What to expect when you’re expecting twins

At a global level, statistics say that twin or multiple pregnancies currently account for 3% of live births. So, if you’re wondering about your chances of having more than one baby at a time, the answer is simple: basically, your chance is about 3% or 1 in 33. Going further, the chance of having ‘natural’ fraternal twins is only about 1.7% or 1 in 60. The chance of having identical twins has remained steady, and is about 0.4% or 1 in 250. The chances of having twins with the use of fertility treatments can be as high as 20 to 25%.

As you’ve probably know, when we’re talking about a twin pregnancy, we may be talking about fraternal twins (also known as dizygotic or non-identical twins) and which are more common, accounting for two-thirds of all twins, and identical twins (monozygotic twins), which occur randomly and account for only one-third of all twins.

Fraternal (dizygotic or non-identical) twins usually occur when two separate eggs are fertilised by two separate sperms, resulting thus two separate embryos, each having its own individual characteristics as well as its own placenta and sac. This means that the non-identical twins are no more alike than any other two siblings, with different genetic heritage. The babies may be of the same sex or different sexes; half of all fraternal twins are boy-girl pair and the other half are same sex pair. Fraternal twins are more common for older mothers, with rates doubling over the age of 35. Fraternal twins occur in about 1 in 50 pregnancies.

Identical twins are sharing everything. They are the result of a single fertilized egg splitting into two separate embryos. The two embryos can share a single placenta and can be in the same or different sac. Since identical twins come from the same fertilized egg, they have the exact same DNA and consequently, the same sex, eye colour, hair colour and blood type. Furthermore, even if at birth, the babies have different heights and weights, as time passes by, their constitution will somehow become as similar as possible. Nevertheless, the environment that the twins are exposed to (in or out of the womb) determines fine physical characteristics. Therefore, identical twins usually have different fingerprints and as they get older, more differences generally develop.

However, statistics say that identical twins occur in about 1 in 250 pregnancies and this appears to be a random event rather than a hereditary trait, and is uniformly distributed in all populations around the world.

30 years ago, the mums-to-be usually found out that that they had been carrying more than one baby when they were ready to deliver. Now, things have changed: the first baby scan can tell you whether you’re expecting more than one baby. Therefore, if you haven’t had your first baby scan done, you are welcome to come to our London clinic where our highly qualified sonographer can confirm or infirm a single or multiple pregnancy.

There are also certain “signs” that may indicate a multiple pregnancy. So, you are more likely to become pregnant with twins naturally, when you are in your 30s and 40s since the chances of having twins increase with age. Also the likelihood of twins increases if: you took fertility medication or underwent other fertility treatments, or if you had a multiple pregnancy in the past because studies say that for the mothers who have already had one set of fraternal twins, their chances of conceiving another set are five times greater than the average woman, or if there is a family history of twins, or if you’re African-American woman because studies have shown that African-American women are more likely to have twins than any other race.

Women with twins may notice their pregnancy signs sooner or these signs may be more intense. This is because they have higher levels of both the human chorionic gonadotrophin (hCG) and the alpha-fetoprotein (protein released by the fetal liver and found in the mother’s blood) in their system. Other hormones increase during pregnancy as well, mainly progesterone and some oestrogen, which contribute to many of the early physical signs of pregnancy. The discovery you are expecting twins is often made quite early in pregnancy after you have a routine ultrasound scan. Two gestational sacs or foetuses are seen rather than one.
A twin pregnancy is sometimes suspected if the womb feels larger than expected to the doctor or midwife who examines you. Later in pregnancy, the two separate babies may be felt abdominally during an examination, and again this will be confirmed by ultrasound scan.

However, the safest confirmation occurs when your GP tells you that he/she’s hearing two heartbeats and, around the sixth week of pregnancy, the sonographer may see two little gestational sacs. Therefore, you are more than welcome to come to our clinic in the heart of London to find out together whether you’re expecting more than one baby and to prepare for and enjoy this wonderful journey.