Congratulations! You're now halfway through your pregnancy and that 40 week due date (or even earlier if you're having twins or multiples, or are booked in for an assisted birth) is now firmly within sight. As exciting as it is that you're now over the halfway hump, it can also be quite an emotional time knowing that it won't be long until your baby arrives.

You might be having your anomaly scan this week which is a wonderful opportunity to see your baby, and find out the sex if you want to (and if Baby cooperates!). While your first ultrasound produced images of something that looked not much different to a peanut, you'll be truly amazed at how much your baby has changed when you see the new images on the screen.

Baby: What's Happening?

Once again, your baby has done some serious growing in the last week, and is now expected to weigh about 10.5 ounces. Based on your baby's measurements which will be taken during the scan (which should be about 6.5 inches from head to bottom, and then an extra 4 inches for the legs), your sonographer may be able to provide a more accurate weight.

Your baby is starting to swallow more and more of the amniotic fluid now, and the digestive system is working hard. This means that your baby's first "number 2" is bulking up. Known as meconium, this green/black sticky poop is likely to fill up your baby's first diaper nicely.

As the ultrasound will show, your baby is pretty much fully formed, and is just really putting on weight now ready for surviving in the outside world. The sonographer will be able to show you all the facial features, and they can be seen in such detail that the Doctor will be looking for evidence of a cleft lip or palate which may require surgery.

The sonographer will also be checking that all four chambers of the heart have formed and are functioning well, along with the kidneys and lungs. The size and shape of the brain will be looked at, along with the bones of the spine. The stomach and abdomen region is clearly visible, and the external limbs will be checked, although fingers and toes may be difficult to count because the pressure on your abdomen may mean Baby's squirming quite a bit!

The genetalia should be very evident, if you wanted to find out the sex. Some do, some don't. Your baby boy will have a developed penis and scrotum. Baby girls are more difficult to distinguish, so sonographers usually look for the absence of the penis, or for three lines that identify the vulva. Some babies are a bit camera shy and keep their bits well hidden, so you may not be able to find out if you're team pink or team blue until the birth.

You: What's Happening?

You may be feeling a bit nervous about going for your ultrasound, and it's completely normal but it's not necessary. The human body is very clever, and in most cases if there was something wrong with your baby your body would have let you know about it. If you've had a healthy pregnancy so far, the risk of any serious medical problems is very low.

The ultrasound will look at the position of your placenta. Most women will have a posterior placenta, that's one that has attached to the back wall of your uterus, and your baby has grown in front. Some women have an anterior placenta that has attached to the front wall, with the baby growing behind. Moms-to-be with anterior placentas usually don't feel their baby move as much, or as intensely, due to the placenta cushioning the blows.

In rare cases, women may have placenta previa; when the placenta attaches to the bottom of the uterus, with the baby growing above. Unfortunately it usually means a caesarean birth will be needed as the placenta is blocking the opening of the cervix. If you have placenta previa you may be offered more scans to keep an eye of the position. If the placenta remains in the same place, you may need to deliver earlier than expected due to the risk of bleeding. It's nothing to worry about, but it does need to be monitored.

The ultrasound itself is a safe procedure and shouldn't hurt. It may be quite uncomfortable though because the sonographer may need to press down quite hard on your abdomen to get a good look at your baby. Don't worry about that little guy or gal though, he or she is well protected by the amniotic sac.

Your uterus will have risen even higher up your abdomen now, and you can expect to feel the tip at roughly the same level as your navel. Measuring roughly 20 cm, or 7.5-8 inches, you're sure to be looking noticeably pregnant now.

Handy Hints

Aim to arrive at your ultrasound appointment with a full bladder. As difficult as it may be to refrain from using the bathroom, it's important to keep the bladder expanded as it gives a much better view through to the uterus. Don't go crazy though, you don't want to wet yourself! Try drinking between half a liter and one liter of water about an hour before your appointment time, and don't use the bathroom until after your appointment. If your bladder isn't full enough, you may be asked to have some fluids and come back later.