Chapter 47 The Normal First Trimester

Question 1

12 days after conception, during the implantation process

Answer 1

zygote

Question 2

From the time of implantation until the end of the 10th week menstrual age

Answer 2

embryo

Question 3

After the first 10 weeks

Answer 3

fetus

Question 4

conception as first day of pregnancy

Answer 4

conceptual age or embryologic age

Question 5

First day of last menstrual period as the beginning of gestation

Answer 5

gestational or menstrual age

Question 6

Fertilization occurs withing ______ days after ovulation.

Answer 6

1 to 2 days

Question 7

At approximately _____ days menstrual age, the primary yolk sac is pinched off by the extraembryonic coelom, forming the secondary yolk sac. The amniotic chorionic cavities also develop and evolve during this period of gestation.

Answer 7

23

Question 8

The embryonic phase occurs from week ______. During this phase all major internal and external structures begin to develop.

Answer 8

4 through week 10

Question 9

The cardiovascular system undergoes rapid development, with the initial heartbeat occurring at between _______ weeks or ____ days.

Answer 9

5.5 to 6 weeks or 35 days

Question 10

The crown-rump length measures _____ by the end of the 10th week.

Answer 10

35mm

Question 11

The gestational sac is approximately ____ mean sac diameter at ten weeks.

Answer 11

45mm

Question 12

hCG should double every _____ days

Answer 12

2-3 days

Question 13

Gestational sac and hCG peaks at _____ weeks

Answer 13

8-10

Question 14

1st trimester hCG is secreated by the _________ cells of the ________.

Answer 14

trophoblast, blastocyst

Question 15

Transvaginal transducers are _____ MHz

Answer 15

5 to 8

Question 16

Intrauterine pregnancy usually measures ___ at _____ weeks.

Answer 16

1cm, 5.5 weeks

Question 17

normal sac grows ____ per day in first trimester

Answer 17

1mm

Question 18

Gestational sac has a decidual wall thickness greater than ____.

Answer 18

3mm

Question 19

Endovaginal at _____ weeks gestation and transabdominal at ___ weeks.

Answer 19

4.5, 5

Question 20

failure to visualize the yolk sac, with a minimum of _____ MSD, using transvaginal sonography, should provoke suspicions of abnormal pregnancy.

Answer 20

12mm

Question 21

The normal diameter of the yolk sac should not exceed ____.

Answer 21

6mm

Question 22

The early embryo is often not identified until hear motion is detected at approximately ______, when the CRL is _____.

Answer 22

5.5, 2-3mm

Question 23

The anechoic center of 5-6 week gestational sac represents the _______.

Answer 23

chorionic cavity

Question 24

by week ____, three primary vesicles are seen within the feta brain: the prosencephalon, mesencephalon, and rhombencephalon.

Answer 24

8

Question 25

The mid-gut herniation occurs and is normally seen between _____ weeks. Normally returns into the abdomen by ___ weeks.

Answer 25

8-12, 12

Question 26

The embryonic heart starts beating at approximately ___ days (______ weeks). By the end of the ____ week of gestation, the has has reached its adult configuration.

Answer 26

35days, 5 to 5.5 weeks, 8th

Question 27

Rates of ____ to ____ beats per minute at 6 weeks increases to rates of ____ to ____ beats at 9 weeks, with rates of approxmatly ____ beats the remainder of the the late first and second trimester.

Answer 27

90-115, 140-160, 140

Question 28

As a rule, the gestational sac size remains accurate through the first ____ weeks of gestation.

Answer 28

8

Question 29

Crown-Rump length is most accurate dating parameters for gestation dating. Deviations of plus or minus _____ days.

Answer 29

5 to 7

Question 30

CRL measurements can be obtained as early as ____ weeks using transvaginal scanning. visualization of heart motion is a marker signifying the beginning of CRL measurements.

Answer 30

5.5

Question 31

CRLs are considered the most accurate method for dating through ______ gestation.

Answer 31

12 week