OB/GYN Measurements and Dates
Card Set Information
OB/GYN Measurements and Dates
Ultrasound ob gyn
Up to 10 weeks gestational age the mean diameter of the normal gestational sac should grow:
1 mm per day
Physiologic herniation will no longer be present when the crown rump length equals:
Greater than or equal to 45 mm or 4.5 cm
Upper limit of normal diameter measurement of the physiologic midgut herniation is:
Based on the IRP a normal gestational sac should be seen transabdominal at:
Greater than or equal to 3600 mIU/ml
Based on the IRP a normal gestational sac should be seen transvaginal at:
Greater than or equal to 2000mIU/ml
Based on the second international standard, normal gestational sac should be seen transabdominal at:
Greater than or equal to 1800mIU/ml
Based on the second international standard, a normal gestational sac should be seen transvaginal at:
Greater than or equal to 1000 mIU/ml
A yolk sac is considered abnormal when it's diameter exceeds:
Greater than 6 mm
By ____ weeks gestational sac should grow to fill the uterine cavity.
Crown rump length begins to lose accuracy after how many gestational weeks?
Normally, the nuchal translucency does not exceed:
Sonographically, fetal gender cannot be determined until:
16 weeks gestation
A placenta previa can be ruled out if the placental edge is at least ____ from the internal cervical os.
The thickness of a full-term placenta rarely exceeds ____.
As a general rule, one should not see a grade 3 placenta until:
35 to 37 weeks
Epiphyseal centers will not be identified until after:
Nuchal skinfold criteria/measurements are unreliable after ____ weeks.
If no embryo is seen within a sac, one can roughly calculate the gestational age in weeks by measuring the mean sac diameter and adding ___ to it.
Kidneys begin functioning and produce amniotic fluid at ___.
12 to 15 weeks
The postpartum uterus should revert back to the pre-gravid size within:
The postpartum period last:
6 to 8 weeks
Twin growth is similar to that of singletons up to:
_____ is given to Rh negative mothers to protect against alloimmunization, usually at ___ weeks.
RhoGAM; 28 and 32 weeks
A macrosomic fetus is said to weigh ____ at birth.
Normal AFI =
13 cm +/- 10cm
For best results, the optimal gestational age for karyotyping by amniocentesis is:
15 to 16 weeks
At what gestational age is chorionic villus sampling the commonly performed:
10 to 13 weeks
Nuchal fold thickness is usually measured at what gestational age?
15 to 21 weeks
Corpus lutesl cyst usually resolved by:
Pelvic surgery to remove a mass is best performed when?
16 to 20 weeks
Postmenopausal endometrial thickness should measure:
Less than or equal to 5 mm
Normal nulligravid uterus size is:
8 x 3 x 4 cm
Ovulation occurs when the dominant follicle reaches what size?
Periovulatory endometrium is seen on what day of a woman's cycle?
Approximately day 14
Fertilization usually occurs ___ hours after ovulation.
24 to 36 hours
Until ovulation, ovarian follicles grow at a rate of:
2 to 3 mm per day
How soon after conception will pregnancy tests show positive results?
1 to 2 weeks
The second IS for hCG is ____ the IRP level.
When monitoring hormone levels during early pregnancy, normal hCG levels double every ___ hours.
The endometrial canal of a 30-year-old on day eight of her cycle with normal periods should measure:
About 8 mm
With a history of normal menstrual cycles, on which day does ovulation occur?
In absence of fertilization, the corpus luteum cyst should regress after:
The endometrium of a patient receiving hormone replacement therapy would be considered abnormal if it measured more than:
Benign adnexal masses usually measure:
Less than 5 cm
Physicians do not start to consider a C-section due to placental previa until:
At what time is the triple screen performed?
Between 14 and 19 weeks
How much fluid is needed for an amniocentesis?
20 to 30 mL
When is a percutaneous umbilical blood sampling performed?
17 weeks to term
When does the morula reach the endometrial canal?
Day 3 to 4
At which week does the heart tube begin to form and beat?
Which week do fingers and toes form?
What week does the fetus start to swallow amniotic fluid?
What week does the placenta and umbilical cord begin to form?
Stomach should be visualized when the crown rump length equals ___.
23 mm (10 weeks)
Gestational sac at about four weeks is?
Consistent demonstration of the secondary yolk sac is seen when?
5 1/2 weeks
Maximum diameter of the yolk sac is ____ mm when crown rump length equals ___ mm.
6 mm when crown rump length equals 30 to 45 mm
At what week should the yolk sac not be seen?
When is cardiac activity is first seen?
36 days or 6 to 6 1/2 weeks
Cardiac activity is routinely detected when crown rump length equals:
5 to 7 mm
Normal eight weak heart rate
Between 140 and 160 bpm
Bradycardia in the first trimester is considered
Less than 100 BPM before 6.2 weeks or less than 120 BPM between 6.3 and 7 weeks
The most accurate measurement of the gestational age is performed when?
Between 6 and 10 weeks LNMP
A crown rump length of ___ signifies transition from embryo to fetus.
30 to 35 mm
when is the rhombencephalon seen?
From weeks 7 to 9
Midgut herniation should not be present if crown rump length is ___.
greater than or equal to 45 mm
A spontaneous abortion is a pregnancy termination prior to ___ weeks gestation.
A dilated cervix greater than ___ signifies an inevitable abortion.
A yolk sack should be demonstrated when a gestational sac measures ____.
8 mm or greater
An embryo should be demonstrated when gestational sac measurement is ___.
16 mm or greater
The normal range of the cisterna magna measurement is:
3 to 11 mm
AP measurement of renal pelvis should measure ____ prior to 20 weeks.
Less than 4 mm
AP renal pelvis measurement should be ___ after 20 weeks.
less than 7 mm