Pregnancy

	SydPath
	Pathology Results in Normal Pregnancy
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Contents

Biochemistry, Endocrinology, Haematology, Iron Studies

Pathology tests may be performed on pregnant women for reasons related to their pregnancy, eg glucose screening for gestational diabetes, or for conditions unrelated to their pregnancy. In the latter circumstance it is important to know if any changes in pathology results are expected changes due to the pregnancy, or may indicate a possible pathological change.

The table below summarises the expected changes during pregnancy for a range of common pathology tests. For more detailed information please contact the laboratory.

TEST	CHANGES IN PREGNANCY
BIOCHEMISTRY
Sodium	Fall to lower end of reference interval.
Potassium	No significant change.
Bicarbonate	Fall to lower end of reference interval.
Urea	Fall to overlapping lower end of reference.
Creatinine	Fall to overlapping lower end of reference interval.
Urate	Rise towards top of reference interval during pregnancy.
Calcium	Fall to lower end of reference interval due to reduction in serum albumin. No change in ionised calcium.
Phosphate	No significant change.
Magnesium	Fall to overlapping lower end of reference interval.
Glucose	Specific testing is recommend at 28 weeks to screen for gestational diabetes.
ALT	No significant change during pregnancy, slight rise post partum.
ALP	Marked increase (up to 4 times normal) in third trimester due to release from placenta.
Amylase	No significant change.
AST	No significant change during pregnancy, slight rise post partum.
CK	No significant change during pregnancy, slight rise post partum.
GGT	No significant change.
Total Protein	Fall to just below reference interval.
Albumin	Fall to just below reference interval, normal 6 weeks post partum.
LDH	Slight increase in last few weeks.
Alpha-1-Antitrypsin	Rise during pregnancy up to twice normal by term.
Caeruloplasmin	Rise during pregnancy up to twice normal by term.
Total Cholesterol	Rise during pregnancy, may reach 9 mmol/L by term.
Triglycerides (fasting)	Rise during pregnancy, may reach 5 mmol/L by term.
ENDOCRINOLOGY
Free Thyroxine	Fall to overlapping lower reference limit in second trimester.
TSH	Slight fall may be seen, especially first trimester.
Cortisol	Marked increase up to 600 - 1500 nmol/L by third trimester

TEST	CHANGES IN PREGNANCY
HAEMATOLOGY
Haemoglobin	Fall to overlapping lower reference limit. Normal by 6 weeks post partum.
MCV, MCH, MCHC	No significant change.
White Cell Count	Rise to overlapping upper reference limit with further increase at delivery.
Platelet count	No significant change.
Prothrombin time	No significant change.
APTT	No significant change.
IRON STUDIES
Iron	No significant change.
Transferrin	Rise to overlapping the upper reference limit.
Transferrin Saturation	Fall to lower end of reference interval during pregnancy.
Ferritin	Fall to lower end of reference interval during pregnancy. Low results may reflect excess iron demands of pregnancy and require treatment.

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For further information please contact Dr Graham Jones on 8382-9100

gjones@stvincents.com.au

Last updated 13/03/2005