Pregnancy scan Q&A’s answered by our expert

Do you want to find out the sex of your baby?

You do need to have a couple of blood tests during your pregnancy

Q: How accurate are dating scans? The expected date of delivery that the team gave me at the scan is almost a month after the due date I calculated from my menstrual cycle!

A: Dating scans are considered to be accurate to four to eight days, depending on when the scan is performed. The earlier in the pregnancy the scan is done, the more accurate the results. Most NHS hospitals offer women a dating scan between 10 and 14 weeks. Scans done later than this will still provide very good information but the expected delivery date may not be as accurate. It is important to remember that even when you are sure what date your baby is due, he may still arrive early or late. A baby is considered to be full term between 37 and 42 weeks’ gestation, and this is the time period when most babies will be born

Discrepancies in your dates and the scan dates may be due to you having a longer menstrual cycle or an irregular cycle. Women with a regular cycle do not always ovulate each month and there are a number of factors affecting the menstrual cycle. If women conceive as soon as they stop taking oral contraceptives or the injection, they may have a number of normal periods without having ovulated. If there are any concerns about the baby’s growth on the scan you will be offered further scans

Q: We can’t decide if we want to find out if our baby is going to be a boy or a girl – do you have any advice?

A: While many maternity units give parents an opportunity to find out the sex of their baby during an ultrasound scan, it is important to remember that the scan is primarily being offered to check on the baby’s development. This is a complex process and may be made more difficult if the baby is lying in an awkward position, so there may be occasions when the sonographer may not have the opportunity to identify the sex of the baby.

In some hospitals there’s a policy of not telling parents the sex, so you would need to check what your local unit offers. It may not be easy to identify the sex of the baby on scan and you may be told the wrong sex, although this is rare.

Think about why you might want to know the sex of the baby. Many parents choose not to know, because wondering about their baby helps them through the pregnancy and birth. Other parents are keen to know, as they feel it helps them to bond with their baby.

Q: I’ve just found out that I’m pregnant and, though it sounds silly, I’m really squeamish about the tests and scans I’ll have before I have my baby! What should I expect?

A: The purpose of antenatal screening is to monitor you and your baby, and all the tests are optional. There are a number of blood tests usually done in early pregnancy. Although there are a lot of tests, it is common to take just one lot of blood. Most women are offered two scans – the first to confirm the gestation of the pregnancy, and the second at around 20 weeks to look for anomalies. Scans are painless, although some women may feel uncomfortable due to a full bladder. The radiographer will ensure your privacy. During each appointment with your midwife, she will ask about you and the pregnancy, test your urine and check your blood pressure. She will also examine your abdomen to see how well the baby is growing. When you first meet with the midwife, explain to her how you feel. Understanding what is happening to you, and why, may make you feel better.

Q: I am 14 weeks pregnant and I am hardly showing – I am beginning to wonder whether a baby actually is growing in there! I’m so stressed out that I recently bought a Doppler instrument to reassure myself that there is a heartbeat, but I can’t find one. My next antenatal appointment isn’t for 5 weeks and I don’t know if I can wait that long. Please help!

A: At 14 weeks’ gestation, a foetus is approximately 5 – 7 mm in size, and while there are a number of other changes happening in your body, this is still quite small. Listening to the foetal heart is a skill which midwives have learned through three years of training. Due to the size of the foetus in the early weeks, it can be very hard to hear a heartbeat, even for experienced midwives, and this isn’t the only factor in assessing foetal wellbeing. Some women may be falsely reassured by a Doppler, while others may become more anxious if they cannot hear the heartbeat.

Women experience the changes of pregnancy differently – while some women may look pregnant early on, other may not. It depends on many factors and it is important to seek advice from your midwife or GP. There are other signs to consider too, such as skin changes, breast changes and sickness. The important thing is to see your midwife – you can bring your appointment forward.

Q: My partner and I are determined not to know the sex of our baby until he or she arrives. We’re worried though, that we might discover it by accident when looking at the scan. At what age is the baby’s sex visible, and what’s the danger of seeing it if we don’t want to?

A: Many hospitals do not routinely advise parents of the sex of their baby following a scan, as it is not always possible to see, particularly if the foetus is active or lying awkwardly. Most professionals would ask you before they told you but you should discuss your request with the midwife and remind the sonographer that you don’t wish to be informed of the sex at the beginning of your appointment. Your request could also be recorded in your maternity record so that anyone who cares for you will be aware of your wishes.

During pregnancy, the majority of women are offered ultrasound scans to assess the well-being and development of the foetus. Commonly women have their first scan around 10 weeks of pregnancy. The second is around 18 – 20 weeks of pregnancy. At this later stage of pregnancy, the baby’s organs are formed. This would be the most likely time that the sex of the foetus may be identified. Improved imaging on scans means that parents can often have a clear picture of their baby and it may be possible to determine the sex of the baby in some instances. However, the image is not easy to interpret and the sonographer will be able to take an image of your baby without you knowing the sex.