Did the divorce occur once or twice, and is the wife's return to the husband's bond valid, taking into consideration that the husband pronounced divorce explicitly once, and another time linked it to the descent of a deformed fetus that did not show the creation of a human being?

The phrase "you are divorced" makes the divorce binding. As for the statement "it will be by three [divorces]," it does not effect anything if it is merely a promise of divorce, and there is no obligation to fulfill it. If it was intended as a contingent divorce, the majority of scholars hold that it takes effect when the condition is met. However, Ibn Taymiyyah holds that it does not take effect unless it was truly intended to bring about divorce; otherwise, an expiation for a broken oath (kaffarat yameen) is due. The majority of scholars hold that divorce pronounced with a single utterance counts as three divorces, whereas Ibn Taymiyyah holds that it counts as one divorce. The relied-upon opinion is that of the majority. If the major irrevocable divorce (baynunah kubra) has not occurred, and trustworthy scholars have given you a fatwa (definition) that the waiting period (iddah (definition)) has not ended with the miscarriage, then the return (raj'ah) is valid. Anger should be avoided.