This happened to a friend of mine, Tina, awhile back. Relevant background: Tina is of Indian heritage, but moved to our predominantly white country as a young teenager. Her husband is also an Indian raised here, and both choose to dress the "western" way most of the time and in terms of speech and mannerisms I'd probably assume they were both born and raised here if I didn't know otherwise.
At a social setting she went to with friends (so her husband wasn't there) Tina was asked by a lady "So, I guess you must have had a C-section?" As it happened, Tina had (due to complications her twins were delivered at 8 months via c-section) and so she said yes. The lady went on to comment about how this is why inter-racial coupling was such a bad idea because it causes issues with childbirth. Now, I'm no doctor, but that sounds like a racist myth to me.
Tina was gobsmacked. This lady assumed Tina's husband is a different race to her, and then assumed that she must have had to have a c-section because of it. Tina didn't know where to start with correcting her! Probably would be a waste of time with somebody so presumptuous.
Incidently, this woman is actually a midwife, so I would think that she should know better than to spout such rubbish. I hope this isn't what they teach at the midwife training she went to!