He was told that his wife had revived a previous forbidden relationship so he divorced her
Question

                My friend got divorced in this Ramzan and his wife was(is) 5 months pregnant as well  .

The reason for divorce was that his wife had boy friends before marriage and someone said that after marriage also she would meet her ex boy friends .

On this reason he divorced her and under the influence of his parents.

Now what i want to know is was that a right path , did it have Allah's Sanction to this deed ? 

what about the child who is in the womb ? What will happen to that baby and his/her future ?
Praise be to Allah.
    What you have mentioned in the question covers a number of 
    issues: 

    1 – What you have mentioned about your friend divorcing his 
    wife during her pregnancy is valid according to the consensus of the 
    scholars, because of the hadeeth of Ibn ‘Umar in al-Saheehayn, 
    according to which the Prophet  (peace and blessings of Allaah be upon 
    him) said: “Tell him to take her back, then to divorce her when she is pure 
    (not menstruating) or pregnant.” That indicates that whoever divorces (his 
    wife when she is) pregnant, the divorce is valid. (Fataawa al-Talaaq 
    by Ibn Baaz, 1/45). 

    2 – With regard to the reason that led him to divorce her, 
    which is that person telling him that she had been meeting with her former 
    boyfriend after marriage, we advise those who want to pass things on to make 
    sure that any news is true before they pass it on, and that their intentions 
    are good. Her husband too should have checked whether what he was told was 
    true or not, and not divorce her on these grounds without verifying 
    anything. Allaah says (interpretation of the meaning): 

    “O you who believe! If a Faasiq (liar — evil person) comes 
    to you with any news, verify it, lest you should harm people in ignorance, 
    and afterwards you become regretful for what you have done”

    [al-Hujuraat 49:6]

    Hastening to divorce one’s wife without verifying anything 
    and without giving oneself time to think it over is a rejection of the 
    blessing of marriage for no valid reason and destroying the family which is 
    a blessing that Allaah has bestowed upon the children of Adam, as Allaah 
    says (interpretation of the meaning): 

    “And among His Signs is this, that He created for you 
    wives from among yourselves, that you may find repose in them, and He has 
    put between you affection and mercy. Verily, in that are indeed signs for a 
    people who reflect” [al-Room 30:21]

    If he finds out that something displeasing is true, then he 
    may try to correct it through the means which he is permitted to use by 
    virtue of his being in charge of his wife (qiwaamah), or he may 
    separate from her, whilst also concealing her sin. 

    3 – If the wife had previous relationships, before marriage, 
    then she got married and repented to Allaah, and broke off all forbidden 
    relationships, then she should not be rebuked for what is in the past, 
    because the one who has repented from a sin is like one who has never 
    sinned. Allaah says (interpretation of the meaning): 

    “And He it is Who accepts repentance from His slaves, and 
    forgives sins” [al-Shoora 42:25]

    It is not permissible to expose her, to tell everyone about 
    her or to call her to account for the past; rather he should cover up her 
    past and her secrets; whoever conceals the faults of a Muslim, Allaah will 
    cover his faults in this world and in the Hereafter. 

    Such cases explain to us the wisdom of the sharee’ah in 
    forbidding everything that may lead to an improper relationship between a 
    man and a woman, such as looking at a non-mahram woman, shaking hands with 
    her, being alone with her, and so on, whether that is before marriage or 
    afterwards. 

    4 – With regard to the husband’s parents applying pressure on 
    him to divorce her without any proof of the things of which she had been 
    accused, obedience to parents should only be with regard to that which is 
    good and proper, things that Allaah and His Messenger  (peace and 
    blessings of Allaah be upon him) have permitted. The Prophet  (peace and 
    blessings of Allaah be upon him) said: “Obedience is only with regard to 
    that which is good and proper.” (Narrated by al-Bukhaari, 7245; Muslim, 
    1840). His parents’ orders to hasten to divorce her with no proven sin on 
    the wife’s part is not something which is good and proper. 

    5 – With regard to the foetus in her womb, the basic 
    principle in sharee’ah is that that the child belongs to the (marriage-) bed 
    and belongs to the husband, unless he disowns him, because of the hadeeth of 
    the Prophet: ‘The child belongs to the (marriage-)bed and the adulterer is 
    to be stoned.” (al-Bukhaari, 2053; Muslim, 1457). 

    i.e., the child is to be attributed to the husband and no 
    attention is to be paid to doubts and the like, especially in a case like 
    this where the doubts are far-fetched. Islam encourages us to attribute 
    children to their fathers, so this husband should not open the door to 
    waswaas (whispers of the Shaytaan) with regard to his son who will be born 
    to the wife he has divorced, because he has no evidence to the contrary. 

    If this husband wants to go back to his wife after this 
    divorce (talaaq), if she is still pregnant and he issued the talaaq once or 
    twice, then she is still his wife according to sharee’ah, because her ‘iddah 
    has not yet ended. Allaah says: 

    “And for those who are pregnant (whether they are divorced 
    or their husbands are dead), their ‘Iddah (prescribed period) is until they 
    lay down their burden” [al-Talaaq 65:4]

    So he may take her back and ask two men to bear witness that 
    he is taking her back; in this way she will become his wife again.  

    But if she has already given birth and this was the first or 
    second talaaq, then he may go back to her with a new contract, so long as it 
    meets all the necessary conditions.  And he should beware of such news and 
    take care to protect his wife and keep her away from places which may give 
    rise to suspicion. And Allaah knows best.