The current law, passed in 1967, permitted abortion only until a fetus was "viable", which was assumed to be at 28 weeks.

现行的相关法律颁布于1967年，规定只有在胎儿能成型存活，相当于28周孕期以后才可以终止妊娠。

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To cause the expulsion of(an embryo or fetus)before it is viable.

胚胎学：研究胚胎和胎儿的形成和发育的学科。

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Wade, abortions are generally permitted until the fetus is considered viable, or able to live outside the womb.

CNN: North Dakota governor signs law banning most abortions