The Short Answer
A cesarean scar ectopic pregnancy with intrauterine pregnancy (O00.32) means one embryo implants inside the scar tissue from your prior C-section while a second embryo grows normally inside your uterus. This rare condition occurs in 1 in 2,000–5,000 pregnancies after cesarean delivery and requires urgent specialist care to protect both pregnancies [1].
After a cesarean delivery, the uterine scar tissue is thinner and less vascular than normal muscle. If an embryo implants into this weak scar instead of the main uterine cavity, it becomes a scar pregnancy. Federal ultrasound data show that scar pregnancies grow more slowly (beta-hCG doubling time >72 hours) and rarely develop a fetal heartbeat, whereas the intrauterine pregnancy follows normal growth curves [1].
Inside your body, the scar pregnancy sits in a precarious spot: the scar tissue cannot stretch or support a growing embryo the way normal uterine muscle can. As the scar pregnancy grows, it thins the uterine wall further, raising the risk of rupture and life-threatening bleeding. Meanwhile, your intrauterine pregnancy continues normally, competing for blood flow and space [1].
The real-world stakes are high but manageable with early diagnosis. If caught before 12 weeks on transvaginal ultrasound, your OB/GYN can choose from expectant monitoring, medical therapy (methotrexate), or surgical removal—each with different success rates for preserving your healthy pregnancy [2]. Waiting for symptoms like heavy bleeding or pain delays treatment and increases rupture risk.