Gemara

(Rav): Yesh Chupah l'Pesulos (Chupah takes effect even if she is forbidden to him).

(Shmuel): Ein Chupah l'Pesulos (it does not take effect).

(Rav Amram) Yesh Chupah l'Pesulos. A Mishnah supports this.

(Mishnah): (A Sotah answers) "Amen" that she was not Mezaneh when Mekudeshes, Nesu'ah, Shomeres Yavam (when awaiting Yibum), or after Yibum.

We cannot say that he warned her and took her to drink during Eirusin, for an Arusah does not drink;

If he warned her and she was secluded during Eirusin, and he took her to drink after Nisu'in, the water would not test her (for Nisu'in was forbidden after seclusion)! "The man will be clean from sin" - the water tests her only if he is clean from sin!

Rather, he warned her and she was secluded during Eirusin, and he had Chupah without Bi'ah. This teaches that Chupah takes effect on Pesulos.

Kesuvos 56a - Question (Ravin): If there was Chupah but no Bi'ah, does she receive the Tosefes?

Does Chivas (the dearness of) Chupah acquire?

Or, does Chivas Bi'ah acquire?

Answer (Rav Yosef's Beraisa): He wrote the Tosefes only for the Chivah of the first night.

This shows that Chivas Chupah acquires, for it is only on the first night. Chivas Bi'ah is even after the first night!

Question (Rav Ashi): If you will say that Chivas Chupah acquires, if she entered Chupah and became Nidah, what is the law?

If Chivas Chupah acquires, this is only a Chupah fitting for Bi'ah;

Or, perhaps we do not distinguish!

The question is unsettled.

Rishonim

Rif (Kesuvos 22b): Rav Ashi's question was not answered. Therefore, Chupas Nidah does not acquire.

Rambam (Hilchos Ishus 10:2): Once an Arusah enters the Chupah, her husband may have Bi'ah with her at any time and she is his full wife in every respect. She is called Nesu'ah even before Bi'ah, as long as Bi'ah was permitted. If she was Nidah, even if she entered the Chupah and was secluded with him, Nisu'in was not finished and she is still an Arusah.

Magid Mishneh: The Gemara asked whether or not Chupas Nidah acquires regarding (Tosefes) Kesuvah. The Rif says that since the question was not answered, it does not acquire. The Rambam and some Ge'onim explain that it does not acquire for anything, e.g. inheritance or Tum'ah. Some say that the question was only about Kesuvah, but it acquires for everything else.

Question #1 (Ran DH u'Pirsah): The Rif did not specify. It seems that he holds like the Rambam, who says that Chupas Nidah does not acquire at all. This is difficult. We hold that Yesh Chupah l'Pesulos (Yevamos 57b)! Rather, the question was only about Tosefes.

Answer #1 (Lechem Mishneh): Yesh Chupah l'Pesulos when he intends to have Bi'ah in spite of the Isur. In Yevamos; he marries a woman permanently forbidden to him, intending to have Bi'ah with her b'Isur. In Kesuvos we discuss one who will not transgress. A support for this is the Ri (brought in Hagahos Ashri 5:6), who says that Chupas Nidah acquires if he was aware that she is Nidah.

Question #2 (Lechem Mishneh DH Aval): Here the Rambam explains like Tosfos, that the Gemara (Yevamos 57b) discusses Chupah after Kidushin. In Hilchos Terumos (7:21), he explains like Rashi that it discusses Chupah without prior Kidushin, according to Rav Huna who says that Chupah itself makes Kidushin! In Perek 3 of Ishus, the Rambam does not say that Chupah makes Kidushin!

Answer (and Answer #2 to Question #1 - Lechem Mishneh): The Rambam did not want to say that Rav and Shmuel are unlike the Halachah. Therefore, he explains that even though Chupah by itself does not acquire, it can forbid. We find that Zikah to Yibum forbids eating Terumah, even though it does not permit.

Rosh (Kesuvos 5:6): After we settled that Chivas Chupah acquires the Tosefes, Rav Ashi asked about Chupas Nidah. R. Chananel and the Rif rule that it does not acquire. The Rambam explains that Rav Ashi asked whether or not Chupas Nidah is considered Chupah at all. This is difficult. If so, why did he ask here? He could have asked about any Mishnah that discusses Chupah, e.g. a Bas Yisrael does not eat Terumah before Chupah! Rather, clearly it is Chupah, and he asks only about Tosefes. The initial reasoning was that Chivas Bi'ah acquires. We showed that Chivas Chupah acquires, but it is reasonable that this is only if Bi'ah was permitted.

Poskim

Shulchan Aruch (EH 61:1): Once a man enters his Arusah to Chupah, even if they did not have Bi'ah, she is his full wife in every respect. She collects the Ikar Kesuvah and the Tosefes if she is widowed or divorced. This is if Bi'ah was permitted. If she was Nidah and then entered the Chupah and was secluded with him, she is not his (Nesu'ah) wife. She is still an Arusah because she was Nidah.

Chelkas Mechokek (1): The Mordechai says that if she became Nidah during the Chupah, there is no more Chivas Bi'ah (and he does not acquire her). This is difficult. Once he acquired her at the beginning, how does his Kinyan lapse?! Perhaps he holds that the end of Chupah acquires, and Bi'ah begins after the end of Chupah. The Kinyan is not finished until Bi'ah or until the seven days of Mishteh are finished. The Mordechai also says that if she became Nidah not at the time of her Veses, it is his bad fortune (and she collects her full Kesuvah). This is difficult. We said so (Kesuvos 2b) only according to the opinion that he feeds her if an Ones such as sickness delays the Chupah. We conclude that he does not feed her when there is an Ones. All the more so she does not get Tosefes. He wrote it only on condition that there will be a Chupah fitting for Bi'ah! It seems that the Mordechai obligates Tosefes (if she became Nidah not at the time of her Veses) only if she was Tehorah at the beginning of the Chupah.

Shulchan Aruch (ibid.): Some say that this is only regarding collecting Tosefes, but in every other respect she is like a Nesu'ah.

Question (Chelkas Mechokek 2): Once the time set for Chupah comes or she is given to her husband's Sheluchim he must feed her, and he receives all privileges in a Nesu'ah (earnings, Metzi'os, Peros and inheritance)! We must say that this is only if she is fitting for Bi'ah. Mesirah to his Sheluchim is no better than Chupah, which does not make her a Nesu'ah (according to the Rambam for all of these matters) if she is Nidah. However, the Rambam is difficult. Rav Ashi said 'if you will say that...', which implies that his question depends on the previous question! In a Teshuvah (54:2) the Rosh says that Chupah with a deathly sick woman is not a Chupah, for she cannot have Bi'ah, so he does not inherit her. This is like the Rambam. In his Pesakim the Rosh retracted and said that the question is only regarding Tosefes.