Our Menstruation Main Article provides a comprehensive look at the who, what, when and how of Menstruation
Definition of LMP
LMP: Abbreviation for "last menstrual period."
By convention, pregnancies are dated in weeks starting from the first day of a woman's last menstrual period (LMP). If her menstrual periods are regular and ovulation occurs on day 14 of her cycle, conception takes place about 2 weeks after her LMP. A woman is therefore considered to be 6 weeks pregnant 2 weeks after her first missed period.
A woman's obstetric date is different from the embryologic date (the age of the embryo). The obstetric date is about 2 weeks longer than the embryologic date.
Last Editorial Review: 10/9/2012
Back to MedTerms online medical dictionary A-Z List
Need help identifying pills and medications?
- Allergic Skin Disorders
- Bacterial Skin Diseases
- Bites and Infestations
- Diseases of Pigment
- Fungal Skin Diseases
- Medical Anatomy and Illustrations
- Noncancerous, Precancerous & Cancerous Tumors
- Oral Health Conditions
- Papules, Scales, Plaques and Eruptions
- Scalp, Hair and Nails
- Sexually Transmitted Diseases (STDs)
- Vascular, Lymphatic and Systemic Conditions
- Viral Skin Diseases
- Additional Skin Conditions