Fetal development week 5

The article was consulted professionally by Specialist Ii Tran Thi Mai Huong – Obstetrics and Gynecology Department – Share99 Hai Phong International Health Hub.

Entering the fifth week of pregnancy, parts and bodies in the baby's body gradually form and develop. At this stage, babies need to be provided with the necessary nutrients to develop healthy, so pregnant mothers need to pay close attention to the necessary nutrient supplements and rest.

1. How does the 5th week fetus develop?

By the 5th week of pregnancy, the fetus will grow strongly, the size of which has now had significant growth, is about 6mm long, and looks like the shape of a small tadpole.

This week, the nervous system and the 3l system begin to differentiate, other muscles also thrive. The embryonic vesicple forms three-leaf embryo sprouts, including outer, in and between:

  • Outer embryo leaves: Formation of the nervous system, the membrane of the ear, the glass, the epidermis, hair, hair, and nails.
  • Middle embryo leaves: Formation of fleshy muscles, bones, excretory system and tissue that connect the re 3dular system.
  • Leaves of the embryo in: Differentiate into the digestive system, glands, epidermal organization of the respiratory system, bladder, fore bedes and urethra.

The highlight of the development of a 5-week-old fetus is the formation of a 3dular system from mesoderm, so the baby's heart rate has appeared and has a frequency of 100-160 beats per minute, twice the heart rate of adults. In addition, the lines on the baby's face begin to clear, the back end will grow faster than the front. Almost all fetal development in the fifth week is focused on the brain with about 100 brain cells formed every minute. Therefore, mothers will often feel hungry, or tincture because your body needs more energy to provide and support the development of your baby. In addition, the fetal sex glands also begin to form, but we have not yet been able to determine the sex of the baby but have to wait a little longer.

When the pregnant mother enters the 5th week,the muscles such as the cardiovascular, nervous system and veins of the fetus are extremely sensitive and vulnerable if subjected to strong effects, so it is easy to lead to birth defects. You should be really cautious during this sensitive period, especially not to be exposed to radioactive rays or X-rays, not to exercise too strongly, avoid getting the flu and not use the drug without a doctor's prescription.

In detail about the development of the fetus week by week, every parent should find out:

2. Is a 5-week-old pregnant with a pregnant heart?

As said above, the gestational heart at the 5th week has appeared due to the existing system formed from mesoderm. Through the operation of the gestational heart, the doctor will base it on it to monitor the state of health of the baby.

Fetal development week 5

Pregnant heart at 5 weeks

Some people who go to a pregnancy check-up this week but have not yet detected their baby's pregnancy heart should also be calm. You can wait about another 1 or 2 weeks because each baby will develop differently. In the case of each child, the doctor will give the appropriate treatment direction.

3. Has a 5-week-old fetus entered the uterus?

To be able to come to an accurate conclusion that a 5-week-old fetus has entered the uterus or not is really difficult to say. Because the moment of pregnancy "nesting" in the uterus of each female is different, and no time is specific.

According to studies, during fertilization, up to 250 million sperm are released during each ionization in search of eggs. Only the healthiest and fastest sperm can meet eggs for fertilization and ment mentva formation. At that time, the process of conception was officially started.

Usually, the process of stable nesting in the uterus of the woman will take about 7-10 days, however, there are some people who again up to 13-15 days. Therefore, it is difficult to determine the time of ovulation. Obstetrician and gynecologist usually calculates gestational age based on the first day of the last period. This calculation can displace about 1-2 weeks, so many pregnant mothers are counted as 5 weeks pregnant but have not yet entered the uterus.

In general, there are no specific figures to determine whether the 5-week fetus has entered the uterus.

4. Causes of late pregnancy in the uterus

Here are a few main causes of pregnancy entering the uterus later than usual, including:

  • Abnormalities of the ovopian tubes and proboscis: Women with narrow and small ovoply ducts, with a history of ovarian surgery, a scarred or inflamed proboscis, make the gestational period entering the uterus slower than usual.
  • Mother's location: Depending on the body, body characteristics, menstrual cycle of each person, the time when the prince enters the uterus is different.
  • Extrasterical pregnancy: In case you have been delayed by 14 days, the pregnancy test stick shows 2 lines but when the ultrasound has not yet seen the pregnancy into the uterus, there is a high likelihood that you have had an extrasolal pregnancy – the este stays and develops in the ovulation and proboscis instead of in the mother's uterus. This is a very dangerous case, if not handled in time can cause abdominal bleeding, seriously affect the life of the mother or loss of fertility later.

