Pregnancy nutrition for weeks 17–20
This period is often when movement becomes obvious, and the fetus keeps building capacity for life outside the womb.
What is developing
- Fingerprints and nails form; grip strengthens.
- Movement increases and responses to sound can begin.
- Weight gain starts to accelerate and the fetus begins to "fill out" over time.
Nutrient highlights
These highlights organize food comparisons. Daily nutrient needs continue throughout pregnancy; priority labels are not trimester-specific intake targets or medical advice.
Iron
High priorityIron supports red blood cell production and oxygen delivery for both you and the fetus.
Iron needs increase in pregnancy and iron deficiency is common; adequacy supports healthy red blood cells.
Protein
High priorityGrowth is the main job right now, and protein is the main building material.
Protein needs rise in pregnancy overall and support fetal growth.
DHA
Medium priorityBrain and nervous system development continues all pregnancy long.
Omega-3s (including DHA) contribute to brain and retina structure.
Vitamin C
Supporting priorityVitamin C supports collagen formation and helps improve iron absorption from plant foods.
Vitamin C is involved in collagen synthesis and can increase nonheme iron absorption.
Practical notes
- Second trimester often means about 340 extra calories/day, depending on your starting weight and situation.
Sources
- NHS 111 Wales: Pregnancy week by week (weeks 17-20)
- CDC: Weight gain during pregnancy (calorie needs by trimester)
- health.gov MyHealthfinder: Eat healthy during pregnancy (calorie needs by trimester)
- NIH Office of Dietary Supplements: Iron (Health Professional)
- NIH Office of Dietary Supplements: Dietary Supplements and Life Stages: Pregnancy (Health Professional)
- National Academies Press: Dietary Reference Intakes (Protein and Amino Acids; pregnancy RDA summary)
- NIH Office of Dietary Supplements: Omega-3 Fatty Acids (Health Professional)
- NIH Office of Dietary Supplements: Vitamin C (Health Professional)