Screening for a healthy pregnancy

Congratulations, your pregnancy test is positive; and so the journey begins.  While we know for most people pregnancy is a normal and natural part of life and will continue without complication, it is important to ensure the health and wellbeing of you and your baby throughout your journey. There are certain tests and screening measures that are considered routine during a healthy pregnancy and are recommended to ensure you and your baby are as healthy as can be.  Both midwives and obstetricians often recommend what is often referred to as ‘routine screening’ and we understand that most patients happily accept request forms for blood tests and ultrasounds along with the health providers  advice, but we want you to be as active a part of this journey as you can be, understanding all the steps along the way – so this article will explain routine screening during a healthy pregnancy, to ensure you have a greater insight into what it all means.

First trimester

Usually once your pregnancy is confirmed by blood test, your GP will order a test for routine antenatal screening. These blood tests include a screening of the mother’s general health as well as infectious diseases that may impact your pregnancy and or delivery such as HIV, Hepatitis, Chickenpox (varicella) and Rubella. This test also shows your blood type, which is important, particularly if you are a negative blood group.  Your GP may also order a dating scan, which compliments the blood test which confirmed your pregnancy in ensuring viability of your pregnancy and clarifying gestation and estimated due date. It is during the first trimester that your GP will refer you to Kindred Midwifery Obstetric and Gynaecology, and we will book your initial appointment around 10 weeks. A dating scan can also be performed in the Kindred clinic by one of our Obstetricians

Toward the end of first trimester testing will be recommended to screen for genetic disorders or chromosomal abnormalities. The aim of prenatal screening tests like these is to determine if the baby has an increased risk of conditions such as Down syndrome and to check for any physical defects. This screening is most commonly done by combination of blood test (Maternal serum screening) and ultrasound, which is called Nuchal Translucency. The best time for this is between 11 weeks and 13 weeks and six days gestation. The blood test can be performed prior to the ultrasound and this, in combination with measuring the nuchal translucency (thickness of fluid-filled tissue at the back of the baby’s neck) by ultrasound, gives results in a risk ratio for Down syndrome and other less common chromosomal abnormalities. Other Non-Invasive Prenatal Testing (NIPT) such as Verify or Panorama screening may be offered also; these tests allow the baby’s DNA to be collected from the mother’s blood. Your Obstetrician will discuss these options with you at your first appointment.

Second Trimester

During the second trimester a routine morphology ultrasound will be recommended. This takes place between 18-20 weeks gestation and gives a good assessment of the growth and development of the baby and general well being of the pregnancy. Specifically, the morphology ultrasounds assesses the size of the baby compared with gestation and estimated due date, development of the baby including measurements of each part of the body and blood flow, location of the placenta, and amount of amniotic fluid, it is the ultrasound where you can find out if you are having a boy or a girl! If all is well with the 18-20 week scan, this is often the last clinically indicated ultrasound in a healthy pregnancy. Of course, if there is anything that requires further assessment, your Obstetrician will discuss this with you and order further screening as needed.

Moving into the third trimester, the main group of blood tests in pregnancy will be ordered. These are best performed between 24-28 weeks and include an assessment of a mother’s full blood count, giving a good indication of iron levels, an antibody screen if you are a negative blood group, as well as the glucose tolerance test. The glucose tolerance test screens for gestational diabetes and is recommended in all pregnant women. If you have risk factors for gestational diabetes, you may have completed this test earlier in pregnancy. These blood tests require you to be fasting, and take 2 hours to complete in total. For more information regarding the glucose tolerance test, please see the previous blog about gestational diabetes.

Third Trimester

During the third trimester screening for the maintenance of a healthy pregnancy is recommended, including a blood test for the mother’s general health with full blood count, an antibody screen if you are a negative blood group, and sometimes a urine test. If there is anything that requires follow-up from your ultrasound at 18-20 weeks, a repeat ultrasound will be ordered in third trimester, usually around 32-34 weeks. This may be the case if confirmation of the location of the placenta is required, or if additional monitoring of the baby’s growth and development is necessary.
Of course, if needs or risks arise throughout your pregnancy, tests will be ordered in addition to the routine screening mentioned above, as is clinically indicated in your specific situation, such as thyroid function, specific iron testing or screening for blood pressure conditions. At each of your routine check ups, the obstetrician or midwife will palpate your abdomen and take measurement of the baby’s growth, if at any time there is concern with the growth of your baby, an additional ultrasound will be ordered. Remember that the routine screening offered throughout your pregnancy is to ensure the wellbeing of you and your baby during a healthy pregnancy, and that the Midwife or  Doctor will discuss and order screening in addition to this if it is clinically indicated. Some friends or family may have had different blood tests or ultrasounds throughout their pregnancy, as was appropriate for their specific situation.

Kindred is a collaborative practice with both midwifery and obstetric care who’s aim is to provide individualised care that is developed with you and your needs at the centre so we welcome the opportunity to discuss this ar any other questions and concerns you may have as we aim to support you every step of your journey.