This is an automatically translated article.
The article is professionally consulted by Master, Doctor Ly Thi Thanh Nha - Department of Obstetrics and Gynecology - Vinmec International General Hospital Da Nang. Doctor Nha has strengths and experience in fetal malformation ultrasound, 3D, 4D fetal ultrasound.In the 4th month, in addition to ultrasound to screen for some malformations, knowing the gestational age, parents also need to pay attention to the length and weight of the fetus to have a reasonable care and rest plan.
1. How to calculate gestational age based on ultrasound?
Determining the gestational age is very important during the "9 months and 10 days", especially in the case of premature birth or pregnancy beyond the due date.If in the past, fetal ultrasound techniques have not really developed and people have not paid attention to pregnancy health care, medical staff can only rely on and exploit the history and physical examination. Nowadays, fetal ultrasound is considered an effective aid in determining the age and weight of the fetus, helping pregnant women plan the best pregnancy care.
In fact, if the pregnancy ultrasound is done at the right time, the determination of gestational age will be much more accurate than based on the last menstrual period.
Determining the exact age and weight of the fetus will make an important contribution in monitoring and diagnosing cases of intrauterine growth retardation or abnormalities in development. During pregnancy, each pregnant woman should have only 1 due date and 1 consistent gestational age.
The criteria for determining gestational age on ultrasound as recommended by the Society of Obstetrics and Gynecology of Canada (SOGC) in 2014 are as follows:
| Tiêu chuẩn | Mô tả |
|---|---|
| Mặt cắt dọc giữa | Thấy rõ mặt nghiêng của mặt (midline facial profile), cột sống, mông của thai chỉ nhi trên một hình ảnh trọn vẹn |
| Tư thế trung gian | Nên có khoảng dịch giữa cằm và ngực, đường thẳng qua mặt nghiêng sẽ cắt đường CRL trước điểm cực mông |
| Nằm ngang | Thai nhi nên nằm ngang, đường đo CRL nên hợp với chùm tia siêu âm một gốc từ 75 đến 105 độ |
| Thấy rõ ĐẦU và MÔNG | Thấy rõ hình ảnh cực đầu và cực mông |
| Đặt con trỏ chính xác | Điểm chính giữa của con trỏ nên được đặt ở bờ ngoài của da quanh sọ và bờ ngoài của da mông |
| Phóng đại hình ảnh | Thai nên chiếm ít nhất 2/3 màn hình, thấy rõ Đầu và Mông |
Siêu âm thai được xem là công cụ hỗ trợ đắc lực trong việc xác định tuổi, cân nặng thai nhi
2. Is the ultrasound accurate 4 months pregnant?
Whether the results of pregnancy ultrasound at any time are accurate is something that any pregnant woman wonders about, not just 4 months pregnant. However, at 4 months, after 1⁄3 of development, the fetus needs to be regularly monitored through fetal ultrasound to check and screen for fetal malformations and whether the development is correct or not.4th month of pregnancy also means that the fetus has entered the 14th week of pregnancy, at this stage, the fetal weight can reach about 45g and 10cm long. The limbs of the fetus have clearly developed and divided. The nervous system and muscles also form the fetus can move more flexibly. However, all activities of the baby at this week of pregnancy are still weak, so the mother may not feel it.
When entering the 15th week, the fetus will be about 12cm long and the weight will not have significant growth. The baby's body at 16 weeks will be covered with a thin layer of hair called fluff with varying degrees and many babies are born with hair still attached to them. The epidermis - the surface of the skin is also about to form during this stage. At the same time, the fetal organs continue to develop strongly and the heart has divided into 4 chambers, beating 2 times faster than an adult.
At the 4th month of pregnancy, if the mother performs a regular pregnancy ultrasound, the most accurate results will be obtained.
Thời điểm mang thai tháng thứ 4 nếu mẹ thực hiện siêu âm thai định kỳ sẽ có được kết quả chính xác nhất
3. Determining fetal age and weight through fetal ultrasound
Determining gestational age Determining gestational age through fetal ultrasound images is one of the 3 most popular ways today. Based on the height, weight of the fetus as well as other indicators, the doctor can determine how many weeks the fetus is. From there calculate the expected date of birth of the mother.Although, the time of the first trimester will give the most accurate gestational age results through fetal ultrasound. The results of calculating the due date are usually calculated when the pregnancy is full 12 weeks. However, when the pregnancy reaches 4 months, pregnant women can still ask the doctor to help them determine the gestational age, the error usually ranges from 1 to 7 days.
Determination of fetal weight Today, 2D to 4D fetal ultrasounds can estimate fetal weight at any time of pregnancy using more than 30 continuous algorithms to calculate fetal weight. The fastest and most accurate calculation of the baby's weight.
Determining fetal weight when entering the 4th month is not only a basis to check the development of the fetus, the health of the mother, but also a premise for the delivery process later. However, no matter how modern it is, it is only a prediction and will certainly have errors (falling in the range of 8 -15%).
Determination of fetal weight at 4 months will give more accurate results than in the second half of pregnancy and often depends on a number of related factors such as: fetal position, amniotic volume of how is mom....
Thai phụ 4 tháng nên tắm nắng hàng ngày để giúp bổ sung vitamin D cho cơ thể
4. 4th month pregnancy care
Entering the 4th month, the mother's body will have many changes, it is necessary to note some of the following issues:Prepare more loose and comfortable clothes because the weight may increase and the pregnant belly has grown than. Clean the intimate area daily and change underwear regularly to avoid bladder infections during pregnancy Sunbathing daily to help replenish vitamin D for the body Attend maternity classes to get enough knowledge about pregnancy care The second trimester of pregnancy is a period of strong fetal development. Pregnant women need:
Comprehensive fetal malformation screening by superior 4D ultrasound technique. Screening for gestational diabetes, avoiding many dangerous complications for both mother and baby. Control the mother's weight reasonably to assess the health status of the pregnant woman and the development of the fetus. Understand the signs of threatened early delivery (especially in those carrying multiple pregnancies or having a history of miscarriage or premature birth) so that they can receive timely treatment to maintain pregnancy. To protect mother and baby during pregnancy, Vinmec provides a comprehensive Maternity service to monitor the health status of mother and baby, periodical antenatal check-ups with leading Obstetricians and Gynecologists. enough tests, important screening for pregnant women, counseling and timely intervention when detecting abnormalities in the health of mother and baby.
Please dial HOTLINE for more information or register for an appointment HERE. Download MyVinmec app to make appointments faster and to manage your bookings easily.
