Twelfth week of pregnancy : can you feel your baby's movements yet? What is the purpose of a 12-week ultrasound, and why is it sometimes called a "genetic" ultrasound? Does a 3D ultrasound reveal the fetus's gender ? What are the prenatal tests and what are the recommended tests for the 12th week of pregnancy ? What other tests are recommended at this time?
More and more moms are starting to check the size of the abdomen and want to know what the baby looks and behaves in the 12th week of pregnancy. It is getting closer and closer to the end of the first trimester - the 12th week of pregnancy means that ultrasound can be performed through the abdominal wall. In some women, such troublesome ailments as frequent pressure on the bladder or nausea may slowly subside. An important element of the obligatory 12st trimester ultrasound is the measurement of the translucency of the fetal nape. In addition, in the XNUMXth week of pregnancy, an assessment of the risk of depression is recommended.
Week 12: how is your pregnancy going? The course of pregnancy at week 12
The 12th week of pregnancy marks the end of the period of highest risk of miscarriage – approximately 80% of all miscarriages occur in the first 12 weeks. The longer the pregnancy, the lower the risk. To ensure the fetus is developing properly, it's worth remembering the tests recommended at this time – 12 weeks is the appropriate time for a mandatory first-trimester ultrasound , as well as the second general urine test during pregnancy (which should be performed between 11,0 and 14,0 weeks). It's also worth undergoing the first depression screening test, which involves the patient completing a questionnaire.
During the XNUMXst trimester ultrasound, the doctor confirms the pregnancy age. This is especially important if you have PCOS (polycystic ovary syndrome) or have problems with your monthly periods. The gestational age, determined solely by the date of the last menstrual period, may, in the above-mentioned cases, lead to a discrepancy in the calculations between the date of birth and the actual age of pregnancy.
12 weeks of pregnancy: ultrasound through the abdomen
Until now, the examination was performed vaginally, which wasn't very comfortable for the expectant mother. From around week 12, transabdominal ultrasound can be performed . This allows the patient to lie comfortably during the examination and invite a partner or other loved one to the examination room. In some cases, transvaginal ultrasound is still performed, for example, to assess the length of the cervix.
An ultrasound examines the internal organs and examines the outline of the fetus, also checking the circumference of different parts of the body. A much clearer, spatial image of the baby in the 12th week of pregnancy can be seen on the 3D ultrasound, which allows the doctor to assess the shape of the head, as well as the development of the limbs and spine.
Turning on the Doppler function during an ultrasound at 12 weeks of pregnancy allows you to check blood flow in vessels, such as the uterine arteries or the middle cerebral artery.
Doppler examination is usually a great experience for future parents, as it allows them to hear the fetal heartbeat.
12th week of pregnancy on 3D ultrasound: sex of the baby
From the 12th week of pregnancy, you can attempt to determine the baby's gender with an ultrasound. The internal and external genitalia are already developed, but still very small and therefore difficult to see. Much also depends on the fetus's position during the examination. This means that a 12-week ultrasound won't be 100% certain whether it's a boy or a girl. A 3D ultrasound offers a better chance of determining the baby's gender. Thanks to more advanced equipment, a three-dimensional image of the fetus can be seen on the screen during this examination in color. Will this allow for determining the gender at 12 weeks of pregnancy? It's more likely, but you should always consider that the baby will cover itself or that the genitals simply won't be clearly visible.
In addition to 3D ultrasound at 12 weeks of pregnancy, 4D ultrasound is also used to determine gender. This allows the three-dimensional image to be transformed from static to allow for observation of the baby's (fetal) movements . These ultrasound methods are not available everywhere and may involve additional costs, as may the free DNA test from the mother's blood, performed for this purpose. Sometimes, it's enough to wait a little longer for a "regular" (2D) ultrasound to determine gender with greater certainty.
Baby at 12 weeks of pregnancy
A baby at 12 weeks of pregnancy – the fetus – is between 43 mm and 53 mm long (CRL) , measured from the buttocks to the top of the skull (the legs are still curled up, so it would be difficult to measure them). At the middle of the twelfth week of pregnancy, it weighs about 58 g.
Around the 12th week of pregnancy, the baby, the fetus, is properly formed on the outside - it already has all the parts of its body. Much more is happening inside the new organism.
