How do you know if you are pregnant with twins?

Are there twins in the family? Or are you really, really nauseous and tired and can't visit the gynaecologist for a first ultrasound for a few weeks? Then you're probably eager to find out whether there's one or two (or more?) babies in your belly.

The different types of twin pregnancies

Just a reminder: during fertilization, it can happen that two eggs are fertilized by two sperm: this is called twins. They can be of different sexes or of the same sex. They will have different physical characteristics, just like “classic” siblings. This is called fraternal twins.

Can you tell from the symptoms if you are pregnant with twins?

At the beginning of a multiple pregnancy (twins, triplets or more), the very first pregnancy symptoms are the same as with a so-called single pregnancy (with only one embryo): nausea, vomiting, absence of menstruation, changes in the areola of the breast, feeling of heaviness in the lower abdomen, shortness of breath, intense fatigue… In the case of a multiple pregnancy, these symptoms may be more intense, but that is certainly not always the case. So you cannot rely on symptoms to find out if you are pregnant with twins.

Is your belly bigger at the beginning of a twin pregnancy?

A big belly at the beginning of a pregnancy often suggests that it is a multiple. Sometimes it is the people around you who give you that hint: “It is definitely twins!”. Before 12 weeks, however, the embryos and the uterus are too small to conclude from the outside that there are two babies. Only after 12 weeks does the uterus become larger than in a 'normal' pregnancy with one baby.

In addition, mothers who are pregnant for the second or third time tend to have a larger belly more quickly, because the muscles stretch more quickly. Especially in women with a diastasis, the belly quickly appears 'pregnant'.

What are the hCG levels in twins or multiples?

The only real indication of a multiple pregnancy is the hCG levels in the blood. The pregnancy hormone appears in the blood 8 to 10 days after implantation, and doubles every two days in the first weeks of pregnancy. Low levels, or levels that do not increase exponentially, can indicate an impending miscarriage (although we prefer the word loss) or an ectopic pregnancy, and with noticeably high levels there is a chance that it is twins or multiples. The higher the levels, the more pronounced the pregnancy symptoms. That is why some twin mothers experience noticeably more pregnancy symptoms.

Please note that hCG levels are not enough to conclude that you are expecting two babies (or more). You can have high levels without being pregnant with twins, and pregnancy hormone levels do not tell you how many gestational sacs are in your uterus, whether there are (or will be) embryos in those sacs, or how many hearts are beating.

Ultrasound: the only way to detect a twin or multiple pregnancy

Only a vaginal ultrasound can tell you for sure whether you are pregnant with twins or not. However, an early ultrasound can 'miss' an embryo, especially if it develops a little slower than its brother or sister. The gynecologist will probably ask you to come back a few days later to be sure. From eight weeks of pregnancy, you are 100% sure how many hearts are beating.

Also read: Pregnancy calendar: your pregnancy week by week