Twins weekly weekly pregnancy
Nature has provided only one version of uncomplicated pregnancy - bearing one fetus. Therefore, the situation when two children develop in the mother’s tummy is always considered difficult. And even if a woman feels well, doctors will treat her more closely, more sensitively, as a patient with a complicated pregnancy. Unfortunately, future mothers of just two children do not have much information about the development of the fetuses - all medical sites, manuals and articles mainly tell about the development of a single fetus.
But twins pregnancy proceeds differently. This material will provide a weekly review of multiple pregnancies.
First month - conception and implantation.
The first week of pregnancy in obstetrics is considered to be the week when a woman is still going monthly and conception has not yet happened. A woman can conceive a child only during the fertile period, when the egg leaves the follicle, ovulation occurs. On this day, which usually falls in the middle of the menstrual cycle, and also within 24-36 hours after ovulation, conception may theoretically occur. Thus, the woman on the day of conception is already at 2 weeks of pregnancy.
Conception of twins has its own characteristics. Typically, nature involves the maturation of only one egg, the growth of the rest in the ovaries is suppressed at the hormonal level. But sometimes the streamlined natural mechanism gives a "failure", and two ova come out into the fallopian tube on the day of ovulation. In this case, both can be fertilized, and then dyzygotic twins or twins will be born. They will develop in one maternal womb, but each person’s genetic set will have their own, and such children will not resemble each other. Each baby will have its own placenta, they may well be of different sexes.
It is possible that one of these dizygotic twins will be blond, and the second - a brunette. At birth, they will differ significantly in height and weight, they will have different characters, temperaments, talents and inclinations, tastes and preferences.
Monozygous twins are born as a result of fertilization of one egg. After the paternal and maternal germ cells exchange genetic information, one zygote is formed - an independent cell with its own set of DNA. The reasons for which the zygote suddenly doubles are unknown to science, but its splitting into two separate zygotes occurs already during the first two days after fertilization.
If this separation occurs within the first three days, then the twins will each have their own fetal membranes and placenta, but if the separation occurs later, then twins are formed, which will be fed from the same placenta. If the separation occurs late, two weeks after fertilization, the probability of formation of conjoined Siamese twins is high.
Gemini, since they originate from the initially single zygote, have an identical genetic set, being an exact copy of each other. Such children have the same sex, and if they inherit a genetic disease, then it is inherent in both of them.
At 3-4 weeks of pregnancy, while splitting or two separate fetal eggs fall into the uterus, implantation occurs. The embryos stick to the endometrium, are introduced into it by the chorionic villi and begin to receive nutrition from the maternal blood. Fetal structures begin to form.
In this case, twins or identical twins acquire another classification.
- Bichalial diamnotic - children, each having its own fetal membranes and its own chorion, which then becomes two separate placentas. Such a pregnancy is considered the safest and most optimal, most often this happens when twins are conceived from two different eggs, and only in 30% of cases - when multiple-twin twins are conceived.
- Monochorial diamniotichesky - children who have a single placenta for two, but each has their own fetal bladder. This happens in 60% of cases when conceiving identical twins and almost never when conceiving twins.
- Monochorial monoamniotic - children who have the same placenta, different umbilical cords, which are attached to it. The babies are inside one for two gestational eggs.
By the end of the fourth week of pregnancy, these features are usually already acquired. Only mom does not know anything about it. The end of 4 weeks is the waiting time for the next menstruation, which never comes. And the mother’s head is still busy diagnosing and confirming pregnancy. The main surprise - twins, while not obvious.
Subtleties of diagnosis
In the early stages of the diagnosis of multiple pregnancy is somewhat difficult. The only thing that can indirectly indicate that in the womb is not one baby, but two - indicators of hCG. This hormone is produced by chorionic villi after implantation, and its concentration increases every two days. Therefore, a blood test for human chorionic gonadotropin, carried out on the day of the delay, a couple of days before or after the delay can theoretically show double values relative to the norm, but only under the condition that the twins are dichorial.
In this case, the double efforts of the two chorions will lead to double the values of the hormone, which is necessary to maintain pregnancy.
Twins, who have one chorion, will not be "visible" by analyzes of hCG. And it will be possible to determine them only after 8-9 weeks of pregnancy on ultrasound - an ultrasound examination will show two embryos.
