Pregnancy Ultrasounds

          Explained by Gillian Martin DCR(R), PgDip USS. 

Lead Songrapher, First Choice Baby Scan.

 First Choice Baby Scans


Antenatal (pregnancy) Ultrasound is something that every lady who has ever been pregnant has heard of – but do they really under stand what can be seen, when and does a “normal” ultrasound mean that the baby/ fetus is perfect.


Early Pregnancy :

This  can be a little bit of a mine field / challenging both for the expectant parents and for the Sonographer (person who performs ultrasound). At approximately 5 weeks post last menstrual period (LMP) a small “black hole” can be demonstrated within the endometrium (lining of the womb). This black hole is the gestation sac / pregnancy sac. Within this develops a yolk sac, then embryo. When the embryo measures 7mm it should have its own little heart beating. Obviously things can go wrong very early ( 1 in 4 pregnancies end in early miscarriage). Sometimes a hormone test (serum beta hCG) will be required to accompany ultrasound. If this reaches 1000u/L  the Sonographer should be able to find a sac within the womb – obviously if not this would indicate an ectopic pregnancy . If you are having multiple are having a multiple pregnancy (twins / triplets) this should be pick up at this stage. The type of twinning (identical / not) can also be assess

 Early Pregnancy Scan


Dating Scan : 

 The National Institute for Clinical Excellence (NICE) state that all women should be offered a scan after 8 weeks gestation to date the pregnancy. The Fetal Anomaly Screening programme (FASP) state that women inEnglandshould be offered first trimester screening for Downs Syndrome. In most English NHS hospital these 2 scans are emerged to form a Nuchal Translucency (NT) scan . The NT is a potential space at the back of baby’s neck, and the basic theory is the thicker to NT the more likely baby is of havingDowns’s syndrome. The measurement of NT, baby’s length, mother’s age and 2 factors in mother’s blood are analysised to give an individual risk for the likelihood of Downs syndrome.  The NHS deems a risk less then 1:150 has a high risk pregnancy and the mother would than be offered a diagnostic test (eg amniocentesis). Of course if you haven’t had an early scan, it is at this scan that you could find out that there is more than one baby in there….be prepared for a shock!


The Anomaly Scan :

The fetal anomaly scan is a likely like a MOT for your baby.  The Sonographer will assess baby’s growth by measuring around baby’s head and tummy, and also the baby’s thigh bone (femur length). Other things assessed on this scan will be baby’s brain, spine, limbs and organs eg heart, stomach, kidneys and bladder. More information for what we look for can be found on

It is at this scan that in most hospitals you can (if you wish) ask the Sonographer about baby’s gender – but remember it’s not 100% accurate.

Plus it must be remembered that ultrasound in obstetrics is being used as a screening tool as well as for diagnostics. It will not pick up all problems with baby- especially chromosomal problems (eg Downs Syndrome) and cardiac defects.

If you are deemed as a routine pregnancy this will be the final scan you will have on the NHS, obviously if you are having twins, have a poor obstetrical history (problems in previous pregnancy) or if midwife is concerned you will be referred for further imaging.



Depending on which company you go to will determine when you can have this scan, how much it will cost and what you will receive for your money.

Most 3D / 4D scans are performed between 24 – 32 weeks gestation. This is for a number of reasons including at this gestation the fetus begins to put on weight thus looks like a real baby and not skeletal. 3D imaging depends on the amount of liquor (amniotic fluid); to get nice pictures the Sonographer requires fetus to have a good pool of fluid in front of face. It is during this gestational age that your liquor volume will peak. Plus it is before baby becomes deep within the pelvis ready for birth.

I often get asked …..what is the difference between 3D and 4D? Well without going into a lot of physics which I think will bore you death I will quickly tell.  Conventional 2D ultrasound sends a sound wave into the body in a straight line, this bounces back from difference structures. The time it takes to come back always the machine to differentiate between structures. 3D ultrasound sends the same “dose” of ultrasound into the body in a sweep, it thus returns in a sweep. It is the electronics within the machine that reconstructs a 3D image. 4D is a 3D image which moves.

As part of the scan (at First Choice Baby Scan) we will perform an assessment of baby’s growth and general well being. We can also assess baby’s gender if required.

The advantage of having a 4D ultrasound scan is that the baby appears “more real” to the parents (it looks like a baby) and they get to spy on the secret’s of the womb.


As you can see… during 4D ultrasound you get a true appreciation of how your baby looks, and what little gestures they do ( sometimes including naughty hand gestures!). I quite often get asked ….does these really look like the baby….well judge for yourself



A little about myself :

Gillian Martin; Lead Sonographer @ First Choice Baby Scan

I am a mum of two beautiful daughters and state registered Radiographer who has specialised in ultrasound. I attended Liverpool University for both under graduate and post graduate studies. Since qualification in ultrasound in 1999 I have acquired a vast array of experience in both the NHS and Private sector. I currently work in a large NHS University Hospital Trust as well as the CQC registered manager here at First Choice Baby Scan.

As a dedicated professional I regularly lecture on the MSc Ultrasound courses at Liverpool University and St.Martin’s college, Lancaster. I gained my Fetal Medicine Foundation Certificate of Competence for performing 11-13+6/40 scans (Nuchal Translucency) in 2006, and have maintained my licence since. All the scans here at First Choice Baby Scan comply with the latest UK guidance / recommendations (NICE, NHS FASP, BMUS, FMF, RCOG, RCR) thus you have the peace of mind that as well as producing “pretty pictures” of your unborn baby we will also be performing a full diagnostic scan. I hope you will come and visit us at FIRST CHOICE BABY SCAN and have a unique, enjoyable experience.


If you are interested in a private ultrasound and would like to know what we offer why not visit our website today.


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