What to expect: early pregnancy scans

The first time you see your baby will most likely be on the black-and-white screen at your local ultrasound provider, explains Yvonne Eve Walus.

In addition to monitoring of your pregnancy during check-up appointments, you can undergo a number of tests to get more information about your baby’s growth and development, as well as how your body is coping with the pregnancy. You may welcome the additional information about your baby’s health, and whether there’s any risk of complications – or you may find these tests intrusive, and the knowledge unwelcome. It is entirely your decision whether or not to have these tests, so speak to your midwife or doctor about what they recommend in your situation.

Before you decide whether or not to have a scan, consider the following questions:

  • Will it provide the information I want or need?
  • Will the information lead to changes in the way I look after myself in this pregnancy?
  • Can my partner and I cope with the possibility that the test will raise concerns about the baby?
  • Does the test carry any risks for me or the baby?
  • How accurate is the test?
  • What is the likely outcome if I choose not to have the test?

Common fears

Can repeated scans hurt the baby? Scans use ultrasound, which is a form of non-ionising radiation. The medical profession considers ultrasound scans safe to pregnant women and their babies. Some people, however, are concerned that these scans could be harmful, especially during the first trimester when the baby’s major organ systems are being formed.

The dating scan (also known as the nuchal translucency scan)

This is an abdominal ultrasound scan done at about 10-14 weeks. It assesses the gestational age (that is, how pregnant you are) by measuring the baby’s crown-to-rump length. In addition, this scan estimates the risk of your baby having Down syndrome or another rare genetic condition, but it won’t be totally conclusive. If the scan points to a high likelihood of a medical condition, you will be offered more tests to find out for sure. This scan will also reveal whether you’re having more than one baby, although the midwife can usually detect that by listening to the heartbeat in your bump. To prepare for the scan, you will need to make sure your bladder is quite full, so that the ultrasound has the best chance of providing a clear picture. The scan itself is painless, non-intrusive (although the gel the technician rubs on your belly may be a bit cold), and produces an image of your baby on a computer screen. At the end, you will be given a printout or memory stick of your baby’s ultrasound “photo”, which you can show to your family or friends, though it is important to keep in mind that this photo is not the main purpose of the scan. From the Ministry of Health website: “The Ministry of Health currently funds First Trimester Combined Screening. This involves a blood test that is taken when you are between 9 to 13 weeks pregnant that measures a couple of blood proteins, and a Nuchal Translucency ultrasound scan when you are 11 to 14 weeks pregnant. (You may be asked to pay a surcharge for this scan.) The results of these tests are combined with information about your age and weight to calculate the risk of your baby having Down syndrome.”

When can you find out the baby’s gender?

Although some doctors claim that they can predict the baby’s gender at the 12-week scan with about 85% certainty, others prefer to wait until they can be very sure. This is why the anatomy scan (at 18-22 weeks) is the one when you’re given the option to learn the baby’s gender or to keep it a surprise. There is one other way to find out: If you need to undergo additional tests at 12 weeks (CVS or sampling amniotic fluid), they may also determine the baby’s gender. However, these tests do come with risks, so they’re never done for that purpose alone.

Anatomy scan

The anatomy scan is available when you are 18 to 22 weeks pregnant, and its aim is to check your baby’s growth progress, as well as to identify any developmental concerns. The ultrasound tech will examine the baby’s brain, and count the heart chambers, kidneys, fingers, and toes. To get the best overall picture, the tech will take many different views from several angles. This may take 30 minutes or more, but you may be lucky enough to spot your baby’s heart, the spine, the face, arms, and legs – or the tech may point them out to you. If you decide that you’d like to know, this is the scan that can tell you what gender your baby is. However, don’t be disappointed if the baby is lying with his or her legs crossed and refuses to reveal this particular bit of information.

Third trimester scans

Scans in the third trimester are usually performed only to follow-up any potential problems raised at the anatomy scan, or to monitor the growth of a baby who seems to be too small or too large for the gestational age, or because you’re having a multiple birth (twins, triplets, or more).

First antenatal blood test

When you first see your midwife (or specialist doctor) during pregnancy, you will be offered a blood test. This blood test is free, and it checks:

  • Your blood group and rhesus factor (if you are rhesus negative, your Lead Maternity Carer will explain the implications for your pregnancy).
  • Your haemoglobin (the amount of iron in your blood).
  • Whether there are any antibodies that may be harmful to your baby.
  • Whether you are immune to rubella.
  • Whether you are a hepatitis B carrier.
  • Whether you have syphilis.
  • Whether you have HIV (treatment can help to keep you healthy and well and reduce the chance of HIV passing to your baby).
  • Whether you have diabetes or are at risk of developing diabetes.

3D/4D scans

The normal two-dimensional scans are exciting, but many parents find it tricky to use them to visualise the baby. 3D scans take those flat, difficult-to-interpret images, and create a picture of your baby in three dimensions.  4D scans go even further: They are mini-videos that show moving 3D images of your baby.  The 3D or 4D ultrasound is sometimes used to examine the surface of the face or another part of the baby. In addition to providing amazing lifelike pictures as keepsakes, this technology is used to enhance visualisation of any abnormalities, such as cleft lip, so that parents can understand what the doctors are describing.

Other tests

Throughout your pregnancy, you will be offered other tests to ensure that you and your baby are healthy and well. This includes regularly checking your blood pressure, urine (to test for bacterial or fungal infection, as well as for the presence of sugar which may point to gestational diabetes), weight, the size of your baby bump, and the baby’s heartbeat. These tests are to check that the baby is growing as expected and you are not showing signs of any problems.

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