Coffee, once basely denigrated by doctors, is now back in their pharmaceutical good graces: as long as its not mixed with tobacco or alcohol, it seems to promote good cardiovascular health, have numerous antioxidant properties, and also improve brain function. So it is that, almost every month, we see a generous helping of articles extolling the merits of the miracle drink, brought into being on a dull day on the high Ethiopian plateaus. Yet, in the treatment information, where all the great gurus of medicine now agree to prescribe coffee in dozens of daily cups, unfortunately, there still exist, in bold type, a sorry list of warnings, occasioning a thousand torments in the thrice-cursed souls concerned – a group that includes pregnant women.

Recent studies have shown that merrily knocking back coffee may harm liver development in foetuses. We do not know if this warning is also valid for tea … To the (unbearable) pangs of labour, must be added abstention from some of the good things of life during the long period of pregnancy, and when we make these comparative observations, the concept of equality becomes a poor joke.
https://www.mirror.co.uk/science/drinking-much-coffee-during-pregnancy-18769847