2. Examination in Obstetrics
Introduction:
Fetal ultrasound should be performed only
when there is a valid medical reason.
The lowest possible ultrasonic exposure
settings should be used to gain the necessary
diagnostic information.
3. Classification of Fetal Sonographic
Examinations: (cont.)
Three regimens of routine ultrasound examination are
practiced antenatal:
1. All pregnant women are scanned at or soon after their
booking appointment, i.e., before 15 weeks.
2. Women are scanned at 18-24 weeks gestation for fetal
anatomy survey.
3. In addition to (1) and/or (2), a further optional scan may be
performed in the third trimester as a screening test for
intrauterine growth restriction.
(Only the first scan and scan performed in third trimester
can be performed at the Family Health Centers.)
* Scans at 18-24 weeks gestation for fetal anatomy survey
and other indicated scans have to be referred to a
specialized center.
4. Indications of First-Trimester Ultrasound
(routine) Examination: :
To confirm the presence of an intrauterine pregnancy.
To confirm cardiac activity (fetal viability).
To estimate gestational age.
To diagnose or evaluate multiple gestations.
To evaluate maternal pelvic masses and/or uterine
abnormalities.
To assess for certain fetal anomalies, such as
anenecephaly.
To diagnose hydatidiform mole.
5. If a gestational sac is seen, its location should
be documented.
The gestational sac should be evaluated for
the presence or absence of a yolk sac or
embryo.
The crown-rump length is a more accurate
indicator of gestational (menstrual) age than is
mean gestational sac diameter. However, the
mean gestational sac diameter may be
recorded when an embryo is not identified.
FIRST TRIMESTER
14. c) Fetal number should be reported
Amnionicity and chorionicity should be
documented for all multiple gestations when
possible.
Imaging Parameters for a Standard
Fetal Examination(cont.)
