title: Menstrual cycle phase at the time of rape does not affect recovery of semen or amplification of STR profiles of a suspect in vaginal swabs.
abstract: The effect of women menstrual cycle on the forensic analysis of rapes was studied in a random group of 170 victims aged among 10 and 51 years. Participants were grouped according to the day of the menstrual cycle in which they were at the moment of the assault. From each participant, samples of vaginal fluid were taken and analyzed for sperm cells, p30 protein, total human DNA and human male DNA. Moreover, amplification of suspect's autosomal STR and Y-STR was attempted. Suspects' autosomal STR profiles were obtained from 92 of the 101 samples in which spermatozoa were found; and Y-STR haplotype was obtained in 1 of the 9 samples where autosomal STR profiles of a male were not obtained. On the other hand, Y-STR haplotypes were obtained in 2 of the 21 samples negative for sperm cells but positive for p30 protein. Y-STR haplotypes were also obtained in 11 of the 48 samples negative for sperm cells and p30 protein. It was found that groups of participants did not differ on the recovery of sperm cells from the vaginal swabs, quantification of suspect's DNA or amplification of their STR profiles. It is concluded that the menstrual cycle phase at the moment of the sexual assault does not affect the main outcomes of the forensic investigation of rapes.
authors.affiliation: Departamento de Ciencias Forenses, Organismo de Investigación Judicial, San José, Costa Rica; Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica. Electronic address: LCerdasA@poder-judicial.go.cr.
authors.forename: Loreley
authors.initials: L
authors.lastname: Cerdas
authors.affiliation: Departamento de Ciencias Forenses, Organismo de Investigación Judicial, San José, Costa Rica.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Herrera
authors.affiliation: Departamento de Ciencias Forenses, Organismo de Investigación Judicial, San José, Costa Rica.
authors.forename: Glenn
authors.initials: G
authors.lastname: Arrieta
authors.affiliation: Departamento de Ciencias Forenses, Organismo de Investigación Judicial, San José, Costa Rica.
authors.forename: Concepción
authors.initials: C
authors.lastname: Morelli
authors.affiliation: Departamento de Ciencias Forenses, Organismo de Investigación Judicial, San José, Costa Rica.
authors.forename: Karla
authors.initials: K
authors.lastname: Álvarez
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Aarón
authors.initials: A
authors.lastname: Gómez
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D016172:DNA Fingerprinting / Q000379:methods*; D005260:Female; D005554:Forensic Medicine / Q000379:methods; D006801:Humans; D008297:Male; D008597:Menstrual Cycle; D018895:Microsatellite Repeats / Q000235:genetics*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011902:Rape; D012661:Semen; D014626:Vaginal Smears; D055815:Young Adult
keywords: Autosomal STR; Menstrual cycle; Rape; Sperm cells; Y-STR; p30 protein