No, there wont be any harm to the implanted embryo due to the contractions of the uterus occurring during orgasm (whether through masturbation or intercourse). Yes, you heard me right! One can even have sexual intercourse around the time of IVF. In fact a large research study published in the 'Human Reproduction' journal last year says that exposure to semen around the time of embryo implantation in IVF cycles can promote embryo development. So, no worries about masturbatory or intercourse orgasms.