Oxford Handbook of Midwifery (97 page)

Test

Non-pregnant

Pregnancy

PIH/PET

DIC

Notes

Causes of abnormal result

Bilirubin (mmol/L
^–1
)

2–17

2–17

May (i)

–

Product of red cell breakdown.

PIH/HELLP

Lactic dehydrogenase (LDH) (U/L
^–1
)

100–300

100–300

May (i)

–

Levels may (i) in last few weeks of pregnancy. Significant increases

Significant increases in PIH

in PIH/HELLP.

ALP (U/L
^–1
)

40–125

(i) 2–4 times

–

–

Normal increase (2–4 times)

due to placental production

Calcium (mmol/L
^–1
)

2.12–2.62

2.12–2.62

–

–

Fall to lower end of reference

interval due to reduction

in serum albumin. No change

in ionized calcium

Bile acids (μmol/L
^–1
)

0–6

0–14

–

–

Measured in pruritus

(i to i i) in cholestasis

of pregnancy

Test

Non-pregnant

Pregnancy

PIH/PET

DIC

Notes

Causes of abnormal result

Blood gas results

P
_a
O
₂
(kPa)

13 (12–15)

13.7

May (d)

–

May be lower in the supine position

Fall in PIH/HELLP due to fluid overload. Blood gas