Fetal development week 5

This is an automatically translated article.

The article was professionally consulted by Specialist Doctor II Tran Thi Mai Huong - Department of Obstetrics and Gynecology - Vinmec Hai Phong International General Hospital.
Entering the fifth week of pregnancy, the parts and organs in the baby's body gradually form and develop. At this stage, the baby needs to be provided with all the necessary nutrients for healthy development, so pregnant mothers need to pay close attention to the necessary nutrients and rest.

1. How does the 5th week fetus develop?

In the 5th week of pregnancy, the fetus will grow strongly, the size has grown significantly, about 6mm long, and looks like the shape of a small tadpole.
During this week, the nervous system and circulatory system begin to differentiate, other organs also thrive. The blastocyst forms the tricuspid embryo, including the outer, inner, and middle:
Outer embryo: Forms the nervous system, inner ear membrane, vitreous, epidermis, hairs, hair, and nails. Mesoblast: Forms muscle, bone, excretory system, and circulatory system. Inner embryonic leaf: Differentiated into digestive system, body gland, epidermal organization of respiratory system, bladder, vestibule and urethra. The highlight in the development of the 5-week-old fetus is the formation of a circulatory system from the mesoderm, so the baby's heartbeat has appeared and has a frequency of 100-160 beats/minute, twice the human heart rate. big. In addition, the contours of the baby's face begin to become clearer, the back of the head will develop faster than the front. Most of the development of the fetus during the fifth week is concentrated in the brain with about 100 brain cells being formed every minute. Therefore, mothers will often feel hungry, or nauseous because your body needs more energy sources to provide and support the development of your baby. In addition, the baby's gonads are also starting to form, but we still can't determine the baby's sex but have to wait a bit longer.
When the pregnant mother enters the 5th week, the organs such as the heart, nervous system and blood vessels of the fetus are very sensitive and easily damaged if subjected to strong impacts, so it is easy to lead to allergies. congenital. You should be really cautious during this sensitive period, especially not to be exposed to radiation or X-rays, not to exercise too hard, to avoid catching colds and flu, and not to use medicine without a prescription. doctor's prescription.
Details of fetal development week by week, every parent should learn:

2. 5 weeks pregnant has a fetal heart yet?

As mentioned above, the fetal heart at 5 weeks has appeared because the circulatory system is formed from the mesoderm. Through the activity of the fetal heart, the doctor will base it on it to monitor the baby's health status.

Some people who go to the antenatal clinic this week but have not detected the baby's heartbeat should be calm. You can wait another week or two as each baby develops differently. Considering each child's case, the doctor will give an appropriate treatment plan.

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

To be able to draw an accurate conclusion that the 5-week-old fetus has entered the uterus or not is really difficult to say. Because the time when the fetus "implants" in the uterus of each woman is different, and there is no specific time.
According to studies, during fertilization, up to 250 million sperm are released in each ejaculation to find an egg. Only the strongest and fastest sperm can meet the egg to fertilize and form a zygote. At that time, the process of conception officially begins.
Normally, the process of stable implantation in a woman's uterus will take about 7-10 days, however, some people can take up to 13-15 days. Therefore, it is very difficult to determine the time of ovulation. Obstetricians and gynecologists usually calculate gestational age based on the first day of the last menstrual period. This calculation can move about 1-2 weeks, so many pregnant women are counted as 5 weeks pregnant but have not yet entered the uterus.
In general, there is no specific number to determine whether a 5-week fetus has entered the uterus or not.

4. Causes of late pregnancy into the uterus

Here are some of the main causes of a later-than-normal pregnancy, including:
Fallopian tube and fallopian tube abnormalities: Women with narrow and small fallopian tubes, with a history of Fallopian tube surgery, the fallopian tube is scarred or infected, making the time for the pregnancy to enter the uterus slower than usual. The mother's body: Depending on the location, body characteristics, menstrual cycle of each person, the time when the zygote enters the uterus is different. Ectopic pregnancy: In case you have missed your period for 14 days, the pregnancy test shows 2 lines but when the ultrasound still does not see the pregnancy into the uterus, there is a high chance that you have an ectopic pregnancy - zygote in and grow in the fallopian tubes and fallopian tubes instead of in the mother's uterus. This is a very dangerous case, if not handled promptly, it can cause abdominal bleeding, seriously affect the mother's life or lose her ability to reproduce later.

