Ultrasound in the second trimester of pregnancy: timing and norms of indicators

Pregnancy’s second trimester is a thrilling and significant time for the mother and the growing child. An important procedure at this time is the ultrasound, which gives a clearer picture of the baby’s growth and development.

Doctors can examine the baby’s organs, movements, and general health with the aid of this scan. Additionally, it enables parents to see their infant in stunning detail on screen—often for the first time. Usually performed between weeks 18 and 22, the ultrasound provides valuable information about the developing fetus.

Expectant parents can feel more prepared and confident as they progress through the pregnancy if they are aware of the timing and important indicators of this ultrasound. It’s easier to go through the experience and ensure that things are going according to plan when you know what to anticipate.

Why is it necessary?

The screening process includes an ultrasound examination in the second trimester with the aim of identifying higher risks of having a child with genetic and other pathologies and anomalies. Studies that are carried out during the first and second trimesters are mandated by the Russian Ministry of Health. Women receive them at no cost during a consultation at their home.

A specialized computer program is used to process the indicators that the ultrasound diagnostics doctor receives, along with the results of a blood test that measures hormones and proteins, the levels of which may indicate potential pathologies in the child and difficulties conceiving.

Blood is tested for hCG and PAPP-A protein in the first trimester and for hCG, estriol, and alpha-fetoprotein (also known as the "triple test") in the second trimester.

The program "brings together" the data from two sources, analyzes individual risks, such as the age of the woman, the existence of unhealthy habits and chronic diseases, and information about genetic pathologies in the future mother’s and father’s families, to produce a result that shows the likelihood that a particular woman will give birth to a child who has Down syndrome, Edwards syndrome, Patau syndrome, or other incurable and even fatal pathologies.

Screening during the first trimester, which occurs between 10 and 13 weeks, is thought to be the most informative. The expectant mother can see her significantly grown baby on the ultrasound scanner monitor, learn more about the baby’s development, and confirm the child’s sex in the second study, which offers significantly less information on markers of genetic pathologies. The easiest time to determine the gender of an ultrasound is during the second trimester.

The child is not too big to cover up an overview of private areas by shrinking into a lump, nor is it too small to obscure the developed genitalia.

Peculiarities

The conditions of the scheduled follow-up ultrasound are less stringent than those of the initial screening study. It is advised that the Ministry of Health conduct an examination between 18 and 21 weeks. In actual use, these terms may change both slightly and significantly. Pregnant women are frequently sent for screening between 16 and 17 weeks; terms between 10 and 24 weeks are also fairly common and well-liked among obstetricians and gynecologists.

Not too long ago, the attending physician could not have been afraid if the results of the first screening did not warrant a second ultrasound. Women at risk, including those who are over 35 years old, have previously given birth to children with genetic disorders, and fall into other categories of expectant mothers, were required to have a second ultrasound. There is no need to be concerned if the doctor recommends a second screening exam because the second examination is now performed on all patients without exception.

During the second trimester, ultrasound is performed to determine:

• the number of children (it happens that during the first examination the second fetus is not visible and is revealed to the doctor only during the second examination);
• the position of the baby in the uterus, its estimated weight, height;
• the size of the baby"s limbs, head, abdomen separately (the development of each part of the body is of great importance for determining the proportions and characteristics of the baby"s development);

• the baby"s heart rate and the structural features of its heart;
• the structural features of the facial bones, chest, spine;
• the structural features of all important internal organs – kidneys, liver, lungs, brain);

• the amount of amniotic fluid (the waters surrounding the baby);
• the degree of maturity, thickness and location of the placenta;
• condition of the cervical canal, cervix, presence or absence of tone of the uterine walls.

It’s time to ask the doctor if the baby is a boy or a girl and who "lives in the tummy," particularly if the parents are unsure about the first ultrasound’s findings or if the baby’s gender is unknown. However, you should be aware that identifying the baby’s gender is not part of the routine examination protocol. As a result, the doctor is free to decline your request or charge you for the service. Gender determination has been formally added to the list of paid services in numerous consultations.

The actual ultrasound examination is performed through the abdominal wall, or transabdominal approach. But occasionally, the physician employs the transvaginal approach. If the mother is obese or has a thick layer of fat on her abdomen that makes it difficult to see through the peritoneum, a vaginal sensor can help obtain a clearer image of the child. Sometimes both examination techniques are applied simultaneously.

The diagnostic procedure is painless, takes about ten minutes, and is entirely safe for the mother and her unborn child.

Preparation for the examination

If the woman was advised to prepare before the first ultrasound by emptying her intestines of any accumulated gas before seeing the doctor, then there is no need to prepare in any way before the second ultrasound appointment. The results of the ultrasound will not be impacted by gas accumulations in the intestines. The intestinal loops become less noticeable as the uterus gets bigger.

Additionally, there’s no need to fill the bladder.

You can eat anything before the exam, but the woman can have a small chocolate bar right before going into the ultrasound room. Sweets will cause the tiny person inside her to react faster and start moving more actively, which will help the doctor assess the baby’s motor abilities and better examine it in various projections.

You may also bring the father of the unborn child to the second ultrasound if the diagnostician approves. On the scanner monitor, he will see something very fascinating because the fetus is now clearly visible. You can admire its profile and see its arms and legs, fingers, mouth, nose, eye sockets, and genitals. Future parents will even be able to view the baby’s appearance if the ultrasound is performed in 3D.

Following the procedure, the woman receives a research protocol containing numerous numerical values and abbreviations. During the diagnostic process, not every doctor in the consultation has the chance to explain to each prospective mother what this or that indicator means and says. You will therefore need to make sense of the jumble of letters and numbers on your own. We’ll assist you in this.

An ultrasound gives parents a unique chance to see their developing baby during the second trimester. It’s crucial for keeping an eye on the health of the unborn child and gives valuable insights into their development and the environment inside the womb.

Usually, the ultrasound is scheduled for between weeks 18 and 22 of pregnancy. In order to make sure everything is developing normally at this point, doctors look for a variety of indicators, such as the baby’s organs, measurements, and movements.

Making educated decisions about the remainder of the pregnancy is made easier for parents and healthcare professionals when they are aware of the ultrasound results. Because the baby’s progress is being closely monitored, it can also provide a sense of assurance.

Typically performed between weeks 18 and 22, ultrasounds in the second trimester of pregnancy are crucial examinations that aid in tracking the development of the developing fetus. In order to make sure everything is developing normally, doctors evaluate important indicators such as the baby’s size, heart rate, and organ development during this scan. Additionally, parents can typically learn the baby’s gender at this time.

Video on the topic

Which is better to do the 2nd screening and which tests are better to take? Answered by obstetrician-gynecologist Guzov I.I.

SECOND TRIMESTER | Screening of the 2nd trimester when it is necessary to do and norms

Ultrasound of the 2nd trimester. Timing and tasks of the second trimester ultrasound screening. Pregnancy in the CIR.