Mid to Late Pregnancy Test for twins: Level II Ultrasound

Level II Ultrasound (also known as a fetal anatomy survey or scan)
This ultrasound is standard for all pregnancies (not just multiples) and is usually the 'big one' where you first get to learn your babies' genders. It is done when you are about 20 weeks along, but is usually repeated later in pregnancy if you are expecting multiples. My second level II ultrasounds were done around 30 weeks. This is done to assure that both babies are growing at a healthy rate and that intrauterine growth restriction, twin to twin transfusion syndrome (TTTS) or other complications are not affecting growth. With a singleton pregnancy, if mom’s belly is getting bigger, you can be quite assured that the baby is too. But with two inside, it is good to have more assurance that both babies are growing well and at a similar rate.
This ultrasound is essentially your babies’ first physical exam. The technician will take time to measure several different parts of baby’s body, including baby’s ‘crown to rump’ length (it’s hard to measure a baby’s total height when she’s all squished up in there!), head circumference, length of arms and legs and even of her little foot (which is a great measurement to keep track of and note or draw if you keep a pregnancy journal!) I actually asked the technician to simply print the screen on which she tracked all of my babies' measurements. Of course, you can learn the gender of your babies if you want, but be sure to let the technician know if you want to be surprised.
The technician (or sonographer) will also ‘examine’ some of babies’ major organs – kidneys, heart and brain. They do this to the extent that they examine each heart chamber, and identify the sections of her brain. They also view and measure the stomach. Suffice it to say that if they don’t find anything unusual, you probably have some very healthy babies in your big belly. Even if they do find something 'iffy' it is often resolved or more clearly normal at a later ultrasound.
If you see something you like, be sure to ask the technician to print a photo for you. Most technicians will give you a whole bunch of shots from the ultrasound, just be sure you check them before posting on your facebook profile, I found mine had my birth date, full name AND social security number embedded on them! So much for privacy…I wonder if they shred those when they are done?
Before your ultrasound, you may want to consider the following so you can be prepared. First, it takes about 45 minutes to do this detailed examination on just ONE baby. Add a second baby in there, and you could be in the ultrasound room for an hour and a half. Now consider that baby B will sometimes get in the way of a measurement they are trying to get on Baby A and now you could be in there for up to 2 hours! I recommend taking a potty break right before the exam (presuming you don’t need a full bladder as you do with earlier ultrasound exams). Also, you might bring a snack if it will be getting close to meal time.
This site "What to Expect", has some great info on ultrasounds and all pregnancy testing.