4 Weeks Pregnant - What Happens To The Fetus? Sensations, Abdominal Pain

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Video: 4 Weeks Pregnant - What Happens To The Fetus? Sensations, Abdominal Pain

Video: 4 Weeks Pregnant - What Happens To The Fetus? Sensations, Abdominal Pain
Video: 4 Weeks Pregnant - Your Fourth Week Of Pregnancy 2023, December
4 Weeks Pregnant - What Happens To The Fetus? Sensations, Abdominal Pain
4 Weeks Pregnant - What Happens To The Fetus? Sensations, Abdominal Pain

4 weeks pregnant

A gestation period of 4 weeks is an important stage in its course, one of the crisis periods in the development of the embryo. At this time, the most important organs and systems of the child are laid and begin to develop. The course of pregnancy and the health of her unborn child depend on how the woman will live this period, how she will relate to her health.


  • Pregnancy calculation methods
  • What happens to the fetus at this time?
  • What does a woman feel at 4 weeks pregnant?
  • Condition of the uterus and endometrium
  • Pregnancy confirmation methods
  • Hormones at 4 weeks
  • When to see a doctor?
  • Pain in the abdomen and lower back at 4 weeks
  • Vaginal discharge at 4 weeks
  • Fever and colds at 4 weeks
  • Nutrition at 4 weeks of gestation
  • Sex at week 4

Pregnancy calculation methods

Pregnancy calculation methods
Pregnancy calculation methods

The main method for determining the duration of pregnancy is the method used by the gynecologist at the antenatal clinic, or the obstetric method. He calculates the gestational age from the first day of the last menstruation and prescribes planned instrumental and laboratory tests based on this date.

The embryonic counting method takes the ovulation date as a starting point and lags behind obstetric time by about 2 weeks. Women may believe that their pregnancy began on the day when the expected period did not come. In order not to cause confusion when communicating with a doctor, it is recommended to adhere to the obstetric method.

What happens to the fetus at this time?

According to the obstetric method, at 4 weeks, the zygote, or fertilized egg, begins to rapidly divide. It produces many cells with different structures and functions. Actually, it is not yet a fruit. An accumulation of cells is called a morula, or blastocyst. In shape, it resembles a multi-chambered berry, not yet attached to the endometrium of the uterus. It is difficult to name the exact parameters of the blastocyst, since it is constantly growing.

Approximate parameters of the future embryo:

  • Weight - 0.5 mg;
  • Growth - 0.36-1 g.

Figuratively speaking, it is comparable in size to a poppy seed.

If we count the gestational age according to the embryonic method, at 4 weeks the embryo has already taken root in the uterine cavity and continues to develop intensively.

At this stage, it is a seed disk and consists of 3 layers:

  • Primary ectoderm is the basis of skin, hair, tooth enamel, eye lenses, cells of the nervous system;
  • The mesoderm is the basis for the formation of future organs, skeleton, muscle tissue, circulatory, excretory and reproductive systems;
  • Endoderm is the basis of the respiratory and digestive systems, liver, thyroid and pancreas.

The future head of the fetus at the moment looks like a small droplet. The placenta has already begun to form. While it is still very primitive, it consists of 2 layers. The tissues of the future placenta are already connected to the tissues of the uterus, which allows the embryo to be supplied with food and oxygen.

The following extraembryonic organs are responsible for nutrition:

  • Chorion is a prerequisite for a real placenta, which will form up to 12 weeks, from 4 weeks at the place of contact of the embryo with the endometrium of the uterus, a vascular network begins to form;
  • Amnion is a kind of "packing" of the embryo, a prerequisite for the fetal bladder, which protects the fetus from physical impact and drying;
  • The yolk sac is a supply of nutrients for the embryo, the basis of hematopoiesis up to 7-8 weeks of pregnancy.

Without a yolk sac, the existence of an embryo is impossible, if its functions are impaired or a congenital pathology occurs, a miscarriage occurs. When conducting an ultrasound scan based on the state of the yolk sac, the doctor determines the quality of pregnancy and the viability of the embryo.

Studies have shown that male genes are responsible for the formation of extraembryonic organs. We can say that the function of protection and provision is inherent in a person even before birth.

By the end of 4 weeks, blastogenesis ends - the initial stage of embryonic development.

What does a woman feel at 4 weeks pregnant?

What a woman feels at 4 weeks pregnant
What a woman feels at 4 weeks pregnant

If the pregnancy was unplanned and the woman does not assume that she is pregnant, it is possible that she is not experiencing any change in well-being. But this does not happen often, in most cases a woman's mental state changes, she becomes extremely emotional, touchy and tearful, irritable.

