Educational content, not medical advice. Clinical review of this page is in progress.
Pregnancy comes with a lot of unfamiliar vocabulary. Here’s a quick-reference glossary of common terms.
Common Terms
- Gestational age: Pregnancy duration counted from the last menstrual period.
- hCG: Human chorionic gonadotropin, the hormone detected by pregnancy tests.
- LMP: Last menstrual period.
- Trimester: One of three roughly 13-week phases of pregnancy.
- Quickening: The first felt fetal movements, usually 16–25 weeks.
- Braxton Hicks: Irregular practice contractions before true labor.
- Viability: The gestational age at which a fetus could potentially survive outside the womb with medical support (around 24 weeks).
- Zygote: A fertilized egg, before it begins dividing into an embryo.
Dating Terms
Gestational age: time since the first day of the last menstrual period. Fetal age: time since conception. EDD: estimated due date. See gestational age vs. fetal age.
Fertility Terms
Ovulation: release of an egg. Luteal phase: time between ovulation and the next period. Implantation: embryo attaching to the uterine lining. hCG: the hormone detected by pregnancy tests. See ovulation and implantation and hCG.
Pregnancy and Birth Terms
Trimester: one of three roughly 13-week stages. Braxton Hicks: irregular practice contractions. Effacement: thinning of the cervix before labor. See the labor guide.
Related Resources
Sources and Further Reading
This page is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your OB-GYN or midwife about your own pregnancy.