A note in The Oxford Jewish Study Bible, which is based on the Jewish Publication Society Tanakh indicates that there is some disagreement between different manuscripts of the Masoretic Text. The JPS Tanakh reads:
Just as you do not know how the lifebreath passes into the limbs within the womb of the pregnant woman ...
which is similar to the ESV reading.
Apparently the Targum, which is older than the Masoretic Text, also includes this reading.
But the OJSB editors acknowledge that most manuscripts read like instead of into, which would be similar, for example, to the KJV:
As thou knowest not what is the way of the spirit, nor how the bones do grow in the womb of her that is with child: even so thou knowest not the works of God who maketh all.
Rashi's medieval Talmudic commentary also preserves this reading.
The Septuagint, also older than the Masoretic Text, also seems to agree with the majority Masoretic reading:
ἐν οἷς οὐκ ἔστιν γινώσκων τίς ἡ ὁδὸς τοῦ πνεύματος. ὡς ὀστᾶ ἐν γαστρὶ τῆς κυοφορούσης, οὕτως οὐ γνώσῃ τὰ ποιήματα τοῦ θεοῦ, ὅσα ποιήσει σὺν τὰ πάντα.
Among whom none knows what is the way of the wind: as the bones are hid in the womb of a pregnant woman, so thou shalt not know the works of God, even all things whatsoever he shall do.