title: Pregnancy length may vary by 5 weeks.
authors.forename: Bridget M
authors.initials: BM
authors.lastname: Kuehn
mesh_terms: D000367:Age Factors; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008598:Menstruation; D011247:Pregnancy / Q000502:physiology*; D011261:Pregnancy Trimester, First; D013997:Time Factors; D035501:Uncertainty