Chapter 47 - The Normal First Trimester

Question 1

cavity in which the fetus exists; it forms early in gestation and fills with amniotic fluid to protect the fetus

Answer 1

amniotic cavity

Question 2

surrounds the amniotic cavity; the yolk sac is within the chorionic cavity

Answer 2

chorionic cavity

Question 3

invasive diagnostic genetic testing that involves sampling zygotic cells from developing placental tissue

Answer 3

chorionic villi sampling (CVS)

Question 4

most accurate measurement of the embryo in the first trimester

Answer 4

crown-rump length (CRL)

Question 5

the uterine decidual surface on the maternal side of the placenta; the decidual basalis is invaded by trophoblastic cells that form the placenta

Answer 5

decidua basalis

Question 6

the uterine decidua on the surface of the implantation site. As the pregnancy progresses, the decidua capsularis may shed, causing light early pregnancy bleeding

Answer 6

decidua capsularis

Question 7

multiple pregnancy with two amniotic sacs

Answer 7

diamniotic

Question 8

multiple pregnancy with two chorionic sacs

Answer 8

dichorionic

Question 9

interface between the decidua capsularis and the echogenic, highly vascular surface on the opposite side of the endometrial cavity

Answer 9

double decidual sac sign

Question 10

age calculated from when conception occurs

Answer 10

embryologic age (conceptual age)

Question 11

time between 4 and 10 weeks’ gestation

Answer 11

embryonic period

Question 12

production and development of blood cells

Answer 12

hematopoiesis

Question 13

hormone secreted by the trophoblastic cells (developing placental cells) of the blastocyst; laboratory test indicates pregnancy when values are elevated

Answer 13

human chorionic gonadotropin (hCG)

Question 14

intrauterine pregnancy

Answer 14

IUP

Question 15

length of time calculated from the first day of the last normal menstrual period (LMP) to the point at which the pregnancy is being assessed

Answer 15

menstrual age (gestational age)

Question 16

multiple pregnancy with one amniotic sac

Answer 16

monoamniotic

Question 17

multiple pregnancy with one chorionic sac

Answer 17

monochorionic

Question 18

mean sac diameter

Answer 18

MSD

Question 19

first site of formation of red blood cells that will nourish the embryo

Answer 19

primary yolk sac

Question 20

formed at 23 days when the primary yolk sac is pinched off by the extraembryonic coelom

Answer 20

secondary yolk sac

Question 21

high-frequency transducer that is inserted into the vaginal canal to obtain images of first-trimester pregnancy

Answer 21

transvaginal (TV) transducer

Question 22

the umbilical duct connecting the yolk sac with the embryo

Answer 22

yolk stalk

Question 23

the conceptus resulting from the union of male and female gametes. In a normal pregnancy, the zygote travels through the tubes and implants in the uterus

Answer 23

zygote