Chapter 47 The Normal First Trimester Flashcards Preview

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Flashcards in Chapter 47 The Normal First Trimester Deck (31):
1

12 days after conception, during the implantation process

zygote

2

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

embryo

3

After the first 10 weeks

fetus

4

conception as first day of pregnancy

conceptual age or embryologic age

5

First day of last menstrual period as the beginning of gestation

gestational or menstrual age

6

Fertilization occurs withing ______ days after ovulation.

1 to 2 days

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.

23

8

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

4 through week 10

9

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

5.5 to 6 weeks or 35 days

10

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

35mm

11

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

45mm

12

hCG should double every _____ days

2-3 days

13

Gestational sac and hCG peaks at _____ weeks

8-10

14

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

trophoblast, blastocyst

15

Transvaginal transducers are _____ MHz

5 to 8

16

Intrauterine pregnancy usually measures ___ at _____ weeks.

1cm, 5.5 weeks

17

normal sac grows ____ per day in first trimester

1mm

18

Gestational sac has a decidual wall thickness greater than ____.

3mm

19

Endovaginal at _____ weeks gestation and transabdominal at ___ weeks.

4.5, 5

20

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

12mm

21

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

6mm

22

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

5.5, 2-3mm

23

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

chorionic cavity

24

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

8

25

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

8-12, 12

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.

35days, 5 to 5.5 weeks, 8th

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.

90-115, 140-160, 140

28

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

8

29

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

5 to 7

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.

5.5

31

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

12 week