All births are a beautiful miracle, but there is a special excitement (and worry) that comes with news of twins. Eager parents who were making wish lists and dreaming of life with a new baby now have twice the fun to look forward to. In some rare cases, however, the stress can begin long before birth. 

Sarah Thistlethwaite was surprised to hear that she was pregnant with twins. What's more, she had monoamniotic-monochorionic twins, or "mono-mono" twins. Only occurring in one out of 10,000 pregnancies, her identical twin babies shared a placenta and an amnionic sac. While people may joke that twins are constantly together, most twins develop in their own amnionic sacs and are separated in the womb. These two would actually be in constant contact with each other. 

As endearing as it sounds, mono-mono twins present many potentially fatal risks during pregnancy. The shared placenta may become compressed, restricting the amount of nutrients given to each fetus. One baby may take more nutrition than the other, resulting in the death of the other twin. With a shared sac, umbilical cords can become entangled. There is no treatment, and the only recommended course of action is aggressive fetal monitoring. 

Despite the associated risks of pre-term delivery, mono-mono twins are at such risk in utero, they are all scheduled for C-section delivery at 34 weeks gestation. Most face complications as early as 26 weeks, leading to emergency cesarians. Sarah's delivery is noteworthy in that she was able to have Jillian and Jenna without any complications. Truly a Mother's Day Miracle. 

SF Globe wishes them the best in their new life as a family of five. Let us know what you thought of this story or if you have any great twin birth stories to share.