But for geneticists, twin births are something to celebrate.

但对于遗传学家来说，双胞胎的出生是值得庆贺的。

But from 2014 to 2018, the twin birth rates fell 4 percent.

但在2014年至2018年，双胞胎出生率下降了4%。

Health experts say there is no single explanation for the falling twin birth rates.

健康专家表示，双胞胎出生率下降没有单一的解释。

He told The Associated Press that many people do not realize there can be serious risks with twin births.

他对美联社表示，许多人没有意识到双胞胎会带来严重的风险。

Although still rare, the dramatic increase in twin births can mean more negative health consequences for mothers of twins and her children, including premature births and low birth weight.

虽然仍然罕见，但双胞胎出生的显著增加可能导致母亲和孩子们承受更多负面健康后果，包括早产和出生体重过低。