Table 3.

Coagulation parameters in normal pregnancy (third trimester) and possible alterations in COVID‐19 in association with pregnancy

Laboratory parameter	Normal values				Possible alterations in pregnancy with COVID‐19	Potential prognostic markers	Levels reported in severe COVID‐19 outside pregnancya
	Third trimester of pregnancy			Non‐ pregnant women
PT	8.5–11.0 seconds			16.0 seconds	•COVID coagulopathy Or DIC •PPH	Yes	3 s extension >6 in 47.6% of non‐survivors with DIC compared to 3 in survivors
APTT	25.5–42.5 seconds			27.0–37.0 seconds	•COVID coagulopathy Or DIC •PPH •Consumption events •FVIII release	Yes	5 s extension
D‐dimer	0.16–1.7 μg/mL				•COVID coagulopathy Or DIC •Acute phase reactant •VTE •Trauma •Liver/ renal disease	Yes (severe disease and in hospital mortality Cut off: 2.0 μg/mL)	2.12 in non survivors Vs 0.61 in survivors >3 in 86% non‐survivors with DIC
Platelet count Mean (range)	Third trimester	Delivery	PP		•COVID coagulopathy Or DIC •PPH •Cytokines induced	Yes Thrombocytopenia (severe disease + mortality)	<100 in 33% of non‐survivors <50 in 24% non‐survivors with DIC
	225 (57–505) × 109/L	217 (63–552) × 109/L	264 (91–575) × 109/L	273 (111–999) × 109/L
Fib	2.48–5.06 g/L			2.5–4.0 g/L	•COVID coagulopathy Or DIC •Acute phase reactant •Inflammation •PPH	Yes	5.16 in non survivors vs 4.5 in survivors (non signifcant difference) <1 in 29% non‐survivors with DIC
FDPs	<15 μg/mL			3.09 ± 1.96 μg/mL	•COVID coagulopathy Or DIC •Acute phase reactant		7.6 in non survivors vs 4.0 in survivors

Note

Please note this table is a guide. Age and ethnic variations exist and need to be considered. References:30., 34., 39., 40., 43., 89..

Abbreviations: APTT, activated partial thromboplastin time; DIC, disseminated intravascular coagulopathy; FDPs, fibrin degradation products; Fib, fibrinogen; PP, post partum; PT, prothrombin time; VTE, venous thromboembolism.

^aReference:30; 71% of non‐survivors developed DIC (ISTH DIC score of ≥5) vs 0.6% of survivors.