Twins on Ultrasound During Pregnancy: FAQS



Even if you’ve had children before, the differences that come with having twins can be vast, so it’s helpful to do some research along the way. Here at Take A Peek, we’ve been assisting to-be parents with 2D 3D and 4D ultrasound scans for over a decade now, so we thought we’d impart some advice regarding having twins, and seeing them on an ultrasound scan during your pregnancy.

Here are our top FAQs when it comes to having twins and how the 3D or 4D ultrasound scan may be affected by this.

When is the best time to come for a 4D scan with twins?

The best time to come is around 26 weeks, when the babes are starting to put weight on. It is better to scan them earlier than the 30 week we recommend for a single baby, as with twins, they get rather squashed up in there after around 28 weeks.

When will I be able to see that I’m having twins on an ultrasound scan?

You will be able to see twins on a 2D dating scan from as early as 7 weeks here at Take A Peek . We will be able to see if the babies are in their own sac or share a sac. At this stage we will be able to detect their heartbeats, measure them and show you the heart flickering away on the screen

Will I Be Able To Tell From The Ultrasound Whether My Twins Are Identical or Non-Identical (Fraterna)l?

The general rule to identifying if you are having non-identical twins is whether they have their own individual placentas. If so, it is unlikely that they will be identical, but in some cases, it can be deceiving.

Fraternal Twins (non-identical twins) usually occur when two fertilised eggs are implanted in the uterine wall at the same time which then become fertilized by two different sperm. The two eggs form two zygotes. and these twins are therefore also known as dizygotic. Dizygotic twins, like any siblings. have a very small chance of having the exact same chromosome profile; but most likely have a number of different chromosomes that distinguish them. Dizygotic twins may be a different sex or the same sex, just as with any other siblings. Like singleton siblings. they share 50% of their DNA.

Can Boy/Girl Twins Be Identical or Are They Always Fraternal?

You should naturally assume that if the genders of the twins are different, it’s almost definitely the case that they are non-identical – twins.

How Will I Know if There’s Any Risk of TTTS with My Twins?

TTTS – which stands for Twin-to-Twin Transfusion Syndrome – is where the placental supply of mono/mono twins is shared unevenly, which can mean that one twin is starved of nutrients and oxygen. Sharing the same amnion (or the same amnion and placenta) can cause complications in pregnancy. For example, the umbilical cords of monoamniotic twins can become entangled, reducing or interrupting the blood supply to the developing foetus. Monochorionic twins, sharing one placenta, usually also share the placental blood supply. These twins may develop such that blood passes disproportionately from one twin to the other through connecting blood vessels within their shared placenta. leading to twin-to-twin transfusion syndrome.

Your Take A Peek Sonographer will be able to detect this for you and refer you to a doctor if the syndrome is detected, though only 20% of mono/mono twins will actually develop this.

Contact us here at Take A Peek today to book in for your first 3D or 4D ultrasound scan in St Helens, Merseyside. We help expecting mothers in all surrounding areas, such as Wigan and Leigh, to discover whether they too will be having twins – during their pregnancy.

If you’ve any further questions regarding having an ultrasound and detecting twins, do not hesitate to get in touch with us. Our expert team are always happy to impart some guidance and help your pregnancy run as smoothly as possible.

As an independent scanning studio, you can be sure that your visit will be unrushed and booked in at the earliest convenience. As a team of three UK qualified Sonographer owners, we strive to create the best atmosphere for such a momentous occasion. We look forward to meeting you and your little bump.