Beyond monitoring in each trimester, obstetric ultrasound also helps guide invasive procedures such as amniocentesis, in which amniotic fluid is collected with a needle, or to plan delivery in cases of complications.<\/p>\n

First-trimester obstetric ultrasound (Trim I)<\/h2>\n

The first-trimester obstetric ultrasound, or Trim I, is performed between the sixth and 14th weeks of gestation. This initial study is crucial for establishing a solid foundation in prenatal care, and among its main objectives are confirming pregnancy, determining gestational age, evaluating fetal viability by detecting the heartbeat, and observing early development.<\/p>\n

Additionally, it allows the identification of abnormalities that may be severe congenital defects or the development of an ectopic pregnancy.<\/p>\n

Trim I ultrasound also allows nuchal translucency screening, an early indicator of aneuploidies such as Down syndrome.<\/p>\n

Second- and third-trimester obstetric ultrasound (Trim II and III)<\/h2>\n

The second- and third-trimester obstetric ultrasound is essential for evaluating pregnancy progress and ensuring fetal well-being.<\/p>\n

Trim II ultrasound is generally performed between the 18th and 22nd weeks of gestation, and this study is known as the structural or morphological ultrasound because it focuses on a detailed analysis of fetal anatomy.<\/p>\n

Its objectives include the evaluation of fetal anatomy to detect congenital malformations in vital organs such as the brain, heart, and kidneys.<\/p>\n

It also helps determine whether the fetus is growing adequately for gestational age and allows the identification of fetal sex.<\/p>\n

Trim III ultrasound is performed from the 28th week until the end of pregnancy. It helps determine fetal position, such as cephalic presentation (head down) or another position.<\/p>\n

It evaluates the placenta to identify problems such as placenta previa or placental abruption, and it also checks that amniotic fluid levels are normal.<\/p>\n

In addition, it estimates fetal weight, which helps predict possible complications during delivery.<\/p>\n

Trim II and III ultrasounds are crucial for making clinical decisions in the final stages of pregnancy and ensuring a safe birth.<\/p>\n