Page 101 - كتاب تمريض نسا الاكتروني

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(III) Special investigations

1. Pregnancy tests: detect human chorionic gonadotrophic in maternal urine or

serum

Urine test:

Sensitive urine pregnancy test including home kits are now available. An example is the

ELISA tests (enzyme-linked immunosorbent assay tests) which detect 10-20 m IU\ml of

HCG and can diagnosis pregnancy at the time of missed period in 95% of cases. The

sensitivity of home tests ranges from 10 to 50 m IU\ml.

Blood test:

Detection of beta-subunit of HCG in serum by radioimmunoassay is a very sensitive test

and detects small amounts of the hormone (one mI U\ml of beta-subunit and even

lower). It can diagnose pregnancy before the first missed period by 5-7 days (becomes

positive one day after implantation).

2. Sonography: done for:

1. detect intrauterine pregnancy

2. confirm fetal cardiac activity

3. diagnose multiple pregnancy

It means the use of sound waves above the range of human hearing hence the term

ultrasonic technique. By transvaginal sonography, the pregnancy sac appears as a white

ring at 4 weeks of pregnancy, the fetal pole at 5 weeks, and fetal heart movement at 6

weeks. Transabdominal ultrasound is less sensitive with about one week difference. Also

the fetal heart sounds can be heard after the 10 week by Doppler stethoscope (Doptone
th
or Sonicaid).

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