Diagnosis of pregnancy in third trimester

Third Trimester -

Last trimester - 29 to 40 week of pregnancy.

Symptoms -
-  Amenorrhoea persists.
-  Enlargement of abdomen is progressive which produce some mechanical
    discomfort to the patient such as palpitation and dyspnea.
-  Lightening at about 38 weeks specially in primigravida.
-  Frequency of micturition reappear.
-  Fetal movements are more pronounced.

Signs -
-  Cutaneous changes are more prominent with increased pigmentation and striae.
-  Uterine shape is changed from cylindrical to spherical behind 36 week.
-  Braxton Hick's contration are more evident.
-  Fetal movements are easily felt.
-  Palpation of fetal parts and there identification much easier.
-  Fetal heart sound heard easily.

Investigation -

Sonography -
Gastational age estimated by sonography and detected by complication.

NST ( Non Stress Test ) - 
The NST monitors the fetal heart rate in response to the fetal well being.

Contration Stress Test ( CST ) / Oxytocin Challanged Test ( OST ) -
It is an invasive method to assess the fetal well being alteration in fetal heart rate
in response to uterine contraction.