Antenatal screening is one of the fundamental ways of checking the health of your unborn baby and is a way of detecting early problems and illness. Antenatal screening is offered at different points throughout your antenatal journey, in this article Rachel Curran, midwife and Founder of Bitbaby explains the antental screening tests you may be offered and what to expect from your antenatal appointments.
During your booking appointment, a midwife will take a full detailed history about you, your partner and your families. The information that is required is any information that may impact upon yours or your baby’s well being during your pregnancy. Antenatal Screening is offered during this consultation.
A routine set of blood tests are performed so that we can have a baseline reading of certain blood results. To ensure your well being early in your pregnancy. A Full Blood Count checks your iron levels, as they can become depleted further along in your pregnancy. Also to ensure there are no signs of infection.
We need to identify your blood group ( as this is important to know as a precaution ). Also during this test we need to identify what your Rhesus Factor is. You can either be Rhesus Positive or Rhesus Negative. If you are Rhesus Positive this means that your red blood cells carry a Rhesus factor protein. If your Rhesus Negative then this is absent. It is of no harm to your wellbeing when not pregnant. However being Rhesus negative is significant during pregnancy, as your unborn baby may have a rhesus positive blood group. We do not screen unborn babies for their rhesus factor, therefore if we identify that you are Rhesus Negative you will be offered Anti D injection.
Anti D injection is given as a precaution to prevent antibodies developing if rhesus negative blood has mixed with rhesus positive blood. One attacks the other via an immune response.
Further optional screening blood tests Check for immunity to rubella (German measles), and test for hepatitis B, syphilis, and HIV and other sexually transmitted diseases. The reason we offer these tests is because treatment has advanced and early detection, early treatment aims to prevent/reduce the exposure to your unborn baby.
Usually between 10 to 13 weeks you will have a Dating Scan. A dating scan is an ultrasound examination which is performed in order to establish the gestational age of the pregnancy. Dating scans also reveal other important information such as:
● the number of babies and gestation sacs
● presence of a heart beat
● size of your unborn baby, from which the gestational age is estimated
● unusual features of the uterus such as the shape or the presence of fibroids.
During this scan it is important to note that we are ruling out some potential abnormalities also, we are checking for the presence of brain and all limbs as well as a heartbeat. Also during this scan a further screening test can be performed.
Combined Screening Test
There is a fluid filled space at the back of the unborn baby’s neck that is called the nuchal fold. If the measurement of this space is increased in size this may be an indication that the unborn baby may be affected by an abnormality. As an addition to this measurement there is a blood test that can be performed on the same day. This blood test checks for certain markers that if raised may also be an indicator for fetal abnormalities. Maternal age is taken into consideration also. The results of the combined test give a risk factor ratio.
This is not a diagnostic test.
If you consent to a combined screening test and your risk factor result is raised you may be offered diagnostic tests. Diagnostic tests are invasive and carry risks. If you are offered particular tests all of the aspects, procedure, risk and outcomes will be discussed in depth with you by health professionals.
For further information or advice please contact us via the contact me form
Written 2019 by Rachel Curran midwife and founder of Bit Baby
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