The answer to this question hinges on the meaning of "children".  In the Bible, "children" or "sons" (depending on the text in question) is used in two distinct ways:

 - Literal biological descendants (obviously), eg, Deut 24:16, Eze 18, etc.
 - Metaphoric descendants indicating people who have the the same attitudes and disposition

It is the second category that is clearly in view in Matt 27:25.  Here are more example of metaphoric "children" or "sons"

 - 1 John 3:9, Anyone born of God refuses to practice sin, because God’s seed abides in him; he cannot go on sinning, because he has been **born of God**
 - 1 John 4:7, Beloved, let us love one another, because love comes from God. Everyone who loves has been **born of God** and knows God
 - 1 John 5:1, 2, Everyone who believes that Jesus is the Christ **has been born of God**, and everyone who loves the Father also loves those born of Him. By this we know that we love the children of God: when we love God and keep His commandments.
 - 1 John 3:10, By this the **children of God** are distinguished from the **children of the devil**: Anyone who does not practice righteousness is not of God, nor is anyone who does not love his brother.
 - John 8:44, You belong to **your father, the devil**, and you want to carry out his desires. He was a murderer from the beginning, refusing to uphold the truth, because there is no truth in him.
 - Acts 13:10, and said, “O **child of the devil** and enemy of all righteousness, you are full of all kinds of deceit and trickery! Will you never stop perverting the straight ways of the Lord?
 - Rom 9:8, So it is not the children of the flesh who are God’s children, but it is the **children of the promise** who are regarded as offspring.

Thus, Matt 27:25 is discussing those who agree with those who agitated for Christ's crucifixion - unbelievers who refuse to accept Jesus sacrifice of atonement for our sins are also guilty of His crucifixion.

 - 1 Cor 11;27, Therefore, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of sinning against the body and blood of the Lord.
 - Acts 5:28, “We gave you strict orders not to teach in this name,” he said. “Yet you have filled Jerusalem with your teaching and are determined to make us responsible for this man’s blood.”
 - Matt 23:35, so that on you may come all the righteous blood shed on earth, from the blood of righteous Abel to the blood of Zechariah the son of Barachiah, whom you murdered between the sanctuary and the altar.
 - Heb 10:29, How much more severely do you think one deserves to be punished who has trampled on the Son of God, profaned the blood of the covenant that sanctified him, and insulted the Spirit of grace?

IMPORTANT NOTE

I do not believe that the curse that the Jewish leadership called upon themselves in Matt 27:25 means that all Jews are subsequently cursed.  The reason is simple - many Jews were NOT present and many Jews have subsequently become Christians.  It is only those (whether Jews or otherwise) who refuse to accept Jesus as Messiah that fall victim to the the curse.

This was played out less than 40 years after this curse was pronounced.  In the destruction of Jerusalem in 70 AD, perhaps as many as one million Jews perished.  Christians escaped the city, precisely because they recalled the warning Jesus, and escaped destruction.