It depends on the stage of gestation. First trimester can be very high. It'll start to normalize in second trimester. Any dips and changes in the third trimester may be indicative of complications but even that's not always true. They're blood pressure changes just like ours does.
@krystim, at my first appointment the baby's bpm as at 170 and then the next one dropped to 165. it's pretty normal lol.. they actually say when the bpms high "it's a girl"!!!!