Plain-English glossary

The fertility and pregnancy terms you'll come across, without the jargon.

LMP, Last Menstrual Period

The first day of your most recent period. Pregnancy dating traditionally counts from here, even though conception happens about two weeks later.

EDD, Estimated Due Date

Your "due date", about 40 weeks from your LMP. It's an estimate; most babies arrive within a week or two either side.

Gestational age

How far along your pregnancy is, measured in weeks and days from your LMP. "14 weeks pregnant" is a gestational age.

Ovulation

When an ovary releases an egg, usually around 14 days before your next period. It's the most fertile point of your cycle.

Fertile window

The roughly six days when conception is possible, the five days before ovulation plus ovulation day, based on how long sperm and egg survive.

Luteal phase

The part of your cycle from ovulation to your next period. It's usually fairly steady at around 14 days, which is why it helps predict ovulation.

Follicular phase

The first half of your cycle, from the start of your period up to ovulation. Its length varies most between people.

Implantation

When a fertilised egg attaches to the lining of the womb, usually 6-12 days after ovulation. Some people notice light "implantation" spotting.

Trimester

Pregnancy is split into three roughly equal stages: first (weeks 1-12), second (13-26) and third (27-birth), each with its own changes.

Dating scan

An ultrasound around 12 weeks that confirms how far along you are and refines your due date.

Anomaly scan

A detailed ultrasound around 20 weeks that checks baby's development. You may be able to find out the sex.

Full term

From 37 weeks, baby is considered ready to be born. "Early term" is 37-38 weeks and "full term" is 39-40 weeks.

Corrected age

For babies born early, their age adjusted to their original due date, often used to track development in the first couple of years.