I have acne-prone skin and on minocyclin medication. any effect on pregnancy?

Yes: You should not take any tetracycline while you are pregnant. It may discolor junior's teeth. Consider a topical agent such as Clindamycin in its place, or ask your physician whether you can take oral erythromycin.

Stop when pregnant: Minocycline and its close cousin Doxycycline should not be continued during pregnancy. There are a variety of acne medications that can be used safely during pregnancy and breastfeeding. Your dermatologist should be able to help you find a good regimen for you.