My baby at 4 weeks of pregnancy

Pregnancy

Pregnancy week by week

Your Baby at 4 Weeks

As big as a sesame seed

Length

.05

Weight

<.04

At this stage of your pregnancy, your baby, now an embryo, is the size of a sesame or orange seed.

It's a small but significant marker of the life developing within you.

Reflect on this incredible fact the next time you peel an orange, and by next week, expect the embryo to have doubled in size.

What's new this week?

Baby’s Changes Overview

The embryo is now attached to the lining of your uterus

The embryo receives nourishment from your bloodstream

Open 3D Baby to see all changes

The embryo has successfully attached to the uterine lining and begins to derive nourishment directly from your bloodstream.
Composed of three distinct layers—ectoderm, mesoderm, and endoderm—your embryo is undergoing rapid development, laying the groundwork for all bodily systems.
Ectoderm: This outer layer is busy forming the neural tube, which will develop into your baby's brain, spinal cord, and nervous system, as well as the skin, hair, nails, and glands.
Mesoderm: The middle layer starts to shape the heart, circulatory system, muscles, bones, and subcutaneous tissue.
Endoderm: The innermost layer will differentiate into the lungs, intestines, early urinary system, thyroid, liver, and pancreas.
The formation of the primitive placenta and umbilical cord is already underway, ensuring your baby receives essential nutrients and oxygen.

As you marvel at the thought of your baby, now the size of a poppy seed, it's also the right time for the first exciting confirmation with a home pregnancy test.

Juliette, Midwife for 8+ years

Helping baby's development

Nutritious Diet: Embrace a diet rich in leafy greens, lean proteins, whole grains, and a variety of fruits and vegetables to nourish your growing baby.
Folate Intake: Don't overlook the importance of folate, a vital nutrient that plays a crucial role in preventing birth defects.
Stay Hydrated: Aim for at least 80 ounces of water and other hydrating fluids daily to support your body's increased needs during pregnancy.
Regular Exercise: Incorporating physical activity into your daily routine can enhance your and your baby's health, reduce stress, and improve overall well-being. Choose activities you enjoy, from walking and yoga to swimming.
Avoid Harmful Substances: It's essential to steer clear of tobacco, alcohol, and certain medications that could impact your baby's development. Seek your doctor's advice to explore safe alternatives, such as nicotine patches or gum, if needed.
Adequate Rest: Prioritizing sleep is key to your physical and emotional health during pregnancy. Strive for 7-9 hours of sleep each night and take naps to replenish your energy. Your body and your baby will benefit greatly from the rest.

Top Asked Questions

How accurate are home pregnancy tests?

Home pregnancy tests are quite accurate when used correctly after a missed period. They detect the hormone hCG, which is produced during pregnancy. Follow the instructions carefully for the most reliable results.

What is a missed period a sign of pregnancy?

A missed period can be one of the earliest signs of pregnancy. It occurs because the fertilized egg has implanted in the uterus, preventing the usual shedding of the uterine lining.

Should I be concerned about morning sickness?

Morning sickness is a common pregnancy symptom. While it can be uncomfortable, it's usually not a cause for concern. If it becomes severe and leads to dehydration, consult your healthcare provider.

What prenatal care do I need at this stage?

At this stage, it's essential to schedule your first prenatal appointment with a healthcare provider. They will conduct initial tests, discuss your medical history, and provide guidance on prenatal care and nutrition.