Twins used to be very rare and triplets or more were almost unheard of in the past. Although multiple births are still much less common than single births, they do happen much more often today. There are many reasons for this, including an increase in older mothers and improved medical care during pregnancy. The use of fertility treatment has also played a role, although the IVF today is less likely to produce multiples than it was in its early years. Many parents who undergo fertility treatment at the private fertility clinic in London would love to hear that they are expecting more than one baby, but multiple births are always riskier than single pregnancies, so IVF procedures are now designed to reduce the chances.
Multiple pregnancies can happen during IVF in much the same way as they do in an unassisted pregnancy. Fraternal twins can happen if more than one of the transferred embryos implants in your womb. This used to be very common as early IVF procedures often involved the transfer of many embryos, which could result in very high order multiple births. Conceiving fraternal twins through IVF is less common now because fewer embryos will be transferred. In many cases, just a single embryo will be transferred because it has a good chance of implanting successfully. Your doctor at the private fertility clinic in London may recommend a single embryo transfer if you are fairly young and a high-quality embryo has been produced by IVF.
However, there is another way in which twins can be produced even if you only undergo a single embryo transfer at the private fertility clinic in London. Sometimes an early embryo can split to produce two viable, genetically identical embryos. This can even happen when you already have two embryos implanted in your womb, which could leave you expecting a combination of identical and fraternal triplets or more.