In a child in the 12th week of pregnancy:
- neurons and synapses form in the brain,
- the pituitary gland produces hormones,
- the spine hardens,
- the first movements in the digestive system,
- the pancreas starts producing insulin and the kidneys start producing urine,
- the bone marrow produces blood cells.
12 weeks pregnant: baby movements
In the 12th week of pregnancy, the fetus moves freely in the amniotic sac - it still has a lot of space surrounded by amniotic fluid. The umbilical cord connects it to the placenta "built-in" into the uterine wall, from where it receives oxygen and all the necessary nutrients. He can open and close his mouth as well as wrinkle his forehead.
Regarding the frequently asked question about the 12th week of pregnancy, the baby's movements are still faint, although they can sometimes be seen on ultrasound. However, it's definitely too early for the expectant mother to feel them.
Prenatal testing at week 12
Prenatal testing is performed to assess the anatomy of the fetus and check for early structural defects. As for the first and second trimesters, they are carried out when the baby - fetus - reaches 45 mm of CRL, which usually falls on week 12 of pregnancy.
Contrary to popular belief, prenatal tests at this stage are usually not invasive and are not associated with a risk for the future mother and child. These include, first of all, the 12st trimester ultrasound performed at week 2 (or within the next 13,6 weeks - up to XNUMX weeks), often called "genetic ultrasound". Its purpose - apart from assessing the size of the fetus, determining the duration of pregnancy and the date of delivery - is to examine individual internal organs.
During a first-trimester ultrasound, the doctor checks nuchal translucency (NT ), which is the distance between the skin and subcutaneous tissue of the fetus around the neck . Excessive translucency may indicate the aforementioned chromosomal abnormalities. This measurement is reliable when the fetal crown-rump length (CRL) is between 45 and 84 mm – at 12 weeks, this is usually closer to the lower limit.
Other non-invasive prenatal tests, such as the PAPP test, although recommended, are not reimbursed for all future mothers.
12th week: prenatal tests for women over 35
For women over 35, reimbursable prenatal tests include a combined fetal ultrasound test, which measures the levels of two substances: pregnancy-associated protein A (PAPP-A) and free beta hCG (a beta subunit of human chorionic gonadotropin) in the mother's blood . If there is a higher risk of genetic defects in the fetus, chorionic villus sampling (CVS) is recommended. This is the earliest invasive prenatal test (performed between 11,0 and 13,6 weeks) and is also reimbursed by the National Health Fund for expectant mothers over 35. A CVS also allows for determining the baby's gender.
However, if the PAPP-A test result is abnormal, chorionic villus sampling is rarely performed. Amniocentesis is performed much more often (after 15,0 weeks). Both chorionic villus sampling and amniocentesis are invasive methods with the risk of miscarriage or infection.
The well-being of the future mother in the 12th week of pregnancy
The uterus begins to move upward and forward, requiring more and more space in the abdomen of a woman in her 12th week of pregnancy. This shift can provide some relief from pressure on the bladder and the need for constant bathroom visits. However, pressure on the intestines can also lead to problems with elimination and gas. Some expectant mothers confuse the baby's movements, which are not felt yet at 12 weeks, with these changes in the abdomen. In terms of size, the uterus may already resemble a melon.
Dizziness and blood pressure problems are the result of a significant amount of blood flowing back into the placenta. Regarding belly size at 12 weeks of pregnancy, first-time mothers generally have only a slightly firm, rounded lower belly. Repeat mothers tend to have a larger belly and a less defined waistline during pregnancy.
Besides a changing belly size, characteristic symptoms include sensitivity to odors and heartburn. Nausea persists for most of pregnancy for some women, but for some expectant mothers, it ends around week 12.
Consultation:
Ph.D. n. med. prof. IMID Tadeusz Issat - Head of the Obstetrics and Gynecology Clinic at the Institute of Mother and Child;
Maria Krowicka-Wasyl – resident physician during specialization in gynecology and obstetrics, Clinic of Obstetrics and Gynecology at the Institute of Mother and Child.
Źródła:
Fetal Size and Dating: Charts Recommended for Clinical Obstetric Practice, ULTRASOUND, August 2009, Volume 17, No. 3
Estimating Fetal Gestational Age, Radiology Key
Fetal Development, Perinatology.com
