Your combined screening appointment should be booked after your first antenatal appointment.
This is a very important appointment as it can screen for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome.
Bear in mind that this is a diagnostic test and will give you the risk of your baby acquiring these.
Which tests do they do during the combined screening?
The combined screening test is a two part test which includes:
- A blood test which is done a week prior to your nuchal ultrasound scan.
- A nuchal ultrasound scan will be performed at the Fetal medicine unit.
The combines screening blood test will screen the serum of free beta-human chorionic gonadotrophin (bhCG) and pregnancy-associated plasma protein A (PAPP-A).
Whereas, the combined screening ultrasound will measure the baby’s crown rump length (CRL) and the nuchal translucency (NT) of the fetus.
Which week of pregnancy should the combined screening test be taken?
The combined screening test should be carried about between week 10 and 14 of pregnancy.
My blood test was carried out at 11 weeks and my ultrasound was done a week later at 12 weeks.
Can I take the combined test if I am over 14 weeks pregnant?
If you are over 14 weeks pregnant you won’t be able to undergo the combined screening test and you will booked in for a quadruple test instead.
This test looks at 4 substances that may be present in the blood if the baby may be affected by these chromosomal conditions.
The quadruple test cannot be taken if you are over 20 weeks pregnant.
Can combined screening be used in twin pregnancies?
Yes, this is a test that is used in a multiple pregnancy too.
How to prepare before the combined screening test
I would recommend always going hydrated to both appointments as it will be easier for them to take a blood sample and this also makes ultrasound pictures clearer.
If you are a worrier, you may want to try relaxation techniques. This is a great test the NHS offer and there is plenty of support available for any concern.
What to expect at Combined screening blood test appointment
The combined screening appointment for the blood test will be carried out by a midwife.
She will go through all your results from your first midwifery antenatal appointment and assess how you are feeling.
They will also measure your blood pressure and draw some blood to analyse for the combined screening.
The results will be available to you after your nuchal ultrasound scan for the combined screening test.
What to expect at your first trimester ultrasound scanned for the combined screening
You will be seen at your hospital’s Fetal medicine unit and undergo a detailed ultrasound scan.
The ultrasound scan is aimed at measuring the crown rump length and nuchal translucency.
They will confirm:
- An approximate generational age, which is how many weeks old your baby may be.
- Wether you are having a single or multiple pregnancies (twins, triplets, etc)
- Fetal heart activity
- Crown rump length
- Nuchal translucency
- Biparietal diameter
- The Fetal anatomy of the skull, brain, abdomen, stomach, bladder, hands and feet.
- If the development of the baby is normal.
You will get to see your baby for the first time on the ultrasound. Although, it is for checking that everything is ok with the baby, it’s such a magical moment.
You will be able to see your baby sleeping , drinking amniotic fluid, sucking their thumb or moving around.
When will I get the results of the combined screening test?
The results are assessed as higher risk and lower risk. Higher risk includes any result of 1 in 150 or higher (such as 1 in 120, 1 in 50, 1 in 8, etc.) and lower risk includes below 1 in 150 is considered to be a ‘lower chance’. (This is less than 0.7%, such as 1 in 200, 1 in 850, 1 in 4400, etc.).
Bear in mind that if you are assessed as high risk it doesn’t necessarily mean your baby has any of the chromosomal conditions.
At the end of this ultrasound appointment you will be provided with the results both verbally by the doctor and in the form of a report which gets added to your maternity notes.
They will combine the results of both tests conducted and assess if your Fetal development is normal or if there is any risk for Trisomy 13,18 and 21.
The report from this first trimester ultrasound scan is very detailed and you will be able to have a deeper understanding of your baby’s results.
They will also set up the appointment for your 20-22 weeks anomaly scan.
They will also provide you with 3 copies of your ultrasound which is just so special at this point.
How reliable is the combined screening?
It tends to identify 85% of babies with Down syndrome and 80% of babies with Edwards or Patau’s syndrome.
What happens if your results show you are high risk?
If your test results put you in a higher risk category you can choose to:
- not to have further testing
- have a second screening test (called NIPT) to obtain a more accurate screening result, in the form of a blood DNA test.
- have a diagnostic test straight away (a diagnostic test will give you definite answer rather than a risk assessment) this includes CVS or amniocentesis.
Can the combined screening test identify other anomalies?
Generally, if the amount of fluid in the baby’s neck increases at 3.5mm this can indicate some issues which include genetic, chromosomal or structural problems.
Further testing would be offered in this case.
My experience at my 12 week combined screening appointment
I went to my combined screening with my second mom and unfortunately I seemed to have GBS which I have never encountered in my previous pregnancy.
However, this is a whole different topic for another post!!! I hate you GBS!
The blood test was easy nothing out of the ordinary. They inform you the results will be given to you the after 7 days at your dating scan.
I went to my first trimester ultrasound scan with my partner and we were so anxious as the night before I had experienced bleeding.
It was quite nerve racking but thank god all was well. The baby was fine and the bleeding is just what seems to happen to me in pregnancy. I had the same issue with my previous pregnancy unfortunately.
We went out for lunch to enjoy this special day as it was extremely emotional and I am not going to lie a lot of tears.
My previous pregnancy was hell and I guess that probably made me emotional too.
Here’s me and my first picture of my little one.
I hope this helps and prepares for what to expect at your combined screening appointment and first ultrasound scan.
How was your experience? Are you excited to see your little one? Comment below in the comments section and let me know.