5. Some signs that the fetus has entered the uterus

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

Increases body temperature: Because the mother's body has to make more blood during this time, blood flow also increases rapidly, in addition, metabolism also takes place more to provide nutrients. and oxygen for the baby.
Bleeding warning of pregnancy: when the zygote has successfully moved into the uterus and implanted there, you may see some light pink or dark brown blood in the vagina, accompanied by pain in the lower abdomen. This phenomenon makes many people mistakenly think that their period is about to happen.
Body fatigue: is caused by high levels of hCG, progesterone and estrogen hormones after successful fertilization of the egg. This sudden change leaves you feeling tired and irritable.
There are also some other signs such as nausea, vomiting, loss of appetite, sensitivity to smell, missed period.

6. Advice for pregnant women in the 5th week of pregnancy

The first months of pregnancy are a very important time for the development of the fetus. To have a healthy pregnancy and ensure the best development of your baby, you should refer to the following tips:
Should have early and scheduled antenatal care. Good prenatal care is an essential step in ensuring the health of both mother and baby. You should see your doctor for a physical exam, including your height, weight, blood pressure, and general health. Avoid eating harmful foods. Foods such as unpasteurized cheese, unpasteurized milk or juices, raw eggs, meat, fish, unprocessed seafood, hot dogs, cold cuts, and fish with high levels of mercury , ... can cause food poisoning due to bacterial or parasitic infection, leading to a high risk of birth defects in the fetus, or even miscarriage. Actively supplement with folic acid in the first trimester to minimize the possibility of birth defects, neural tube defects or congenital heart disease for the fetus. Supplement enough vitamins, iron and calcium for the body through eating enough nutrients and taking multivitamins. Do not arbitrarily use any medicine, including functional food products without the permission of the 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 birth weight, miscarriage, language skills and slower actions than usual. Relax your body with gentle activities.

The first trimester is the most sensitive time during pregnancy. To help the 5th week fetus develop well, mother and baby are healthy, parents need to note:
Understand early signs of pregnancy, pregnancy poisoning, bleeding in pregnancy. Timely, correct and sufficient first prenatal check-up, avoiding too early/too late. Fetal malformation screening at 12 weeks detects dangerous fetal malformations that can be intervened early. Distinguish between normal vaginal bleeding and pathological vaginal bleeding for timely intervention to maintain pregnancy. Screening for thyroid disease in the first 3 months of pregnancy avoids dangerous risks before and during delivery. Vinmec currently has many maternity packages (12-27-36 weeks), in which the 12-week maternity package helps monitor the health of mother and baby right from the beginning of pregnancy, early detection and timely intervention of health issues. In addition to the usual services, the maternity monitoring program from 12 weeks has special services that other maternity packages do not have such as: Double Test or Triple Test to screen for fetal malformations; Quantitative angiogenesis factor test to diagnose preeclampsia; thyroid screening test; Rubella test; Testing for parasites transmitted from mother to child seriously affects the baby's brain and physical development after birth.
Doctor Tran Thi Mai Huong has 25 years of experience in examination and treatment in the field of Obstetrics and Gynecology, lower tract surgery, laparoscopic surgery. Has held the position of deputy head of the School of Obstetrics and Gynecology, deputy head of the delivery department - Hai Phong Obstetrics and Gynecology Hospital. Having high expertise and strengths in the following areas:
Lower tract surgery Laparoscopic surgery Difficult obstetric surgery For more information about the 12-week maternity package and registration, you can contact us. Contact the clinics and hospitals of Vinmec health system nationwide.

Please dial HOTLINE for more information or register for an appointment HERE. Download MyVinmec app to make appointments faster and to manage your bookings easily.

Articles refer to sources: Mayoclinic.org, Webmd.com, Babycenter.com, Whattoexpect.com