Must one divorce his wife if he has been married for 10 years without kids?
If one has already been married for ten years and has not yet fulfilled the Mitzvah of Peru Urevu, then from the letter of the law, the couple must get divorced and are forced to do so by the Beis Din. Nevertheless, the old age custom of several generations is not to be particular about matches, and hence we no longer force such a couple to get divorced.
A Maaseh Shehaya:
The curious Bochurim followed the Rebbe’s car to see where it would be heading. You see, in the early years the Rebbe was accustomed to walk home after Davening, and when the Bochurim saw the Rebbe get into the car with his wife they knew that something was astray. After about 20 minutes of driving, the Rebbe’s car pulled up to a driveway in front of a home in the Williamsburg neighborhood. The Rebbe and Rebbetzin left the car and entered the house. After the passing of a considerable amount of time the Rebbe and Rebbetzin exited the house and returned to Crown Heights. The curious Bochurim, knowing no limits to help quench their curiosity, knocked on the door of the house to try to receive some hint as to what transpired in the home. A middle aged couple answered the door and asked how they can be of help. The Bochurim replied that they wanted to know as for what purpose the Rebbe visited their home. “Which Rebbe?” asked the couple. “The Lubavitcher Rebbe”, answered the Bochurim. “You mean that the couple who just visited my home was the Lubavitcher Rebbe and Rebbetzin?” asked the couple in astonishment. “Yes indeed it was,” replied the Bochurim, “and what is it that they told you?” Please come in and have a seat and we will explain. You see my wife and I are married for over ten years and we have not merited having children. We have thus seriously considered getting divorced, as is the ruling of the Shulchan Aruch. Today this respected couple came to our door, looking like a Rabbi and Rebbetzin, and persuaded us not to get divorced. The Rabbi explained that according to Halacha there is no need to get divorced today, and that even he and his wife are married for more than ten years without children, and they still remain married despite the letter of the law. The couple convinced us not to get divorced, and now I see that it was none other than the Lubavitcher Rebbe and his wife who came to visit us. All those present were left in astonishment seeing the Rebbe’s and Rebbetzin’s care for a couple they did not know, and how they troubled themselves to meet with them to help save their marriage.
 Rama 1/3; Rivash 15
 Heard from Rav S.Z. Labkowski, R.Y. of central T.T. Yeshiva N.Y.