Assessing Pregnancy Status & Ultrasound Detection of Heartbeat Flashcards
(16 cards)
what can US detection of baby’s hearbeat confirm?
pregnancy (later on)
what do most common pregnancy tests (panel A) measure concentrations of in urine
- human chorionic gonadotropin (hCG) hormone
what 2 things can hCG be measured in to detect pregnancy
- urine
- blood
what is the chorion
- membrane that develops from trophoblast cells (of outer layer of embryo / blastocyst)
____ layers in early placenta release hCG from ~_ days after conception
- chorion
- ~8 days
why is hCG critical for successful pregnancy
- hCG signals corpus luteum in ovary to stay alive & hence making progesterone (thus endometrium does not shed, ovulation not occur)
from how many days after conception (day 0) can hCG be detected in urine and in blood respectively
~12-14 days in urine
~11 days in blood
when do concentrations of hCG in maternal urine and blood peak during pregnancy
~8-11 weeks into pregnancy
- then decline
what kind of US can detect baby’s heartbeat in a normally-developing pregnancy
transvaginal US
at how many weeks since last menstrual period & how many weeks after conception - can transvaginal US detect baby’s heartbeat
- 6-7 wks from last menstrual period
- 4-5 wks after conception
how many weeks after foetal heart begins to pump blood thru the developing circulation can heartbeat be detected on transvaginal US
1-2wks after
how many days after conception does foetal heart beat rhythmically
~22 days after conception
how many days after conception foes foetal heart begin to pump blood around
~24-25 days after conception
absence of a detectable heartbeat in embryo longer than _mm is diagnostic of pregnancy failure
7mm
how is heart rate (bpm) of foetal heartbeat determined in transvaginal US
- timing of changes in distances between heart tissue layers
list 2 reasons why transabdominal US may not be used to confirm pregnancy
- less sensitive
- may not be able to detect heartbeat until few weeks later in pregnancy