According to the home test strip, a woman at 4 weeks of pregnancy, alas, can only determine the fact of having an “interesting position”, but not the number of fetuses. The signs of early pregnancy will also not differ from those of a singleton pregnancy.
The development of the fruits in different terms
So, conception and fertilization took place. The woman did the test the first week after the delay and found out that she was pregnant. But inside are already in full swing important processes that can be tracked week by week.
5 week
From the first day of delay of the next menstruation the woman begins the fifth week. The embryogenesis of the fruits is in full swing - both babies simultaneously have the processes of laying the heart, kidneys, liver, there is a chord. By the end of the week, you can visit the ultrasound room and during the examination with a transvaginal sensor, you can hear the heartbeat. Two hearts will beat, but for the time being it will be difficult to hear, because the heartbeat and one child on such a short time are very irregular, confused.
If the twins are dichorial and diamniotic, an experienced ultrasound doctor will be able to detect two fetal eggs. Identical twins still prefer to remain secret - you can see only one fertilized egg.
6 week
"Interesting position" is already obvious to mom - she did a test or donated blood for hCG, received positive results. Fruit growth is about 4 mm. The formation of the organs of the immune system begins, and the thymus gland of each of the twins is being laid.In children, pens are formed, which so far look like fins, dark dots are formed on the sides of the head - these are future eyes, and small dents are future ears. Embryos are still immobile.
7 week
Kids are growing rapidly. This week, their growth is close to 7-8 mm, weight - to one and a half grams. The formation of the nervous system begins. New nerve fibers make the embryos move reflexively. The formation of the eyes and optic nerves began. A single gut in each of the fruits was divided into sections, forming the digestive tract. In embryos, regardless of whether they are twins or twins, the pancreas begins to produce its own insulin at the same time. The laying of the external genital organs begins. Embryos can bend and unbend.
This week may begin a strong toxicosis, because uteroplacental blood flow starts. Twins with a single placenta for two this week may begin to grow at a different pace.
If before that they increased in height and weight about the same, now one of the children can “pick up” more food and oxygen than the second, and soon in such a “duet” there will be differences in terms of height and weight.
8 week
The neural tubes of the children were divided into the brain and spinal cord. The twins learned to move their heads. The height is within 2-2.3 cm, tiny faces are formed, legs are formed, which are still shorter than the arms, but there are already knee joints on these tiny legs.
Week 9
Kids begin to differ in size from their peers, who in a single copy are bearing other pregnant women. The difference in height is now about 2 millimeters, and in weight - a whole gram. Each of the twins now weighs about 5 grams with a growth of 2.8 centimeters.
Toddlers are starting to look like human beings. Fetal tails are reduced, each has two arms, two legs, a large head. The organ laying period is over, and this week ends the period of organogenesis. The last are the rudiments of the teeth.
Children learned to open their mouths, clench their hands into fists. Each baby produces its own blood cells. The placenta becomes more complete and assumes all the responsibilities of transporting oxygen and nutrients to children and taking metabolic products from them. Needless to say, two placentas cope with such work better than one.
10 week
Your twins are no longer embryos, now babies are the fruits, and they will remain like this until the birth. Now they have mastered the new movements and are learning to move their hands. Toddlers begin to swallow the amniotic fluid, writing. Both have necks formed, now each of your children can turn their heads to the sides.
Faces become more human: there are lips, eyelids, nose and auricles. Hair begins to grow on the head, and thin, colorless lanugo hairs on the body, which together with cheese grease will protect the skin until the skin becomes more durable, four-layer.
The process of hardening of the bones begins. The need for calcium increases significantly.
11 week
So far, the lag behind single-peer peers is not so significant in growth. There are still babies, of which there are two in the womb, 0.2 cm less than single fetuses in a singleton pregnancy, but here in weight the difference is already significant: Each of the twins weighs about 12 grams now, while single fruits have already reached a weight of 14.5-15 grams.
Developmental defects will no longer threaten, the most dangerous time is left behind. Starts the growth and formation of the functions of the internal organs - systemogenesis. On ultrasound, it is already clearly visible which of the fruits is larger. Gender is still difficult to consider, the process of formation of external organs continues.
