5th Week Pregnancy: Symptoms, Baby Development And Tips

Written by Shreeja pillai • 

You are now five weeks pregnant and at the beginning of the second month of your pregnancy. Did you know that your baby’s tiny heart begins to form in the 5th week of pregnancy? The second month is also when most women get to know they are pregnant. It is the time you may have your first prenatal check up.

Curious to know what else happens in this week of pregnancy? Read this MomJunction post to know more about the development of your baby at five weeks, the symptoms you may experience, and tips that you need to remember at this stage.

Baby Development

At five weeks gestation, the little one starts to develop quite rapidly. This also marks the embryonic period as the major structures begin to form.

  1. Size: Your baby is just the size of a grain that is less than 1/4th of an inch, at five weeks of pregnancy. It is tiny but visible and looks like a tadpole (1).
  1. Heart: The heart  is the first functional fetal organ to develop and starts to beat and pump blood at around day 21 or 22 after fertilization. It doesn’t mean that your doctor should detect the heart beat at this time. For detection of heart beat by normal obstetric sonography, you have to wait for a few more weeks.
  1. Brain: The neural tube starts to form. Later, it forms the spinal cord, brain, and other major nerves.
  1. Others: Some features that your baby develops or is developing at five weeks are (2) (3).
    • The liver produces blood cells; blood cell formation takes place for the first time
    • Even the kidneys are formed by the fifth week of pregnancy
    • Tiny and webbed fingers are formed
    • The face has a reptilian appearance
    • Eyes and limbs also start forming by this stage
    • The placenta is formed to provide nourishment to the baby
    • Gastrointestinal tract and the blood vessels develop

In the next section, we list the signs and symptoms you may experience during the fifth week of pregnancy.

Symptoms At Five Weeks Pregnancy

This is the week when the pregnancy hormones are at peak, and your pregnancy can be confirmed. At five weeks pregnant, your body starts to show the early pregnancy symptoms (4) (5).

  1. Fatigue: During the fifth week of pregnancy, you may feel exhausted because your body produces high levels of progesterone that is necessary to maintain the pregnancy. Also, your body works extra to produce more blood for the baby and hence becomes tired easily.
  1. Nausea and vomiting: Also known as morning sickness, this symptom shows soon after conception. It may last until the end of the first or second stage of pregnancy for some women, while a few may experience it throughout the nine months.
  1. Headache and mood swings: Hormonal fluctuations in the body could be responsible for headaches during the early weeks after conception. Some women may also experience mood swings during the fifth week of pregnancy and later.
  1. Light bleeding or spotting: This is implantation bleeding, which occurs after the embryo attaches to the uterus. Some women experience this, while some do not. You need not worry as it doesn’t last long. But always check with your doctor.
  1. Tender breasts: Some women might experience tender and swollen breasts with a tingling sensation.
  1. Others: Frequent urination, food cravings, food aversions, heartburn, and indigestion could be other symptoms that some women might experience as they reach the fifth week of their pregnancy.

Whether you’re a first-time mom or have had children before, some of these physical changes can be overwhelming. If these changes are bothering you, read on for tips on how to manage the changes that occur at this time.

Your Checklist At Five Weeks Pregnancy

The initial phase of pregnancy can be a vulnerable one and would require you to take care of yourself and the little one in your belly. Here are a few tips you can follow to stay healthy.

  1. Visit the doctor: This might be your first appointment with the doctor after the pregnancy is confirmed. Your blood pressure and weight will be checked. The doctor might ask you several questions such as the date of your last menstrual period, previous pregnancies, and allergies to medicines or anything else.

They may suggest a specific diet and supplements, plus any medications if necessary, based on the information you share. So be open with your doctor during the initial check-up.

  1. Eat healthy foods and stay hydrated: It is essential to follow a well-balanced diet that includes vegetables, fruits, nuts, dairy products, and grains. Also, make sure that you are drinking enough water.
  1. Limit caffeine and avoid junk food: Limit intake of coffee, fried and sugary food and stop consumption of alcohol and smoking altogether as that can adversely impact the pregnancy.
  1. Take prenatal vitamins: If you have been taking prenatal vitamins before pregnancy, you may continue them. However, consult the doctor as they may change the medications or the dosage if necessary.
  1. Take rest: As you tend to get tired quite easily now, take rest whenever possible. Also, don’t exhaust yourself by doing strenuous activities during this time of your pregnancy.

The 5th week of pregnancy begins the embryonic period when the organs and structures develop. Although it is not possible to detect a heartbeat on the 5th-week ultrasound, all healthy babies will have a heart rate from this time. Early pregnancy symptoms such as mood swings, headaches, and nausea are observed too. It will help if you start living a healthy lifestyle, eat nutritious meals, and take prenatal vitamins. Anything that could harm the developing fetus should be avoided.


1. What happens in the second month of pregnancy; Plannedparenthood.org
2. Prenatal Form and Function – The Making of an Earth Suit; The Endowment For Human Development
3. Pregnancy Week By Week; Due Date Calculator
4. Pregnancy: Signs, Symptoms and Health; Online Nursing Regis College
5. Week 5 – Your 1st Trimester; NHS
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