Here are a few more accounts on that practice (abortion),
On the seventeenth day of May, 1842, having been made acquainted with some of the conduct of John C. Bennett, which was given in testimony, under oath…by several females who testified that John C. Bennett endeavored to seduce them, and accomplished his designs by saying it was right; that it was one of the mysteries of God, which was to be revealed when the people was strong enough in faith to bear such mysteries — that it was perfectly right to have illicit intercourse with females, providing no one knew it but themselves, vehemently trying them from day to day, to yield to his passions, bringing witnesses of his own clan to testify that there were such revelations and such commandments, and that they were of God; also stating that he would be responsible for their sins, if there were any, and that he would give them medicine to produce abortions, provided they should become pregnant.” (History of the Church, 5:71)
"Did you ever hear of abortion being practiced in Nauvoo?"
"Yes. There was some talk about Joseph getting no issue from all the women he had intercourse with. Dr. Foster spoke to me about the fact. But I don't remember what was told about abortion. If I heard things of the kind, I didn't believe in them at that time. Joseph was very free in his talk about his women. He told me one day of a certain girl and remarked, that she had given him more pleasure than any girl he had ever enjoyed. I told him it was horrible to talk like this." (Interview with Wm. Law. March. 30, 1887; THE DAILY TRIBUNE: SALT LAKE CITY, SUNDAY MORNING, JULY 31, 1887.)
Mrs. [Sarah Pratt].: "You hear often that Joseph had no polygamous offspring. The reason of this is very simple. Abortion was practiced on a large scale in Nauvoo. Dr. John C. Bennett, the evil genius of Joseph, brought this abomination into a scientific system. He showed to my husband and me the instruments with which he used to * operate for Joseph. ' There was a house in Nauvoo, 'right across the flat,' about a mile and a-half from the town, a kind of hospital. They sent the women there, when they showed signs of celestial consequences. Abortion was practiced regularly in this house."
Mrs. H.: "Many little bodies of new-born children floated down the Mississippi..."
May 21, 1886, I had a fresh interview with Mrs. Sarah M. Pratt, who had the kindness to give me the following testimony additional to the information given by her in our interviews in the spring of 1885. "I want you to have all my statements correct in your book," said the noble lady, "and put my name to them; I want the truth, the full truth, to be known, and bear the responsibility of it...
"Joseph Smith, the son of the prophet, and president of the re-organized Mormon church, paid me a visit, and I had a long talk with him. I saw that he was not inclined to believe the truth about his father, so I said to him: 'You pretend to have revelations from the Lord. Why don't you ask the Lord to tell you what kind of a man your father really was?' He answered: 'If my father had so many connections with women, where is the progeny?' I said to him: 'Your father had mostly intercourse with married women, and as to single ones, Dr. Bennett was always on hand, when anything happened...'
Bennett wanted me to return to him a book I had borrowed from him. It was a so-called doctor-book. I had a rapidly growing little family and wanted to inform myself about certain matters in regard to babies, etc., -- this explains my borrowing that book. While giving Bennett his book, I observed that he held something in the left sleeve of his coat. Bennett smiled and said: 'Oh, a little job for Joseph; one of his women is in trouble.' Saying this. he took the thing out of his left sleeve. It was a pretty long instrument of a kind I had never seen before. It seemed to be of steel and was crooked at one end. I heard afterwards that the operation had been performed; that the woman was very sick, and that Joseph was very much afraid that she might die, but she recovered. (Mormon Portraits I, von Wymetal, Wilhelm, SLC: Tribune Printing & Pub., 1886, page 59-62).