Re: pregnancy when having port wine stain?
Estrogen is elevated during pregnancy. Estrogen causes blood vessels to enlarge. Your blood vessels are already enlarged where your birthmark is. So, they usually get darker, thicker and can become painful during pregnancy as they press on nerves from new, deep tissue growth. We highly recommend NO HORMONE therapy for women with large vascular birthmarks or thick ones as the "pill" will also cause the same result. Again, depending on the size and depth of your lesion, you may or may not have problems but be cautioned about hormones and puberty, pregnancy, and menopause.