Final answer:
The leading cause of pregnancy-related death during the first trimester is ectopic pregnancy, which is when the embryo implants outside the uterus, potentially causing significant internal bleeding.
Step-by-step explanation:
The question addresses the concern: What is the leading cause of pregnancy-related death during the first trimester? Among the options provided, a) Ectopic pregnancy is the most likely cause. Ectopic pregnancies occur when the embryo implants outside the uterus, commonly in the fallopian tubes, which can lead to significant internal bleeding and, if left untreated, can be life-threatening.
An ectopic pregnancy can happen due to scar tissue in the fallopian tubes from a previous infection or other factors that prevent the embryo from reaching the uterus. If detected early, treatment might involve medication such as methotrexate. Late diagnosis, however, especially if the tube has ruptured, usually necessitates surgical intervention. This is why ectopic pregnancy is a critical condition to identify and manage in the earliest stages of pregnancy.