MacLennan v MacLennan 1958 S.C. 105; 1958 S.L.T. 12 (Outer House, Court of Session, Scotland) was a civil law case that required the court to determine if artificial insemination constituted adultery. Mr and Mrs MacLennan were married in August 1952 but their marriage was not a success. The couple separate shortly afterwards and Mrs MacLennan went to U.S.A. In July 1955 she had a baby girl. Mr MacLennan sued for divorce citing adultery. Mrs MacLennan defended this action and claim she had conceived the child through artificial insemination not through adultery. The Court of Session was faced with defining adultery and whether or not artificial insemination could be defined as under this heading.