Viable pregnancy

Viable Pregnancy

 

A)Before scan:

-Calculate gestational age from last menstrual period(LMP).

-Always have ready access to a gestation wheel calculator.

-Gestational age is calculated from the first day of LMP.

Ovulation occur on day 14 from cycle followed by fertilization.

Embryonic age is less than gestational age by 14 days.

 

B)Patient’s Preparation:

-Full bladder(in obese patient use trans-vaginal probe).

C-Doing Examination:

-Identify an intra-uterine fetal sac with a fetal pole and a fetal heart pulsation.

-By trans-vaginal examination

*Fetal sac seen at 4.5 weeks.

*Sac diameter is about 2-4mm.

*Heart pulsation seen at 5 weeks.

*Yolk sac seen at 5 weeks as a 10 mm sac(its predictive value is to confirm intra-uterine pregnancy).

 

-By trans-abdominal route ,  the latter trans-vaginal values are used after adding 1 week.

-Then , Scan the whole uterine cavity from top to bottom and side to side to make sure that you have one sac with smooth outline and to exclude multiple pregnancy

-Then , look to uterine wall to exclude fibroids , uterine abnormalities and also look at the adnexa to exclude ovarian lesions.

 

-Longest image of fetus is taken , freeze and measure the length from end to end ( this is termed crown-rump length ) repeat at least 3 times to be satisfied , then , the machine will convert this to a gestational age.

-Be careful from

*Measuring yolk as the head of fetus.

*Body of the fetus should be fully extended when you take measurement.

 

Checklist

-Calculate gestation from LMP.

-Identify uterus and gestation sac.

-Look for fetal heart pulsation to confirm viability.

-Exclude multiple pregnancy.

-Check adnexa.

-Measure crown-rump length.

-Verify expected delivery date.