Dawn Beck, 23 years old
Please sign in or sign up for a March of Dimes account to proceed. Ultrasound dating during pregnancy also called sonogram is a prenatal test offered to most pregnant women. It uses sound waves to show a picture of your baby in the uterus womb. Most women get an ultrasound in their second trimester at 16 to 20 weeks of pregnancy. Some also get a first-trimester ultrasound also called an early ultrasound before 14 weeks of pregnancy. Talk to your provider about when an ultrasound is right for you. The kind you get depends on what your provider is checking for and how far along you are in pregnancy.
Every pregnant woman wants to know her due dateand a due date that is calculated from her last menstrual period with a due date calculator often doesn't match the due date that is estimated by her first ultrasound also known as a sonogram. During an ultrasound, a technician will spread a warm gel over the lower part of your abdomen and then press a tool called a transducer against your belly to examine your fetus ultrasound dating during pregnancy sound waves. An image of your fetus will appear on an accompanying computer screen and while looking at this image, the technician will take some standard measurements from different angles and listen for a heartbeat. Don't worry: This type of exam is painless and risk-free, and seeing your baby for the first time will likely be an enjoyable experience. Naturally, one of the most common questions asked about ultrasound accuracy is: Just how accurate are the due dates that are predicted by an ultrasound? Evidence suggests that, in the first 20 weeks of pregnancythe first ultrasound may be the most accurate tool for predicting when your baby will be born.
Because the human egg is capable of fertilization for only 12 to 24 hours after ovulation the date of ovulation may be taken as being the date of conception. However, ultrasound determination of the date of ovulation has the same imprecision as does the ultrasound estimate of the gestational age and, therefore, a precise date of conception cannot usually be determined as with in vitro fertilization. In addition, although a woman is most likely to become pregnant if she has sex on the day of ovulation conception may also occur from live sperm still in her reproductive tract on the day of ovulation if she had sex for up to five days before ovulation [26,27].
Ultrasound dating during pregnancy
More about ultrasound dating during pregnancy:
A dating scan is an ultrasound examination which is performed in order to establish the gestational age of the pregnancy. Most dating scans are done with a trans-abdominal transducer and a fullish bladder. If the pregnancy is very early the gestation sac and fetus will not be big enough to see, so the transvaginal approach will give better pictures. Dating scans are usually recommended if there is doubt about the validity of the last menstrual period. By 6 to 7 weeks gestation the fetus is clearly seen on trans-vaginal ultrasound and the heart beat can be seen at this early stage 90 to beats per minute under 6 to 7 weeks, then to beats per minute as the baby matures. Ultrasounds performed during the first 12 weeks of pregnancy are generally within 3 - 5 days of accuracy. The most accurate time is between 8 and 11 weeks gestation. This is because the fetus is growing so quickly that there is a big difference in size from week to week. However, the accuracy of the ultrasound examination is always dependent on the skill of the sonographer and ultrasound dating during pregnancy quality of the equipment. The EDD from the early dating scan is used - if the last menstrual period is not known or is unreliable, or the dating scan differs from the last menstrual period dating by more than 5 days.
The results of ultrasound testing provide you and your health care provider with critical information about you and your baby. See below for descriptions of the information gathered from these two types of ultrasounds. Ultrasound uses high-frequency sound waves to create images of the inside of the body. The technique does not use any radiation. It is safe, painless and relatively quick test that usually takes around 30 minutes. The technician will put a warm gel on your abdomen and use a scanning device to get the ultrasound images. Sometimes the ultrasound must be done through the vagina; this procedure may be uncomfortable, but is not considered painful. Ultrasound is not used to diagnose pregnancy, but ultrasound dating during pregnancy used to date a pregnancy and assess numerous health aspects of the fetus and mother. A dating ultrasound gives an accurate estimate of how far along you are in your pregnancy. Many women are uncertain of exactly when conception happened.
Find out what to expect at your first and second trimester ultrasound appointments, what you can learn from those ultrasounds, and why you might need an ultrasound or a few in the third trimester. Relax—You don't have to brace for needles when you get this painless test. During an ultrasound your doctor or a skilled technician uses a plastic transducer to transmit high-frequency sound waves through your uterus. These sound waves send signals back to a machine that converts them into images of your baby. The standard ultrasound arms your doctor with valuable information. It allows him to monitor your baby's growth and track milestones, detect abnormalities, home in on your due date , determine whether you're carrying multiples, see the position of your placenta important for delivery , and a big one for parents-to-be! Another exam that utilizes ultrasound is Doppler fetal monitoring. This test is typically performed during the last trimester on women who suffer from gestational diabetes.