In very rare cases, the implantation of a fertilized egg (blastocyst) occurs outside the uterus, thus causing a so-called ectopic pregnancy (Literally: out-of-place pregnancy.

• 在非常罕见的病例中，受精卵（胚泡）的植入发生在子宫（腔）以外，因而导致医学上称为异位妊娠的异常怀孕现象(照字面的意思：不在适当位置的妊娠。