Chapter 50 - OB Measurements and Gestational Age

Question 1

measurement at the level of the stomach, left portal vein, and left umbilical vein

Answer 1

abdominal circumference (AC)

Question 2

fetal parameters of size and proportionality expressed as age

Answer 2

age range analysis (ARA)

Question 3

absence of one (cyclops) or both eyes

Answer 3

anophthalmos

Question 4

average of multiple fetal parameters’ ages

Answer 4

average age (AA)

Question 5

refers to the shape of the cerebellum when a spinal defect is present (cerebellum is pulled downward into the foramen magnum)

Answer 5

“banana” sign

Question 6

measurement that includes both fetal orbits at the same time to predict gestational age

Answer 6

binocular distance (BD)

Question 7

fetal transverse cranial diameter at the level of the thalamus and cavum septum pellucidum

Answer 7

biparietal diameter (BPD)

Question 8

fetal head is relatively wide in the transverse diameter and shortened in the anteroposterior diameter

Answer 8

brachycephaly

Question 9

see gestational sac

Answer 9

chorionic sac

Question 10

most accurate measurement for determining gestational age; made in the first trimester

Answer 10

crown-rump length (CRL)

Question 11

the heart rate before the early 9th week of gestation (after the LMP)

Answer 11

embryonic heart rate (EHR)

Question 12

measurement of the femoral diaphysis

Answer 12

femur length (FL)

Question 13

structure that is normally found within the uterus and contains the developing embryo

Answer 13

gestational sac

Question 14

used in the first trimester to estimate appropriate gestational age with menstrual dates

Answer 14

gestational sac diameter

Question 15

the method whereby the fetus is categorized into small, average, or large growth percentile

Answer 15

growth-adjusted sonar age (GASA)

Question 16

measurement from the humeral head to the distal end of the humerus

Answer 16

humeral length

Question 17

condition in which the orbits are spaced far apart

Answer 17

hypertelorism

Question 18

condition in which the orbits are close together

Answer 18

hypotelorism

Question 19

condition in which the fetus is not growing as fast as normal; usually considered as being malnourished or abnormal

Answer 19

intrauterine growth restriction (IUGR)

Question 20

the first day of the LMP is used as the start date for human pregnancies

Answer 20

last menstrual period (LMP)

Question 21

occurs with spina bifida; frontal bones collapse inward

Answer 21

“lemon” sign

Question 22

small eyes

Answer 22

microphthalmos

Question 23

the condition of having a relatively high cranial vault with a high or peaked appearance; it is caused by molding of the cranium, exaggerating the vertical axis, or in more severe cases by premature closure of the coronal, sagittal, and lambdoidal sutures and with a vertical index above 77

Answer 23

oxycephaly

Question 24

flattening of the vertex of the skull; it is often associated with cranial molding, flattening the top of the skull, and compensatory exaggeration of the biparietal diameter

Answer 24

platycephaly

Question 25

a normal fetus that measures smaller than dates

Answer 25

small for gestational age (SGA)

Question 26

failure of the vertebrae to close

Answer 26

spina bifida

Question 27

fetal head is relatively narrow in the transverse plane and elongated in the anteroposterior plane

Answer 27

dolichocephaly