Normally, a woman carries an unborn child for 40 weeks, which is 10 obstetric months of 28 days. During this period, the embryo makes a long and difficult journey, developing from two parental cells into an independent organism. Among the total duration of pregnancy, experts have identified the most responsible and at the same time critical periods of fetal development.
Stages of intrauterine growth
Obstetricians divide the childbearing period into two phases: embryonic and fetal. The first begins from the moment of fertilization and ends at a period of 8 weeks, amounting to a total of 2 months. In the stage of embryonic development of the fetus, the following periods are distinguished:
- Blastogenesis - lasts from the moment of the fusion of the female and male gametes until the 2nd week of pregnancy. At this time, the diploid cell moves through the fallopian tubes to the uterus, after which it is introduced into its mucous membrane.
- Embryogenesis - is the period from 2 to 8 weeks of gestation, during whichthe formation of the placenta and the rudiments of organs occurs.
After two obstetric months, the fetal period begins, which will last until childbirth. Since then, the embryo is considered a fetus. An important feature of this time is organogenesis - the formation and development of all organs and systems of the body.
The following stages are distinguished in the fetal period:
- early (12–28 weeks) – organs are already formed, now their cells are differentiating, i.e. changing their properties;
- late (from 28 weeks to the date of birth) - the growth of organ tissues continues, the subcutaneous fat layer of the skin is formed.
The first trimester (up to 13 weeks) is the main critical period for fetal development.
Obstetric period 2-3 weeks
Most women do not even know about their "interesting" position at this time, and the fetus has the first difficulties on the way to life. A little more than a week has passed since conception, and the diploid cell moves through the fallopian tubes to the uterus. Obstacles may arise on its way: adhesions or insufficient activity of the ciliated epithelium. In this case, it becomes impossible for the embryo to enter the uterine cavity, which forces it to attach itself to the wall of the fallopian tube. An abnormal tubal pregnancy develops.
Even if nothing prevents the embryo from advancing, it must enter the uterus at the right time. With a slow path, an ectopic pregnancy will develop, and with an accelerated one, most likely, it will dieegg due to unavailability for implantation.
Let's say the embryo successfully traveled through the fallopian tubes and reached the uterine cavity at the right time. Now the fertilized egg should attach to the wall of the organ. For this, it is necessary that the uterus has a he althy epithelium, and the embryo itself is strong enough. At this stage, natural selection occurs: if the embryo is too weak or has developmental pathologies, the mother's body rejects it.
What factors adversely affect embryo implantation?
The critical periods of fetal development begin almost immediately after fertilization. The newly formed embryo is very sensitive to environmental factors and the state of the mother's body. Experts identify the following reasons that affect the process of implantation of the fetal egg:
- individual features of the structure of the uterus;
- adhesions from internal genital surgery;
- tumors of the uterus and appendages;
- severe psycho-emotional state;
- physical activity, overwork;
- alcohol and drug use, smoking;
- taking certain medications;
- endometrial diseases.
Women with a history of abortions, miscarriages, ectopic pregnancies are at risk.
Critical periods of intrauterine development of the fetus require special care from the expectant mother. If the pregnancy was not planned, at this time there is little that can be done without knowing about your situation. Otherwise, a woman should carefully prepare for conception:undergo an examination, cure existing diseases of the genitourinary system, do not burden yourself with unnecessary work and take care of emotional stability and comfort.
Risks at 4-7 weeks
The embryo successfully attached to the wall of the uterus and continued its development. The two germ layers will form the fetus and placenta. It would seem that the most difficult stage in the life of the embryo is behind, but no. Critical periods in the development of the embryo and fetus reappear at the obstetric period of 4–7 weeks. The mother-to-be is already aware of her situation.
There is an active development of the embryo: the beginnings of organs and systems are formed. At this stage, the embryo is very sensitive to the external environment, the risk of developmental pathology is high. A pregnant woman should carefully listen to the advice and warnings of doctors and take care of herself: even a mild cold can call into question the bearing of a child.
Critical period 8-12 weeks
At this time, the influence of external factors on the development of the embryo is one of the main dangers. Meanwhile, changes in the mother's body are also important, which is actively tuned to bear the fetus. Formed after ovulation, the corpus luteum produces progesterone, which contributes to the development of pregnancy. By week 12, it "transfers" its functions to the placenta. This is a very risky moment, because the amount of the hormone may not be enough for further gestation. By registering with a gynecologist, this is easy to avoid: with the help of laboratory tests, progesterone levelskept under control.
For the formation of the placenta, it is important to lead a he althy lifestyle, eat a balanced diet. Take any medication only with the permission of a doctor and under his supervision.
