An Australian woman who was told she might never become pregnant says she has given birth to twins conceived 10 days apart.
一名称自己可能怀孕无望的澳洲女子，产下一对相隔10天受孕的双胞胎。
Kate Hill was receiving hormone treatment for polycystic ovary syndrome, a condition that meant she was not ovulating.
这位名叫凯特.希尔的女子患有多囊性卵巢综合征，不能排卵怀孕，她为此接受激素治疗。
She apparently conceived twins at different times despite only having unprotected sex once during that time.
尽管那段时间她只进行过一次无保护措施的性行为，却在不同的时间里怀上了双胞胎。
It is very rare for a woman to conceive a second time when already pregnant.
一个已经怀孕的女性再次怀孕，是非常罕见的。
Most twins are the result of a woman releasing two eggs at the same time, or, less commonly, a fertilised egg subsequently splitting into two.
大多数双胞胎都是女性同时排下两颗卵子而来的，或者，也有少数情况是一颗受精卵分裂成两颗。
The twin girls, Charlotte and Olivia, were born 10 months ago with different sizes, weights and gestational development, according to reports.
报道称，双胞胎女孩夏洛特和奥利维亚已经十个月大了，她们出生时身高、体重和发育状况各不相同。
"We actually did not realise how special that was until they were born," Mrs Hill told Australia’s Seven Network.
希尔女士在接受澳大利亚《第七频道》采访时说，“直到孩子们出生，我们才意识到这是多么的特别。”
Pregnancy normally stops the monthly cycle of ovulation but very rarely a woman can release another egg after conceiving. If this is fertilised it could also implant and develop into a healthy pregnancy.
一般情况下，女性怀孕后就停止排卵，但极为罕见的是，如果在怀孕后还能排卵，并且能正常受精，也能着床并发育成一个健康的胚胎。
It is believed only 10 cases of the phenomenon, known as superfetation, have been documented across the world.
这种情况在医学上被称作异期复孕，极为罕见，据估计全球只有10例记录在册。
Speaking about the rare conception, Mrs Hill’s husband Peter joked: "Hole in one, maybe."
谈到这一罕见的怀孕，希尔的丈夫皮特开玩笑道：“可能是一击入洞。”
The couple’s obstetrician Brad Armstrong said the condition was so rare he was forced to search for it online.
这对夫妻的产科医师布莱德.阿姆斯特朗称，这一情况十分罕见，他不得不上网查找。
"I could not find any literature in the medical review websites at all," he said.
他说，“我在医学综述网站上找不到任何文献资料。”
