Late 1st Trimester

Late 1st trimester

• Transabdominal approach. If limited visualization, proceed to transvaginal approach.

• Obtain uterine measurements in sagittal and transverse planes transabdominally.

o Uterine length and height taken in sagittal plane, width taken in transverse plane.

• Note uterine contour and measure and document location any fibroids and describe in report.

• Identify and measure the cervix.

• Note the presence of absence of free fluid in the cul-de-sac.

• Image bilateral adnexa.

• Identify and measure each ovary length, height and width.

o Document and measure any cysts and/or masses present. Note appearance of cyst/mass on report.

• Identify intrauterine gestational sac and note location in the uterus.

• Identify the fetus and number present.

• Identify placental location and placental cord insertion with color flow Doppler. With multiples, establish chorionicity.

• Obtain CRL measurements x3 (minimum) in longest plane of fetus.

• Document FHR using M-mode Doppler only. A minimum of 3-5 cycles should be obtained. Do not use color flow Doppler on fetus unless confirming demise.

• Image early anatomy

o Cranium at level of BPD is seen closed with “butterfly” sign seen.

o Upper Extremities.

o Fetal heart, as close to a 4-chamber heart view as possible.

o Document situs

o Abdomen with intact anterior wall and present/absent stomach bubble at level of AC

o Cord insertion into abdomen.

o Bladder

o Lower Extremities.

o Nuchal Translucency measurement following below criteria.

o 3-D image

• Nuchal Translucency image requirements:

• Gestational age between 11 weeks 1 day and 13 weeks 6 days.

• Clear borders of NT.

• Fetus in mid-sagittal plane: 3rd and 4th ventricles seen in CNS with tip of fetal nose seen in profile. No ribs, spine, stomach or heart seen in image.

• Fetus occupies majority of image. (>50%)

• Neutral fetal head position.

• Fetus observed away from amnion.

• (+) calipers used.

• Calipers placed perpendicular to long axis of fetus.

• Measured at widest NT space.

• Calipers placed just inside the borders of the NT with none of the crossbar present inside NT space.

 If NT measurement is 3.0mm or greater, patient must be scheduled for GC. Also, a Level 3, FE should be scheduled at the appropriate gestational age.

• NOTE- Sequential Screening: if patient elects testing, CRL must measure between 45- 84 mm and a minimum of 3 NT measurements (meeting above criteria) must be obtained, using the largest of the best images for testing. Note NT measurement in report.

• Offer genetic testing and have patient sign consent/declination form.

• If patient desires cell free DNA testing patient must be scheduled with GC.

• Complete ultrasound report, including any abnormal findings.

• Schedule follow up for screening patients.