The only definite way to find out whether you're having twins or other multiples is to have an ultrasound scan. The best time to have this ultrasound is at 10-12 weeks of pregnancy. This is usually when your health professional can say for sure how many fetuses, placentas and amniotic sacs there are.
How soon can you tell you're pregnant with twins? Your doctor won't be able to tell for sure until your first trimester ultrasound, which is usually done between 6 and 9 weeks of pregnancy but can be done any time between week 14.
If your twins are fraternal — meaning, two different eggs were fertilized — there will be a separate gestational sac for each baby. If you're estimating your pregnancy accurately, multiple sacs should be pretty visible on a transvaginal ultrasound at 7 weeks.
While any fetus at 5 weeks is still tiny, ultrasounds can still find the gestational sacs in the uterus, meaning it's possible to find out you have twins this early!
Seeing twins at 6 weeks is definitely possible. The exact time twins can be detected depends on the type of twins, for example, if they're identical (from one egg) or not. At this stage, the presence of two yolk sacs can be seen, and separate heartbeats distinguished.
Splitting of the embryo may occur at any time during the first 2 weeks after fertilization, resulting in several forms of monozygotic twins.
Early signs of a twin pregnancy include severe morning sickness, quick weight gain, and more breast tenderness. You may also notice an increased appetite or extreme fatigue. Plus, those who have a twin pregnancy may begin showing sooner.
By the time you're four weeks pregnant, your twins will each be about the size of a poppy seed. Their hearts will begin to beat in the next week, pumping blood throughout their tiny bodies. Even at this early stage, vital parts of your twins' nervous systems are already developing.
Twin baby development at 8 weeks
You can see them both on ultrasound now and your provider can detect heart beats. Their cells have been multiplying and are differentiating into different body systems and body parts, and their organs are forming rapidly.
The baby's heartbeat can't usually be detected before about 7-8 weeks, but some scans are performed before this. If one of the tiny twins happens to be hidden behind the other when the scan is performed, then there might not be any clue that you're carrying more than one baby.
If you have a transvaginal ultrasound at 6 or 7 weeks, you might only see one baby when there's really two. Your twins share an amniotic sac. Sometimes twins develop their own individual sacs, but when they share one, it increases the likelihood that one twin could be hiding during an early ultrasound.
Home pregnancy test positive earlier than “normal”
If you get a positive test, especially a really dark positive, days before your period is even due, that may be one of the early signs of twins! The more babies you're carrying, the higher and faster your human chorionic gonadotropin hormone (hCG) rises.
Sometimes, they may be found earlier, especially if your uterus is growing much faster and larger than normal.
Range of hCG levels and what they can mean
The range for singletons is 5 – 397 and for twins it is 48 – 683. As you can see, there is a big overlap between the first hCG level in singleton and twins.
#1 Fraternal twins can be conceived as much as 24 days apart
For this reason, fraternal twins can be conceived a few weeks apart, though they generally will be born at the same time.
At this stage, the only things you'll likely see are the yolk sac and the gestational sac. It's possible that the sonographer might be able to point out the embryo, which at this stage is likely a tiny white curled object. Surrounding the embryo is the yolk sac, which will look like a small white circle.
Your Twin Babies at 6 Weeks Pregnant
Right now, the developing embryos are about a quarter of an inch long, or the size of a sweet pea. This is the week where the head starts to develop, with dark spots where your babies beautiful eyes will form, and tiny little depressions where ears and nose are going to grow.
Their skin is paper-thin, and their veins are clearly visible. Their arm and leg buds are still growing and have started to form wrists, and webbed fingers and toes. There's a lot going on with your twins' faces too.
For now, you'll see a little figure that looks something like an oblong bean. If there are twins, you might see two figures. The head is still nearly the same size as the rest of the body. You'll also see the gestational sac, the fluid-filled space around your baby(s).
Two Babies Are Visible on an Ultrasound
This peek into the womb can clearly show the presence of two fetuses, or even two embryos early in the pregnancy. In the past, ultrasound scans could potentially miss a twin pregnancy, for example, if two embryos were close together and one embryo was obscuring the other.
3 WEEKS: Twins implantation
Each baby grows from a separate fertilized egg (zygote). Each has their own placenta and amniotic sac.
It is estimated that 1 in 250 natural pregnancies will naturally result in twins. While twin pregnancies can happen by chance, there are some factors that may increase your odds of having two babies at the same time. Let's learn about twins!