In Hong Kong, as in much of the rest of the westernised world, when you learn you are pregnant, you take it for granted that you will follow a programme of antenatal visits. After the initial excitement it can feel that the checkups are a bit tedious and over-fussy, especially when all that the healthcare practitioner seems to do is check your weight, urine and blood pressure, but it is exactly these checks that provide the first indicators of a problem.