Second Trimester: What to Expect

What Is the Second Trimester?

The second trimester is the middle of pregnancy's three stages, running from week 14 to the end of week 27. It is the central stage of the pregnancy trimesters, the framework that divides pregnancy into three ordered stretches. The second trimester follows the first and leads into the third. This page explains when the second trimester starts, how many weeks it lasts, what happens during it, and which nutrients matter most at this stage.

When Does the Second Trimester Start?

The second trimester starts at week 14 of pregnancy, following the end of the first trimester. This start point uses the dating convention in the Australian Government Department of Health's Clinical Practice Guidelines: Pregnancy Care. Week 14 marks the boundary where the first trimester ends and the middle stage begins.

How Many Weeks Is the Second Trimester?

The second trimester lasts about 14 weeks, covering weeks 14 to 27 of pregnancy. It is the middle stretch of the roughly 40-week pregnancy under the same clinical dating convention. The stage ends at the close of week 27, when the third trimester begins.

What Happens in the Second Trimester?

The second trimester often brings easing symptoms and several key mid-pregnancy milestones. It is often called the golden period, because the early-pregnancy symptoms of the first trimester tend to settle. The typical milestones of the second trimester, recognised in Australian pregnancy care guidance, are listed below:

• Easing symptoms: nausea and tiredness often settle from around week 14.
• Anatomy scan: the mid-pregnancy ultrasound, usually offered around weeks 18 to 20.
• First movements: many women feel the first fetal movements, known as quickening, during this stage.

These milestones fall within the second trimester and mark the middle stage of pregnancy.

Which Nutrients Matter Most in the Second Trimester?

Iron and calcium are nutrients that are important in the second trimester of pregnancy. Under the NHMRC Nutrient Reference Values for Australia and New Zealand, iron and calcium needs rise during pregnancy. For detail on iron during pregnancy, see the guide to iron in pregnancy.

How Does Second-Trimester Nutrition Fit Your Whole Pregnancy?

Second-trimester nutrition is one stage of a whole-pregnancy nutrition picture that shifts as pregnancy progresses. The iron and calcium emphasis of the middle stage follows the folate focus of early pregnancy and precedes the later needs of the third trimester. For the complete view of women's nutrition across every stage, including how these nutritional needs fit together, see the guide to eating well in pregnancy.