blood group – blood group has two components, the group (O, A, B or AB) and the Rhesus factor (positive or negative). The Rhesus factor is what is crucial during pregnancy. If a mother is rhesus negative, and the baby is rhesus positive, then the mothers’ blood produces antibodies against the rhesus positive blood. These antibodies will then attack and destroy the baby’s blood cells. This attack does not usually happen in the first pregnancy, but rather affects subsequent pregnancies. Testing is crucial since once it is ascertained that a mother is rhesus negative, medication to prevent the production of antibodies can be administered.
- Blood sugar – this is done to screen for diabetes mellitus. There are mothers who develop diabetes in pregnancy which needs to be controlled to allow for the normal growth of the baby. The diabetes can resolve after delivery but it may also persist thereafter and thus follow up even after delivery is advisable if diabetes occurs during pregnancy.
- Hepatitis B, HIV, and syphilis – these blood tests are done to screen for these infections which can be transmitted from mother to baby during pregnancy. These diseases left undiagnosed have serious consequences on the outcome of the baby. It is important for these to be diagnosed if present in order to take steps to reduce the likelihood of transmission to the baby.
- Urinalysis – the urine test is performed in every antenatal visit to screen for urinary tract infections. In some cases, bacterial infection can be present without any symptoms (asymptomatic bacteriuria) and hence the need for routine testing even when no symptoms exist. Urinary tract infections can increase the risk of premature labor or progress to the more serious infection of the kidneys. Early detection and treatment in pregnancy cannot be overlooked.
- Ultrasound – it is recommended that at least 3 obstetric ultrasounds should be done during pregnancy. However, there is no limitation on the number in the event more are required since they are not harmful to the mother or the baby. One ultrasound is done at each trimester.
- In the first trimester the ultrasound is mainly to confirm the dates. This is useful since many mothers either had irregular cycles or were on contraceptives and are thus not sure about the dates of their last period. The ultrasound ensures that the dating of the pregnancy is done accurately.
- In the second trimester, the ultrasound is done at about 20 weeks to screen the baby for any abnormalities of the heart, brain and the abdomen.
- In the 3rd trimester, the ultrasound is done mainly to confirm the position of the baby (head down or breech) and also the position of the placenta.
However, in all the ultrasounds, there are other general features of the pregnancy that are monitored. Other tests may be required but the above are the basic that are required in all pregnancies as part of antenatal care.