How is it possible to reconcile the physicians' knowledge of the fetus's gender (male or female) with the Almighty's saying, "And He knows what is in the wombs," and the interpretation of Ibn Jarir from Mujahid and Qatadah? And what specifies the generality of the verse?

The explicit text of the Qur’an can never contradict reality. If a contradiction appears, then either the reality is merely an assertion, or the verse is not explicit in its opposition.

Knowing the gender of a fetus after its creation is not from the knowledge of the unseen (ghayb), because it has become from the knowledge of the seen (shahada).

Verse (34) of Surat Luqman indicates Allah's knowledge of the unseen regarding what is in the wombs before creation.

If the verse discusses masculinity and femininity after creation, then sensory perception and reality are the specificizers. If it does not discuss what is after creation, then there is no contradiction between it and knowing the gender of the fetus.

Scholars reconcile the indications of the Holy Qur'an with reality, for both are truth, and the explicit text of the Qur'an cannot contradict something known by observation.