Kids learned to grab, suck, swallow. These reflexes are considered major. The eyes move from the side surfaces of the heads to the center of the face. Both twins taught to yawn.
12 week
Your crumbs are already weighing about 20 grams, which is less than the weight of one fetus during singleton pregnancy, about 2 grams. Many begin to actively grow belly. This week, most people undergo prenatal screening for congenital chromosomal abnormalities. The process of equalizing the proportions of the bodies of children begins: the heads will now grow more slowly than the rest of the bodies. Kids taught to distinguish between the tastes of the amniotic fluid, and they already like sweets eaten by mom much more than garlic. Completed the formation of genitals.
Under certain efforts on the part of the doctor, it is already possible to determine the sex of children (identical, as we remember, have the same sex). The accuracy of determining the sex at this time is low, it is better to wait a little longer.
13 week
The first trimester of pregnancy ends. Together with him, toxicosis is reduced if it was. Kids are very thin, red and shriveled, like dried fruits. There is no subcutaneous fatty tissue, and therefore all the blood vessels without exception are visible through the skin.
Kids begin to hear, or rather, perceive vibrations of sound waves. Until full hearing is still far. The brain matter grows, children begin to "grow wiser." Now kids learned to hug. Everyone can hug themselves by the shoulders, and if the twins are identical, then they can hug each other.
14-15 week
The size of the fruits now with each week will increasingly differ from singleton pregnancy, but the growth will be individual. Now all the forces of the children will be thrown on the growth and weight gain, the weight gain of the mother will also grow rapidly, the size of the abdomen during multiple pregnancies is already noticeably different from pregnant with one baby. Tummy growth will be accompanied by different sensations.
The children had fingerprints, and even the absolutely identical identical twins had different prints. By the end of the 15th week, the first gyrus is formed in each brain.
16-17 week
The weight of each of the twins exceeded 120 grams, the height exceeded 14 centimeters. Kids learned to move their eyes under closed eyelids, they have formed eyelashes. All muscles are formed and sufficiently developed. From this date, you can accurately determine the sex of children on ultrasound. The size of babies almost reached the size of the placenta and somewhat exceeded it. The production of subcutaneous fat begins. On ultrasound, it is already possible to catch the external similarity of the babies to their parents - the facial features become individual.
If the pregnancy is not the first, you can clearly feel the movement.
18-19 week
During this period, primiparous women with multiple pregnancies begin to feel the movement of the fruit. The bones are hard enough, mineralization is almost complete. Now they will only grow. By the end of 19 weeks, each of the children can reach a weight of 270 grams with a growth of 21-23 centimeters. The size of the mother's belly is already impressive, noticeable to everyone.
From the current time children start to hear fully, like all people, but with the amendment that they are still in the aquatic environment. You can already read them and sing lullabies.
20-21 weeks
The middle of pregnancy is passed, you can start the countdown to birth. Children weigh over 300 grams. The collection of subcutaneous fat continues, and therefore the pathological thinness gradually disappears. The skin becomes more durable, begins the process of falling lanugo. In the cerebral cortex of children formed the center responsible for the perception of speech.
22-23 week
From this period, childbirth is considered childbirth, not late miscarriage, the probability of survival will be, but so far very insignificant, because the weight of children is not close to 500 grams, as in singleton pregnancy. And a baby born will have about 14% chance of survival, whereas twins born in this period have only about 6% chance of survival.
Completion of the formation of the spines. The sebaceous and sweat glands of each fruit began to function.
24-25 week
The weight of twins for the first time overcomes the mark of 500 grams.The skin begins to smooth out, get rid of wrinkles and red. The process of maturation of the lung tissue begins, the alveoli begin to produce a surfactant - a substance without which the independent breathing of children after birth will be impossible. Almost until the birth will go the process of maturation of the lung tissue. Started the production of melanin. Children have dreams, while, according to scientists, most of the time, babies are in a phase of REM sleep, in which dreams just come.
26-27 week
The second trimester ends and the third begins. The pituitary glands of the twins begin to produce growth hormones. In boys, regardless of whether they are identical or fraternal, the testicles begin to descend from the abdominal cavity into the scrotum. Improved visual function, kids begin to train the blinking reflex. Those born during this period survive in 65-70% of cases.
