Twins are not only a big responsibility for future parents, but also a rather difficult period of pregnancy. In order to avoid any unforeseen circumstances, it is necessary to be prepared. Thus, we suggest you find out more about tween pregnancy week by week in the article.
Features of the Course of Multiple Pregnancy
In general, by Nature, a woman is supposed to bear only 1 fetus. Therefore, twins require close observation of specialists throughout pregnancy.
Women who bear two babies have a higher risk of developing anemia since their circulating fluid volume increases significantly. Their uterus increases more and faster, which means that it squeezes the neighboring organs more strongly. Therefore, with multiple pregnancies, constipation, heartburn, and shortness of breath are almost inevitable.
Also, often there are features in weight gain. If during normal pregnancy, a woman’s weight increases by 8–15 kg, with twins it can reach 15–20 kg. This can affect the vessels, the spine, and joints. Sometimes there is pain in the back and legs, as well as varicose veins.
In the duration of pregnancy, twins also have features. It would be great if a woman pregnant with twins can carry babies 36-38 weeks. However, you need to be prepared for the birth at 34-36 weeks, and sometimes even earlier.
Most often, childbirth in multiple pregnancies is performed by elective cesarean section. However, even if the birth is natural, you need to be prepared for the decision about the C-section to be made at any time. After all, the probability of complications in the birth of twins is much higher.
Children have less weight and often show signs of prematurity. However, twins have high adaptive abilities and quickly gain weight with proper care.
Twin Pregnancy Week By Week

4-8 Week
At this time, the children are still very tiny, they are just beginning to form vital organs. Determining the weight of twins by weeks can be started already from this stage, although babies weigh around 5 g. each, or even less. From 5 weeks of pregnancy, twins can be determined by ultrasound. An interesting fact is that at later dates the twins on the ultrasound scan may not be determined, since the beam of the device sees only the baby who is closer.
8-12 Week
Twins continue to grow. The babies already have a heart system, genitals, fingers, and toes. Surprisingly, you can even see the eyelids. In addition, at week 12, the intestines are already formed, and the babies begin to swallow and suck.
12-16 Week
The development of twins by weeks in this period is one of the most tangible. By the end of week 16, babies already reach up to 200 g in weight, and up to 17 cm in length. Twins can independently find their mouth with their fingers and already control the movements of the head. At this period of pregnancy, twins begin their first movements. However, these movements are so insignificant that the mother cannot feel them.
16-20 Week
The twins are almost completely formed, and their weight reaches about 300 g each. In addition, at this time, the kids begin to react to the sounds, so you can accustom the children to the father’s or mother’s voice, put on classical music, read fairy tales or poems, etc.
20-24 Week
The face continues to form – eyelashes and eyebrows are already visible. The shape of the nose becomes noticeable as well. The arrangement of twins in the stomach is traditional at this period, and the little ones themselves already know about the existence of each other.
24-28 Week
Development of the fetus from 24 to 28 weeks for twins is especially important because at the end of 28 weeks the babies become viable. During this period, the formation of the lungs occurs, which means that even if children are born ahead of time – their chances of life increase significantly.
Tween Pregnancy Week By Week: The Third Trimester
28-32 Week
The weight is around 1.5 kg, and the height is up to 40 cm. In addition, the fluff hair continues to grow, and the twins already have their own sleep cycle.
32-36 Week
The weight and height of babies are not much different from a child with a single pregnancy. In addition, the lungs of the twins are developing much faster, probably preparing quickly for independent life.
36-40 Week
During pregnancy with twins at 37–40 weeks, babies are considered to be full-term and ready to be born. Of course, the weight of twins is usually less than that of a child in a single pregnancy, but at this time it is no longer a threat to life and health.
Features of Twin Pregnancy
As a rule, all future moms are interested in how they will give birth (naturally or through C-section) and at how many weeks. Of course, multiple pregnancies can be accompanied by some complications and the birth of twins earlier than expected is also possible, but with a high level of development of medicine, this should not cause serious concerns.
Nevertheless, there are a number of recommendations, which should still be followed. Ask your doctor about these recommendations.
Also, many questions arise about missed miscarriage. As a rule, if the fetus dies in the first trimester, then there is a high probability of a successful outcome for the second child. But if one of the babies dies in the II-III trimester, then, unfortunately, it is likely that the second child will die.

Born in Belarus, 1985, a pedagogue and family psychologist, mother. Taking part in procedures of social adaptation of the foster children in new families. Since 2015 is a chief editor of the motherhow.com project, selecting the best and up-to-date material for those, who are planning, expecting, and already having babies.