CODE 1 Eclampsia Eclampsia is characterised by grand mal seizures, hypertension, proteinuria, oedema and may progress to coma. Before a seizure, a patient may experience a body temperature of over 40°C, anxiety, epigastric pain, severe headache and blurred vision. Complications of eclampsia may include cerebral haemorrhage, pulmonary oedema, renal failure, abruptio placentae and temporary blindness (NCCH 2000). CODE 2 Preeclampsia Preeclampsia is a multi-system disorder characterised by hypertension and involvement of one or more other organ systems and/or the fetus. Proteinuria is the most commonly recognised additional feature after hypertension but should not be considered mandatory to make the clinical diagnosis. A diagnosis of preeclampsia can be made when hypertension arises after 20 weeks gestation and is accompanied by one or more of the following: renal involvement, haematological involvement, liver involvement, neurological involvement, pulmonary oedema, fetal growth restriction, placental abruption. Females with Haemolysis, Elevated Liver Enzymes, Low Platelet count (HELLP) syndrome, which is a variant of preeclampsia, are included. CODE 3 Gestational hypertension Gestational hypertension is characterised by the new onset of hypertension after 20 weeks gestation without any maternal or fetal features of preeclampsia, followed by return of blood pressure to normal within 3 months post-partum. In practice, only the first part of this definition—'...the new onset of hypertension after 20 weeks gestation without any maternal or fetal features of preeclampsia...'—can be applied in the perinatal data context, as information is usually collected at birth. CODE 4 Chronic hypertension This may include essential or secondary hypertension. Essential hypertension is defined by a blood pressure greater than or equal to 140 mmHg systolic and/or greater than or equal to 90 mmHg diastolic confirmed before pregnancy or before 20 completed weeks gestation without a known cause. It may also be diagnosed in females presenting early in pregnancy taking antihypertensive medications where no secondary cause for hypertension has been determined. Important secondary causes of chronic hypertension in pregnancy include: - chronic kidney disease, e.g. glomerulonephritis, reflux nephropathy, and adult polycystic kidney disease
- renal artery stenosis
- systemic disease with renal involvement, e.g. diabetes mellitus or systemic lupus erythematosus
- endocrine disorders, e.g. phaeochromocytoma, Cushing's syndrome and primary hyperaldosteronism
- coarctation of the aorta.
Codes 3 and 4 are not to be recorded in conjunction with one another. In the absence of any of the above conditions it is likely that a female with high blood pressure in the first half of pregnancy has essential hypertension. |