Multiple birth rates in Europe vary from 9 per 1000 to 20 per 1000 pregnancies. Midwives and doctors treat multiple pregnancies as high-risk because amongst other things they place additional strain on the mother. Women expecting more than one baby normally go more frequently to antenatal care check-ups to be able to detect any complication as quickly as possible. Multiple pregnancies are generally associated with a higher risk of preterm birth. A healthy diet and lifestyle and reduction of stress particularly during the final trimester are recommended.
The level of care required in a twin pregnancy and the decision as to whether a normal delivery will be possible depends, among other things, on whether the babies are sharing a placenta.
It is best for the babies if they both have their own amniotic sac and placenta. In this case, few complications should arise during the pregnancy, and a normal delivery can be possible. In some very rare cases, however, the babies share one amniotic sac and placenta. In this case, they normally must be delivered by caesarean section. The most complicated cases are those in which each baby has an own amniotic sac but they share a single placenta. Sometimes, one of the babies will develop faster than the other. This is referred to as "twin-to-twin transfusion syndrome". Specific treatment is required to redress the imbalance in this case.
An ultrasound scan during the first trimester is hugely helpful in classifying multiple pregnancies into these different categories. It is not always possible to determine with certainty whether twins are monozygotic or dizygotic, but this has no impact on how the pregnancy will progress or how the delivery will be managed.