A–Z Glossary

Fetus

A fetus is the developing baby after the embryonic period, generally beginning at about 10 weeks of pregnancy.

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Can bending harm the baby myth

Can bending harm the baby myth

Why the bending myth is so persistent Pregnancy often becomes a time of heightened vigilance. A movement that once felt automatic, like reaching into a low cupboard or picking something off the floor, can suddenly trigger fear. That reaction is common and deserves empathy, because many people receive mixed messages from family, social media, and […]

Key milestones during each month of pregnancy

Key milestones during each month of pregnancy

How pregnancy months relate to weeks and trimesters Pregnancy is commonly divided into three trimesters: weeks 1 to 12, weeks 13 to 27, and weeks 28 to birth. Month-by-month descriptions are approximate because calendar months do not align perfectly with gestational weeks. Clinically, your care team will usually communicate in weeks and days, such as […]

Month 3 of pregnancy: end of first trimester and key milestones

Month 3 of pregnancy: end of first trimester and key milestones

Where month 3 fits in pregnancy dating Pregnancy dating can be confusing because it is measured from the first day of the last menstrual period, not from the date of conception. This means that by the time a pregnancy test is positive, a person is often already considered about 4 weeks pregnant. According to standard […]

Pregnancy month-by-month overview

Pregnancy month-by-month overview

How pregnancy months are counted Pregnancy is medically dated in weeks, not calendar months, because fetal development changes quickly and because months vary in length. A 40-week pregnancy is divided into the first trimester through week 12, the second trimester from weeks 13 to 27, and the third trimester from week 28 until birth. Month-by-month […]

Baby size and fetal development milestones by trimester

Baby size and fetal development milestones by trimester

Understanding pregnancy dating and fetal size measurements Pregnancy is usually dated from the first day of the last menstrual period, even though conception typically occurs about two weeks later. This is why a person who is described as 8 weeks pregnant has usually had about 6 weeks of embryonic or fetal growth. Early ultrasound can […]