The sudden natural end of an unborn child before it can survive outside the womb. Miscarriage happens in both animal and human pregnancies (Genesis 31:38; Job 3:16; 21:10; Hosea 9:14). The main problem is not the inability to become pregnant but the difficulty in carrying the pregnancy to full term. The curse of a "miscarrying womb" means a woman cannot have children (Hosea 9:14). The blessing of God results in successful pregnancies and long life (Exodus 23:26).
The key issue in miscarriage is timing, shown by early delivery or what the Bible calls an “untimely birth” (Psalm 58:8; Job 3:16). Although miscarriages happen for many reasons, the Bible mentions two specific causes:
poor care of pregnant animals (Genesis 31:38), and
physical injury to a pregnant woman (Exodus 21:22).
Numbers 5 describes a test for a wife suspected of being unfaithful. If she is guilty of adultery, “her belly will swell, her thigh will shrivel” (Numbers 5:27). These phrases might be ways of describing either a miscarriage or the inability to have children.
The apostle Paul emphasizes his unworthiness to be an apostle by comparing his spiritual birth to a premature physical birth (1 Corinthians 15:8).