Pregnancy scans can be very exciting as they show the first glimpse of your growing baby. Here are your pre-natal ultrasound options.
Going for the first antenatal scan is one of the highlights of pregnancy for a woman who is expecting. An ultrasound scan, also known as a sonogram, is a procedure that uses high frequency sound waves to create an image of part of the inside of the body. A small handheld sensor called a transducer is used to direct ultrasound waves at your body. When the sound waves hit an object, such as the womb, they bounce back as an echo.
At your scan, you will be asked to loosen your clothing from around your abdomen and lie on a couch so that the midwife or doctor can apply gel to your abdomen. The transducor is then placed on your abdomen and moved around to produce pictures. The gel can be easily wiped off afterwards. These ultrasound echoes are then converted into an image by a computer.
The number of scans you have depends on whether your pregnancy is considered high or low risk. For example, if you have had previous complications in a pregnancy, suffer from high blood pressure, or are expecting twins – you might be offered more scans to keep an eye on your baby’s growth and health.
Early pregnancy scans
If you have an early pregnancy scan (from six weeks to 10 weeks), it is more likely to be a transvaginal scan. A scanning device is inserted into the vagina – some women might feel a bit of discomfort but it should not cause any pain. This type of scan allows the ultrasound to get closer to the embryo or fetus, which can give a more detailed result than a transabdominal scan in early pregnancy. These scans are generally used to if there is a question about whether the mother has suffered a miscarriage, or if the pregnancy is ectopic (contained in the fallopian tube).
First trimester scan
As part of your antenatal care, your midwife will offer you a dating scan that will give you a date for the birth of your baby. This scan will not be able to determine what gender your baby is at this early point, but it will identify if there is just one baby in there and will confirm if your pregnancy is viable. This scan, which normally takes place between 10 and 13 weeks, will also:
- check that your baby’s heart is beating and that he’s developing normally
- check for any abnormalities
- check that the pregnancy is situated in the womb
- check whether the age of the baby agrees with your own dates
The anomaly scan
This scan is normally done at the 18-22 week stage and will examine your baby’s organs, take measurements of limb lengths and stomach and head circumference. These scans, however, are not routine in many maternity units in Ireland. If you want to know your baby’s gender, this can usually be seen at this scan – although the sonographer will not tell you the sex of your baby unless you ask. But if your baby’s lying in an awkward position, it’s not always easy to tell. It’s worth remembering that the main objective of this scan is to check that your baby is developing normally, rather than whether you’re expecting a boy or girl.
Sonographers will be looking out for a list of conditions. Detecting any abnormalites can allow doctors and parents to plan and prepare for various outcomes.
The position of your placenta will also be checked. If it is found to be lying low in your uterus, you will have another scan in the third trimester to check its position, but by then the placenta will probably have moved away from your cervix.
3D and 4D scans
What benefits do 3D and 4D scans offer over the normal scans that a pregnant lady is offered in a maternity hospital?
The 3D/4D baby scans gives you a unique opportunity to see what your unborn baby is up to during pregnancy. Time is taken to capture 3D images and 4D video clips – the fourth dimension is the moving part.
From 25 weeks onwards, the face of your baby becomes very clear and features can be identified in three dimension. This is a great bonding experience – especially for the dads.
Some of the things we have witnessed on 3d4d scans include babies yawning, drinking, smiling, sucking their thumbs, putting their feet or umbilical cords into there mouths, opening their eyes and even pulling grumpy faces!
Are 3D and 4D pre-natal scans useful for spotting potential problems with a baby’s development in the womb?
3D/4D imaging shows the surface of the baby and not the internal organs. They can be useful for assessing some anomalies such as facial defects like cleft lip, open spina bifida, clubbed feet etc. but they are not typically diagnostic scans. 2D (black and white) scans see straight through the baby, allowing the sonographer to examine the internal organs. Most anomalies affect the internal organs, so the 2D scan will remain the gold standard in fetal imaging.
The Ultrasound Suite in Bray and Grafton Street is one of the few centres that provide a 2D well-being baby scan in conjunction with your 3D/4D baby scan all for one reasonable price, as they believe that the health of the baby is of utmost importance.
What stage of pregnancy is the best time for a woman to have a 3D or 4D scan?
These scans can be performed from 12 weeks onwards. The images become clearer and more realistic as the pregnancy goes on. It is important to have enough fluid around the baby and for the baby to be big enough to produce realistic images. 30 weeks gestation is the optimal time to get the scan done.
Some patients are too excited to wait that long, so they have a mini 3D/4D scan at about 18 weeks (when the gender can be seen too) and another mini 3D/4D scan at 30 weeks.
Clinical Specialist Sonographer
The Ultrasound Suite
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Maternity options in Ireland
5 things you need to know about pregnancy