Additional sensations:

  • The perception of smells and tastes of familiar food has changed;
  • The figure has become somewhat heavier due to hormonal changes;
  • There was swelling of the limbs;
  • There was nausea, in some cases vomiting (early toxicosis);
  • There were pulling pains in the lower back and lower abdomen;
  • Increased urination;
  • Vaginal discharge takes on the character of thick mucus;
  • There was an increased sensitivity of the mammary glands.

It is quite possible that, due to early toxicosis, a woman will not recover, but, on the contrary, will lose weight. Do not worry about this if there are no other symptoms besides loss of appetite.

Condition of the uterus and endometrium

The size of the uterus at 4 weeks of gestation practically does not increase; it is still within the boundaries of the small pelvis. Its structure changes - the uterus becomes swollen, the tissues in the isthmus area soften, which gives it little mobility. Both the uterus and its cervix become bluish in color due to blood flow. A mucous plug begins to form in the cervical canal, protecting the fetus from bacterial infection from the outside.

The endometrium thickens, its structure changes - new blood vessels grow, the number of glandular cells increases, which are subsequently transformed into the placenta. At this stage, such changes ensure the viability of the embryo, its respiration and nutrition. Due to the large number of blood vessels, the endometrium becomes bluish in color. Its thickness at 4 weeks, measured by the embryonic method, is about 2 cm.

Pregnancy confirmation methods

Pregnancy confirmation methods
Pregnancy confirmation methods

By the end of obstetric week 4, there is already an opportunity to confirm or deny pregnancy.

Applied methods:

  • Test strips for determining pregnancy - may not show a positive result, although there is already a pregnancy due to the low concentration of hCG in the woman's urine, it is possible that the result will change after 2-4 days;
  • A blood test for hCG - at this stage of pregnancy, it gives a 100% result, since the presence of chorionic gonadotropin in the blood indicates that fertilization has taken place;
  • Ultrasound - at the end of the 4th obstetric week, using high-precision equipment, you can see a thickened endometrium and a black dot on it - an attached embryo.

An embryonic ultrasound at 4 weeks is performed using a transvaginal probe. At this time, the existing pregnancy is clearly visible.

What you can see:

  • Dilated blood vessels of the endometrium, giving the embryo the ability to feed;
  • Fetal sac in the form of a black circle several millimeters in diameter;
  • The yolk sac is in the form of a small ring with a diameter of 2-3 mm.

The embryo itself will be possible to distinguish on the yolk sac in another week. Ultrasound examination at this stage of pregnancy is carried out exclusively for medical reasons - the exclusion of cystic drift, ectopic pregnancy.

Hormones at 4 weeks

Hormones at 4 weeks
Hormones at 4 weeks

Chorion (shell of the embryo) produces hCG - chorionic gonadotropin. It prevents the rejection of the embryo, which is a symbiosis of its own and alien cells for the body, produces steroids, determining the sex of the unborn child, and maintains the corpus luteum. The hCG level increases daily until 7-8 weeks of pregnancy, then it begins to decline.

Before the formation of the placenta, the corpus luteum produces progesterone, which plays an important role in the normal course of pregnancy.

Progesterone functions:

  • Ensuring the growth of the uterus;
  • Decrease in the frequency and intensity of uterine contractions, prevention of miscarriage;
  • The growth of subcutaneous tissue for nutrition of the embryo;

  • Prevention of rejection of a foreign organism;
  • Development of individual tissues of the fetus;
  • Preparing the mammary glands for breastfeeding.

The average amount of progesterone in the blood of a pregnant woman at 4 weeks is 18 nMol / L. Physical and mental stress, hormone intake are not recommended before the study.

When to see a doctor?

The visit to the doctor can be postponed for the time being if you feel normal. If the test result is positive and pulling pains, signs of early toxicosis, atypical discharge, you should consult your doctor.

Possible actions of a gynecologist with a woman's well-being at 4 obstetric months:

  • Collecting anamnesis;
  • Visual examination, examination on a gynecological chair;
  • Appointment of vitamin and mineral complexes containing, among other components, folic acid.

Signs of illness, a history of miscarriages requires specific treatment. Women who have problems with conception and who become pregnant with IVF or ICSI are under the supervision of a doctor from the first days of pregnancy.

Watch a video that will tell you why you need to do a genetic analysis, what happens in the female body, about hereditary diseases - cystic fibrosis, hemophilia, Down's syndrome and screening for chromosomal pathologies:

Pain in the abdomen and lower back at 4 weeks

Pain in the abdomen and lower back at 4 weeks
Pain in the abdomen and lower back at 4 weeks

Low-intensity pain in the lower abdomen and lower back, without abnormal discharge and an increase in body temperature is the norm at 4 weeks of pregnancy. Such sensations are caused by hormonal changes in the body, they pass quickly and without consequences. Intense pain accompanied by bloody discharge may be signs of the following pathologies:

  • cystitis, pyelonephritis - urinary disorders and hyperthermia join;
  • Constipation, flatulence;
  • Ectopic pregnancy - sensations often occur on one side;
  • The threat of termination of pregnancy or a frozen embryo - accompanied by bloody or bloody vaginal discharge;
  • Surgical pathologies (appendicitis).

