**5. Obstetric complications in twin pregnancy related to age**

There are not many studies specifically evaluating obstetric outcomes in twin pregnancies in advanced maternal age, and most of them are retrospective. These studies usually set the threshold for advanced maternal age at the "classic" 35 years, but in current times, this threshold should probably be reconsidered. A recent study by Zhu et al. [39] showed that, in twin pregnancies, advanced maternal age was associated with a higher risk of post-partum haemorrhage, gestational diabetes, and preterm delivery. However, other studies do not demonstrate any significantly increased risk over controls [40].

Much more attention has been paid to the obstetric complications in twins resulting from ART. Particularly, they are at increased risk of placenta praevia, caesarean section birth, preterm birth, and low birth weight [41]. Again, other studies showed no significant differences [42]. What we can be sure of is that twin pregnancies represent a huge demand for the body and that they do come with a higher obstetrical risk. Advanced age mothers' physical fitness necessarily cannot be the same to compensate for this fact.