5. Some signs that the fetus has entered the uterus

Once the pregnancy has entered the uterus, you may see the following signs:

Fetal development week 5

Some signs that the fetus has entered the uterus

Increase the temperature of the body: Since the mother's body has to produce more blood during this time, the flow of blood also increases rapidly, in addition to more metabolism to provide nutrients and oxygen to the baby.

Gestational bleeding: when the pod successfully moves into the uterus and nests there, you will likely see a slight pink or dark brown blood area, accompanied by lower abdominal pain. This phenomenon causes many people to mistakenly think that menstruation is imminent.

Body fatigue: is caused by the hormones hCG, progesterone and estrogen elevated after successful fertilization of eggs. This sudden change makes you feel tired and uncomfortable.

There are also some other signs such as nausea, vomiting, loss of appetite, sensitivity to smell, slow menstruation.

6. Tips for pregnant mothers in the 5th week of pregnancy

The first months of pregnancy are extremely important periods for fetal development. To have a healthy pregnancy and ensure the best development of the baby, you should refer to the following tips:

  • Early and scheduled pregnancy check-up is recommended. Good pre-birth care is an essential step to ensure the health of both mother and baby. You should see your doctor for physical examination, including height, weight, blood pressure, and general health in general.
  • Avoid eating harmful foods. Foods such as unclaved cheese, milk or uns sterilized juices, raw eggs, meat, fish, un processed seafood, sausages, cold cuts, fish with high mercury content,… can cause food poisonings caused by bacterial or parasite infections, leading to a high risk of birth defects in the fetus, or even miscarriages.
  • Actively supplement folic acid during the first trimepcle to minimize the likelihood of birth defects, neurological tube defects or congenital heart disease for the fetus.
  • Replenish your body with vitamins, iron and calcium through adequate eating and multivitamins.
  • Do not arbitrarily use any drugs, including functional food products without the permission of a doctor.
  • Avoid smoking, drinking alcohol and stimulants. These substances adversely affect the development of the fetus, causing serious health problems such as premature birth, low weight, miscarriage, language ability and slower action than usual.
  • Relax your body with gentle activities.

Fetal development week 5

Relax your body with gentle activities

The first 3 months are the most sensitive time during pregnancy. To help the 5th week fetus develop well, mothers and babies are healthy, parents should note:

  • Understand early signs of pregnancy, pregnancy poisoning, bleeding during pregnancy.
  • The first pregnancy examination is timely, correct and sufficient, avoiding the examination too early / too late.
  • Screening for fetal malformations at the 12th week detects dangerous fetal malformations that can intervene early.
  • Distinguishes the usual vaginal bleeding and pathology vaginal bleeding for timely pregnancy retention intervention.
  • Screening for thyroid disease in the first 3 months of pregnancy avoids dangerous risks before and during childbirth.

Share99 currently has many maternity packages (12-27-36 weeks), of which the 12-week package maternity program helps monitor the health of mothers and babies at the beginning of pregnancy, early detection and timely intervention of health problems. In addition to the usual services, the 12-week maternity monitoring program has special services that other maternity packages do not have such as: Double Test or Triple Test for Fetal Malformations; dosing tests of neovascular factors for pre-seizure diagnosis; thyroid screening tests; Rubella test; testing for parasites transmitted from mother to child seriously affects the brain and physical development of the baby after birth.

Dr. Tran Thi Mai Huong has 25 years of experience in examination and treatment in the field of Obstetrics and Gynecology, Lower Road Surgery, Laparoscopic Surgery. Held the position of deputy head of obstetrics and gynecology department, deputy head of delivery department – Hai Phong Obstetrics and Gynecology Health Hub. Have high expertise and strengths in the field of:

  • Lower line surgery
  • Laparoscopic surgery
  • Difficult obstetric surgeries

For more information about the 12-week package maternity program and registration, you can contact Share99 clinics and hospitals nationwide.

For direct advice, please click hotline number or register online HERE. In addition, you can register for remote consultation HERE

Article reference source: Mayoclinic.org, Webmd.com, Babycenter.com, Whattoexpect.com


  • Benefits of pregnancy in the 3 months between pregnancy
  • Benefits of pregnancy in the last 3 months of pregnancy
  • Instructions for supplementing multivitamins and Folic Acid for people preparing for pregnancy

About: Minh Quynh

b1ffdb54307529964874ff53a5c5de33?s=90&d=identicon&r=gI am the author of Share99.net. I had been working in Vinmec International General Hospital for over 10 years. I dedicate my passion on every post in this site.


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