The appearance of such symptoms is a reason for immediate medical attention.

Vaginal discharge at 4 weeks

Vaginal discharge at 4 weeks
Vaginal discharge at 4 weeks

Normally, at this stage of pregnancy, there should be transparent thick mucous discharge from the vagina. Attachment of a small amount of brownish discharge is allowed - a sign of egg implantation into the endometrium of the uterus. If the color of such discharge turns dark brown, they are accompanied by the appearance of abdominal pain and an unpleasant odor - this is a sign of an ectopic pregnancy, miscarriage that has begun, cervical erosion, and bacterial infection of the vagina.

Bloody discharge should not be normal at this time. Menstruation will not begin any more, since this process is regulated by the woman's hormones.

Possible causes of bloody vaginal discharge:

  • Sexual intercourse;
  • Gynecological examination in mirrors;
  • Cervical erosion;
  • The onset of spontaneous termination of pregnancy;
  • Ectopic pregnancy.

All atypical bleeding of any intensity requires immediate medical advice. In case of miscarriage, discharge may be accompanied by fever, spasmodic pain, and contain tissue particles. With an ectopic pregnancy, a woman may faint from intense pain, her skin turns pale, and dizziness is felt.

Fever and colds at 4 weeks

Fever and colds at 4 weeks
Fever and colds at 4 weeks

A slight increase in basal and general temperature up to + 37.3 ° C is the norm at this stage of pregnancy, if it is not accompanied by signs of a viral infection. The reasons for this symptom may be hormonal changes in the body, acceleration of metabolism, a decrease in the immune response, as prevention of embryo rejection.

Against the background of a decrease in immunity, a pregnant woman may develop an infectious disease at 4 weeks - ARVI, influenza, cystitis, pyelonephritis. Then the body temperature rises to + 38 ° C- + 39 ° C. In this case, there is a danger for the correct development of the embryo, the risk of miscarriage.

Prevention of colds during pregnancy:

  • Avoid crowded places;
  • Do not contact patients with infectious diseases;
  • Ventilate the premises more often;
  • Observe the mode of walking in the fresh air, sleep and rest;
  • Eat right with vitamins in the form of fresh vegetables and fruits.

Do not self-medicate colds. Only a doctor can choose the right medicines, taking into account the pregnancy.

The biggest mistake in self-medication during pregnancy is taking antibiotics. There are a limited number of antibacterial drugs available for pregnant women and week 4 is not the best time to use them. During the formation of the most important organs of the fetus, antibiotics can show a teratogenic effect, cause the appearance of deformities and developmental pathologies in the unborn child.

Nutrition at 4 weeks of gestation

The main requirements for the preparation of the diet of a pregnant woman is a balanced diet, rich in nutrients. Now you shouldn't eat canned food, fast food and semi-finished products.

The best dishes to add to the diet are vegetables and fruits, dairy and sour milk products, fatty fish - salmon, trout, salmon. It is advisable to eat your usual food, avoiding exotic dishes. Boiling in steam, and in water, stewing food is encouraged. Fried, smoked food is not included in the diet of a pregnant woman.

It is completely unacceptable to consume alcohol in any form - beer, house wine, low-alcohol cocktails. The woman and her unborn child now have a common circulatory system, and everything she eats and drinks enters the blood of the embryo.

Nutrition at 4 weeks of gestation
Nutrition at 4 weeks of gestation

Sex at week 4

Intimate relationships at this stage of pregnancy do not carry any changes. On the contrary, a psychological moment is possible associated with the absence of the need for protection and an increase in the sex drive of a pregnant woman. The exclusion of sexual contacts or their temporary restriction occurs when a woman is threatened with miscarriage, pain and bloody discharge.

If the partner has an infectious disease of the genital organs, sexual intercourse is terminated until his full recovery.

At the 4th week of pregnancy, there is an intensive division of embryonic cells, their functional distribution. The woman receives confirmation that she is pregnant and must now take a more responsible attitude towards her health.

Video about the emotional state of a woman at the 4th week of pregnancy, about how to inform the future father about pregnancy:


The author of the article: Lapikova Valentina Vladimirovna | Gynecologist, reproductologist

Education: Diploma in Obstetrics and Gynecology received at the Russian State Medical University of the Federal Agency for Healthcare and Social Development (2010). In 2013 completed postgraduate studies at N. N. N. I. Pirogova.


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