Today's obstetrician gynecologist is required to interpret and in many cases perform ultrasound scans in the first trimester. In fact, certification of residency programs in many countries requires documentation of adequate exposure to and training in the evaluation of first-trimester ultrasound. Failure to understand the limitations of diagnostic ultrasound or inadequate training of physicians in this technique can result in grave complications for the patient and liability for health-care providers. Identification of missed abortion, ectopic pregnancy, and C-section scar pregnancies. Early identification of multiple gestation and correct determination of chorionicity. The standard of care for performing routine ultrasound examination at 6—7 weeks varies from country to country.
does ultrasound measure gestational age
Ultrasound dating gestational age | sria.info
Obstetric ultrasonography , or prenatal ultrasound , is the use of medical ultrasonography in pregnancy , in which sound waves are used to create real-time visual images of the developing embryo or fetus in the uterus womb. The procedure is a standard part of prenatal care in many countries, as it can provide a variety of information about the health of the mother, the timing and progress of the pregnancy, and the health and development of the embryo or fetus. The International Society of Ultrasound in Obstetrics and Gynecology ISUOG recommends that pregnant women have routine obstetric ultrasounds between 18 weeks' and 22 weeks' gestational age the anatomy scan in order to confirm pregnancy dating, to measure the fetus so that growth abnormalities can be recognized quickly later in pregnancy, and to assess for congenital malformations and multiple pregnancies twins, etc. Performing an ultrasound at this early stage of pregnancy can more accurately confirm the timing of the pregnancy, and can also assess for multiple fetuses and major congenital abnormalities at an earlier stage. There is no difference, however, in perinatal death or poor outcomes for infants. Below are useful terms on ultrasound: .
Predicting date of birth and examining the best time to date a pregnancy
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].
Prenatal testing consists of prenatal screening and prenatal diagnosis , which are aspects of prenatal care that focus on detecting problems with the pregnancy as early as possible. Screening can detect problems such as neural tube defects , chromosome abnormalities, and gene mutations that would lead to genetic disorders and birth defects , such as spina bifida , cleft palate , Downs Syndrome , Tay—Sachs disease , sickle cell anemia , thalassemia , cystic fibrosis , muscular dystrophy , and fragile X syndrome. Some tests are designed to discover problems which primarily affect the health of the mother, such as PAPP-A to detect pre-eclampsia or glucose tolerance tests to diagnose gestational diabetes. Screening can also detect anatomical defects such as hydrocephalus , anencephaly , heart defects , and amniotic band syndrome.