LMP

Medical abbreviation · Obstetrics & Gynecology

LMP
Stands forLast menstrual period
CategoriesMedical

LMP stands for Last menstrual period, an obstetrics & gynecology abbreviation.

First day of a woman's most recent menstrual period, used to date a pregnancy and to calculate the estimated due date. It is recorded at nearly every gynecologic and prenatal visit and before procedures or medications that could affect a pregnancy.

Example: LMP 3/14, regular 28-day cycles; EDD by LMP 12/19, consistent with 8-week ultrasound.

Usage notes

Because pregnancy is counted from the LMP, a woman is considered "two weeks pregnant" around the time of conception. Naegele's rule estimates the due date by adding seven days to the LMP, subtracting three months and adding a year. Irregular cycles or uncertain dates make early ultrasound dating more reliable.

More obstetrics & gynecology abbreviations

  • IUP – Intrauterine pregnancy
  • IUPC – Intrauterine pressure catheter
  • IVF – In vitro fertilization
  • LARC – Long-acting reversible contraception
  • LEEP – Loop electrosurgical excision procedure
  • LGA – Large for gestational age
  • LSIL – Low-grade squamous intraepithelial lesion
  • MHT – Menopausal hormone therapy
  • MSAFP – Maternal serum alpha-fetoprotein
  • MVA – Manual vacuum aspiration
  • NIPT – Noninvasive prenatal testing
  • NST – Nonstress test

See all 89 obstetrics & gynecology abbreviations →

This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.