First trimester ultrasounds are typically performed between 5 and 10 weeks gestational age to evaluate the number of fetuses, determine the location of the pregnancy, detect fetal heart rate, assess viability, determine estimated due date, and evaluate the maternal uterus and ovaries. The scan is typically performed with a transvaginal transducer.
Indications for the exam may include uncertain last menstrual period or irregular cycles, pelvic pain, history of miscarriage or tubal pregnancy, vaginal bleeding, or multiple gestation pregnancy.
Nuchal Translucency (NT) Screening
Nuchal translucency screenings can reliably assess a mother's risk for having a baby with Down Syndrome, Trisomy 18 and 13 in the first trimester of pregnancy between 11 and 13 weeks. The ultrasound exam is used to confirm the gestational age of the fetus and measures the nuchal translucency (NT), which is a layer of fluid behind the fetus' neck, and determines the presence or absence of a fetal nasal bone (NB).
The NT screening has two steps:
An ultrasound exam to measure the size of the clear space in the tissue at the back of the baby's neck (nuchal translucency)
A maternal blood sample is collected by a simple finger stick and then sent to a laboratory for analysis of three biochemical markers: pregnancy associated plasma protein-A (PAPP-A.), alpha fetoprotein (AFP), and free beta human chorionic gonadotropin (free beta hCG)
These combined biophysical and biochemical markers produce a detection rate of 96% with a false positive rate of just 2%. American College of Obstetrics and Gynecology ACOG recommends that all pregnant women, regardless of their age, should be offered screening or diagnostic testing for genetic disorders.
The anatomic survey ultrasound, which is a detailed evaluation of your baby’s development is typically performed between 18 and 22 weeks gestational age. Measurements of the baby's head, abdomen, femur and humerus will be obtained and used to determine the baby’s size and rate of growth. The brain, heart, spine, stomach, bowel, abdominal wall, kidneys, bladder, face and limbs are thoroughly evaluated to identify abnormalities. The umbilical cord, amniotic fluid volume, and cervical length are also assessed along with the placenta location and development. Gender can also be determined at this time if desired.
Biophysical Profile (BPP)
The Biophysical Profile or fetal well-being sonogram is used to provide an overall measure of your baby’s wellbeing. A Biophysical Profile (BPP) may be requested by your healthcare provider to address concerns that arise during the course of your pregnancy, or if you have experienced complications with a previous pregnancy.
During the BPP we will assess the baby’s position and activity, evaluate amount of amniotic fluid, evaluate the position and structure of the placenta, assess blood flow to the baby and placenta and measure the baby’s size and determine growth rate.