It is generally safe to drink pineapple juice while pregnant as long as it is consumed in moderation and you do not have gestational diabetes or gastrointestinal issues like acid reflux or diarrhea from pineapple. Pineapple contains an enzyme called bromelain, which has been rumored to cause contractions or miscarriage, but the amount found in the fruit's flesh or juice is too low to pose such risks. Drinking pineapple juice can provide beneficial nutrients such as vitamin C and hydration, but excessive consumption should be avoided to prevent digestive discomfort or other minor risks. It is also recommended to avoid the core of the pineapple, which has higher bromelain levels. Always consult with a healthcare provider for personalized advice during pregnancy.