I had terribly itchy legs towards the end of my pregnancy,waking me up in the night,it was awful.Blood pressure & urine were fine at midwife appointment,just happened to mention itching,was sent for a scan & blood tests the next day,to find I had a rare form of pre-eclampsia,was immediately induced & gave birth to a healthy baby girl 10 hours later,I was quite poorly though & was on high-dependency unit for a while.
So my advice would be to tell your midwife everything no matter how small,as it could make all the difference.