Risk factors in the first trimester
The main critical periods of intrauterine development of the fetus by months fall on the first trimester. At the initial stage, both the embryo and the woman in the role of mother are weak. Any external influence calls into question the life of the embryo. In order not to put the pregnancy at risk once again, doctors recommend to beware:
- Taking medication - the contents of the first aid kit will have to be carefully reviewed. For example, only paracetamol is allowed as an antipyretic and analgesic, and you should forget about acetylsalicylic acid, as well as about preparations based on it (analgin, aspirin). As an antispasmodic, use no-shpu (drotaverine). Among antibiotics, only penicillins are allowed.
- Medicinal herbs and traditional medicine - most medicinal fees, teas are prohibited during pregnancy and lactation. Before using such products, it is better to consult a doctor.
- Stress, psycho-emotional disorders - the state of the mother directly affects the child, which is most dangerous in the first months of pregnancy.
- Physical activity - do not exhaust yourself at work or carry heavy things. The expectant mother needs rest and reasonable physical activity;
- usealcohol, drugs, smoking - the toxic effects of poisons cause serious pathologies in the development of the embryo.
- Infectious diseases - any virus can seriously harm the fetus.
Critical periods in the development of the embryo and fetus require special care from the mother. If you do not neglect the doctor's recommendations and take care of yourself, reasonably limiting everything harmful and dangerous, then the most difficult first months of pregnancy will be successful for both the mother and the child.
Term 18–22 weeks
What are the critical periods of fetal development after the first trimester? The fifth or sixth month of pregnancy (18–22 weeks of gestation) is considered no less responsible. During this period, the uterus is actively growing, accelerating the pace by about 2 times. Diseases of the mother are no longer so dangerous for the child, but still undesirable. The worst thing in this period is to catch infectious STDs (herpes, toxoplasmosis, chlamydia, ureaplasmosis). However, this happens quite rarely, especially if a woman has only one permanent sexual partner.
The period is risky for women with isthmic-cervical insufficiency (ICI). This is a condition in which the cervix and isthmus cannot cope with the increasing load on them. As a result, premature disclosure occurs, which often leads to spontaneous miscarriages. However, if a woman is under the supervision of a doctor, then the pathology is diagnosed in time. A mini-operation is performed: a suture is placed on the cervix under local anesthesia. This isallows you to carry the baby to the full term of pregnancy.
Critical periods of fetal development between 18-22 weeks of gestation require careful medical monitoring. A woman still needs to protect herself from infections, physical exertion and stress. But this time is no longer so dangerous for the baby, and if the expectant mother is responsible for visiting the gynecologist, then it is easy to survive without consequences for the he alth of the fetus.
Risks in the eighth month of pregnancy
At a period of 28–32 weeks, the next critical periods of fetal development begin. Obstetrics notes that this time is no less important for the he alth of the child. The danger is a premature birth process or fading of pregnancy, which usually occurs due to hormonal disorders in the mother's body. Complications such as placental abruption, late toxicosis and placental insufficiency are also possible. All this can lead to the death of the fetus before delivery or a stop in its development.
If a woman has a history of miscarriage, the monitoring of pregnancy maintenance should be carried out especially carefully. There is not much time left ahead, so every effort should be made to bring the baby to at least 38 weeks. Obstetric hospitalization is often recommended.
Individual critical deadlines
The main critical periods of fetal development by weeks of gestation were discussed above. It is during these periods that most often there are complex situations that threaten life and he alth.embryo. But each organism is individual, so doctors identify other dangerous periods of pregnancy. These include weeks during which:
- had a miscarriage or had an abortion;
- there was a risk of miscarriage in the woman's previous pregnancies;
- there was an excessive physical or psycho-emotional stress;
- women had periods after conception.
This also includes the period after the expectant mother has had the disease.
What you need to know about the "dangerous" terms of pregnancy?
If the doctor has identified a woman at risk, during critical periods, bed rest and sexual rest should be adhered to, or even carried out in an obstetric hospital under round-the-clock supervision of specialists. If at least one of the alarming symptoms occurs, you should immediately consult a doctor:
- pain in the sacrum, lower abdomen;
- vaginal discharge (spotting, bloody, brown);
- suspicion of the disappearance of signs of pregnancy;
- lack of fetal movement or activity in last trimester;
- discharge of amniotic fluid.
How to successfully survive critical deadlines?
Critical periods of fetal development and their characteristics warn the expectant mother about possible risks and factors of their occurrence. Having learned about pregnancy and deciding to keep it, you should responsibly approach the pace of your life. Avoiding trouble is much easier if a woman regularlyvisits a doctor, fully eats and rests. All the hard work will have to be entrusted to other family members, unloading your day to the maximum. You will also need to protect yourself from harmful factors (sources of infections, useless and dangerous products, toxic substances).
The critical periods of fetal development are the most dangerous time during which the embryo is most susceptible to environmental influences. At these times, failures in the maternal body also occur, which often lead to miscarriage or fading of pregnancy. Do not brush aside the "dangerous" periods. Fulfilling all the prescriptions of doctors and protecting herself in these difficult weeks, a woman will not only successfully survive them, but also significantly increase the chances of giving birth to a strong and he althy baby on time.