28-29 week
The third trimester is the most alarming for mothers with multiple pregnancies. Carrying two children is twice as difficult as carrying one, even though their weight and height are somewhat different from single fruits. By this time the average weight of one of the two fruits is close to 1 kilogram 100 grams. The stomachs of moms are already large, often you can not see their own legs.
In children, the cilia are lengthened, the cheeks are rounded. The optic nerve begins to act - if a bright light is directed at the woman's abdomen, the children will begin to turn away from the light. The survival rate of babies in case of their birth is about 85-93%. The formation of all parts of the brain is completed. At 28 weeks, women with multiple pregnancies go on maternity leave.
30-31 week
Babies become very crowded in the uterus. They took a bending position, leading the legs to the abdomen, pushing the arms and bending their heads to the chest. Hair, if they are destined to be dark on the genetic program, begin to darken. Increases the mass of the brain. Children reach 1.5 kilograms, at the same time, the difference in monochorial twins is already significant - one kid can weigh about 1800 grams, and the second - only 1300. All is individual.
In the body, oxytocin begins to be produced in small quantities, its accumulation will form a generic dominant - labor will begin at the right time. Even if it happens now, the forecasts for kids are quite favorable.
32-33 week
Kids continue to gain weight, and the mother's body is actively preparing for childbirth. Training contractions intensify, oxytocin and prolactin are produced. Kids begin to move less, because they are already very closely. From this date of delivery you can wait at any time.
34-35 week
The estimated fetal weight calculator for fetometry data for moms expecting twins no longer works - fetometry is not always measured accurately, and fetus weight comes depending on the state of the placenta, such as multiple pregnancies, and a host of other factors, among which heredity is not the least.
According to reviews, it is in this period that childbirth often occurs. especially if the cervix, according to the gynecological examination, is already short, the backache regularly hurts, the mucus plug has come off, and water has begun to leak. A woman should be ready for any eventuality.
The placenta begins to age. The weight of the kids by the end of 35 weeks can reach 2.5 kilograms. The lung continues to accumulate surfactant.
36-37 week
With a weight of about 2.7 kg, about half of all twins are born at this time. From the 37th week, children are considered full-term, and therefore there is nothing wrong with giving birth at this time. The toenails and arms continue to grow in children, the amount of amniotic fluid decreases. The weight gain of each of their twins is about 50 grams per day.
From this time on, the sense organs of the babies begin to tune in to the coming into our world, because the environment in which they are destined to fall is significantly different from the one in which they now live. Adaptive mechanisms provided by nature are activated.
38-40 weeks
If you brought the babies to the last half of the ninth month of pregnancy, we can say that you were lucky. According to statistics, most of the birth takes place at 37-38 weeks, about a third - at 38-39 weeks. Up to 40 weeks, multiple pregnancies are very rare. The weight of babies exceeded 3 kilograms, and there should be no fear - full-term babies, ready for birth.
All internal organs of twins work harmoniously, in concert. And only the lungs are still in readiness - the babies will begin to breathe after birth.
Because of the tightness inside the womb, children begin to experience stress as they approach week 39. This contributes to the development of adrenaline, which at the hormonal level also helps the mother's body to prepare for childbirth.
Right now, before childbirth, it is more important than ever to monitor the movements, to prevent the development of hypoxia - the placenta or one for two of the placenta is already significantly depleted, and therefore oxygen starvation at this period is not uncommon.
Particularly noteworthy is the choice of tactics of delivery. If the pregnancy occurred naturally, proceeded without significant complications, childbirth can be natural, and this will be correct. But the twins after IVF, the presentation of one of the fruits, which is to be born first, not with the head, but with the pelvis to exit the uterus, any complications during the long nine months - all these are reasons for prescribing a cesarean section. If it is shown, then it is carried out with a multiple pregnancy at 38-39 weeks (for single-pregnancy, at 39 weeks exactly).
The expectant mother needs to understand the recommendations of the doctors throughout the entire period of gestation.
In pregnancy, twins more often have to pass general tests, because the load on the kidneys, heart and lungs of the mother is double. More often it is necessary to visit the doctor and in the third trimester. And this, too, should not be embarrassing - since multiple pregnancies are considered difficult in any case, the order of its management is also special. But the joy is double.
About pregnancy twins, see the following video.