Diagnosis of pregnancy

How to diagnose pregnancy in first trimester.

• symptoms
• signs
• investigations

First trimester

Symptoms :

• amenorrhoea
• morning sickness
• increased frequency of micturition
• breast discomfort : feeling of fullness

Signs of pregnancy in first trimester

Breast changes :

in 6—8 wks;

• Enlargement & vascular engorgement;
• Nipple & areola more pigmented;
• Montegomery tubercles become more prominent

Per abdomen - Uterus not felt per abdomen till 12 wks

Pelvic changes

Jacquiemer or chadwick sign : it is the dusky hue of vestibule & anterior vaginal wall visible at about 8th wk

Vaginal sign: sofetning of vaginal walls, there is increased pulsation felt through lateral fornices at 8th wk called osiander sign

Cervix becomes soft with bluish hue as early as 6th wk called goodell sign.

Uterine signs:

• On per vaginal exam
• Size of Hens egg :6th wk
• Cricket ball :8th wk
• fetal head: 12th wk

Hegar sign :

between 6—8 wks

• Upper body of uterus is enlarged by growing fetus and lower part is soft & elastic.
• The cervix is firm
• So on bimannual exam the abdominal and vaginal fingers oppose below the body of uterus ( two fingers in anterior fx and abdominal behind the body of uterus)

HCG

• GLYCOPROTEIN
• Half life is 24 hrs
• Detected in plasma of pregnant women about 7 --9 days after the midcycle surge of LH that precedes ovulation.
• Increase to about 100 iu\ml between 60th-80th days after the last menses
• Beginning at about 10—12 wks the level of HCG in maternal plasma decline, a nadir being reached by about 20 wks.the level then is maintained at this low level for the remainder of pregnancy.

Agglutination inhibition test:

• one drop of urine + one drop of solution that contains hcg antibody.
• If hcg is not present in the urine the antibody remains free.
• Now one drop of another soln that contains latex particles coated c hcg is added
• So the pregnancy test is negative if there is agglutination
• If hcg is present then it would bind the available antibody so there wont be agglutination when the latex coated particles c hcg are added. So no agglutination means pt is pregnant.

Immunological tests

• Agglutination inhibition tests ( urine)

Sn: 0.5—1 iu\ ml

absence of agglutination

positive on 2 days after missed period

• !Direct latex agglutination test urine)

Sn : 0.2 iu\ml

presence of agglutination

positive on 2—3 days after missed period

• Membrane elisa \ card test (urine)

Sn : 30—50 miu\ml

on the first day of missed period

• Elisa test

Sn : 1—2 miu\ml in serum

5 days before the missed period

• ! Radioimmunoassay ( beta subunit) in serum

Sn : 0.002miu\ml

25th day of cycle

Ultrasonography

TVS

• GS & yolk sac 5 menstrual wks

• fetal pole & cardiac activity : 6 wks

• CRL used between 7—12 wks

How to diagnose in second trimester ?

Second trimester

Symptoms :

• amenorrhoea
• quickening : perception of active fetal movements by the mother
• progressive enlargement of lower abdomen

General examination:

Chloasma: pigmentation over forehead and cheek at 24 wk

Breast changes:

More enlarged and prominent veins under skin

Secondary areola usually appear at about 20 wks

Striae visible

Montegomery tubercles are prominent

Abdominal exam:

• linea nigra
• striae

Palpation:

• fundal height
• uterus soft & elastic
• braxton hicks contractions
• palpation of fetal parts by 20th wk
• active fetal movements as early as 20th wk

FHR :

• as early as 20th wk
• uterine suffoule is heard

VE :

bluish discolouration of vulva, vagina & cervix- more evident

Investigations :

USG

How to diagnose in third trimester ?

Third trimester

Symptoms :

• amenorrhoea
• enlargement of abdomen
• lightening at about 38 wks
• frequency of micturition reappears
• fetal movements

Signs :

• Cutaeneous changes more prominent
• Increased pigmentation & striae
• Uterine shape is changed from cylindrical to spherical
• Fundal height
• Braxton hicks contraction more evident
• Fetal movements easily felt
• Fetal parts easily palpable
• FHR

Differential diagnosis of pregnancy

1. Distended urinary bladder
2. Uterine fibroid
3. Cystic ovarian tumour
4. Haematometra (???)
5. Encysted tubercular peritonitis