Ultrasounds
Ultrasounds have become a routine part of most pregnancies. They are used to check your baby’s dates, measurements, feotal development, the placenta, amniotic fluids and lots more. Some people may have an early ultrasound to check how far along they are if there is any uncertainty of when the baby was conceived but most people won’t have their first ultrasound till they are 12 weeks. The next ultrasound is done at 18 weeks and if all is well with the baby this will probably be the last ultrasound.
The 12 Week Nuchal Ultrasound - During this ultrasound the scan operator measures the fold of the neck to determine whether your baby is at high risk for heart defects, down’s syndrome or other chromosomal abnormalities. If your baby has a thick neck fold and is thought to be at risk you will be offered an amniocentesis, Chorionic Villus Sampling (CVS) or Cordocentesis. Some people like to know if their child has disabilities so they have the option of aborting others feel it’s not necessary as they wouldn’t abort even if their baby had a genetic abnormality. It is a very important and personal choice and you and your partner should discuss what you would do in different situations to make the best choice for your family. The operator will also check your baby’s measurements to confirm your due date, check for twins/multiples, to check the position of the placenta and the amount of amniotic fluid.
The 18 Week Ultrasound - During this ultrasound the operator will once again check the baby’s length, placenta and amniotic fluid. They will also make sure the heart has developed into a four chambered heart and that all the major organs are present and functioning. This is the most enjoyable scan for the parents as you get to see your baby in action. You will see your baby moving its arms and legs, fingers and toes. There will be the nose, eyes, ears and mouth. Some parents may even see their baby yawn or hiccup or grab hold of the umbilical cord and yes the genitalia can be seen at this scan (if your baby co-operates) so if you’d like you can ask the operator if you have a little boy or a little girl.
Invasive Testing will only be recommended if there is a risk of chromosomal or genetic problems. Reasons could include family history, your age or abnormal ultrasound results. A small percentage of these test do result in a miscarriage so it is important to discuss the risks involved with your health care provider and talk about your options and possible outcomes with your partner before deciding if you would like to go ahead with them. The tests you are likely to be offered are Chorionic Villus Sampling (CVS) , amniocentesis or Cordocentesis. It will depend how far along in your pregnancy your are as to which one you will be offered.
Chorionic Villus Sampling (CVS) – CVS can be done from around 11 weeks gestation. You will be given an ultrasound to check where about in the uterus your baby is so they can determine which spot is safest to put in the needle. A fine needle will then be inserted and a small sample of the placenta will be taken. The procedure should take around 10-20 minutes, with results being available in around 7 days.
Amniocentesis – Is usually performed between weeks 14 – 26. Again an ultrasound is used to detect the position of the baby then a fine needle is inserted into the womb and a sample of the amniotic fluid is taken. It takes around 2 weeks to get the results back.
Cordocentesis - This is where the needle is inserted into the umbilical cord with the help of an ultrasound and a sample is taken. It can be done from around week 18-24.