Hypertensive diseases of pregnancy and parity.

Chesley's classic long-term follow up study of eclamptic women clearly demonstrated the prognostic significance of parity in the differential diagnosis of various hypertensive diseases of pregnancy. Multiparous patients with eclampsia were different on long-term follow-up from primiparous eclamptic women. A logical conclusion from this observation is that multiparous and primiparous patient groups should be analyzed separately whenever hypertensive diseases of pregnancy are evaluated. This study is therefore an attempt to define the clinical profile of hypertension during pregnancy on the basis of parity alone. The prenatal and hospital records of 99 successive pregnant patients identified as hypertensive during a 1-year period at Mount Sinai Hospital Medical Center served as the study population. A group of 25 primiparous and 25 multiparous patients, all with uncomplicated pregnancies and normal deliveries in sequence during a 1-month period, served as normal nonhypertensive control groups. Various pregnancy parameters were statistically evaluated for study and control groups. Significant differences were found between hypertensive primiparous and multiparous patients in mean weight increase (p less than 0.05), gestational age at first increase in blood pressure (p less than 0.007), and time from first increase in blood pressure until delivery (p less than 0.008). The difference in birth weight was not significant between hypertensive groups. In contrast, among the control groups, multiparous patients had significantly larger offspring than primiparous patients (p less than 0.01). Weights of normal primiparous control women were almost identical to those of primiparous hypertensive women (3252.8 +/- 511.8 versus 3203.26 +/- 679.5 gm). Birth weights of offspring from multiparous hypertensive women, while not significantly different from those of primiparous hypertensive women, were significantly lower than those of multiparous control subjects (3093.94 +/- 898.7 versus 3593 +/- 305.6; p less than 0.01). No significant differences in a variety of laboratory findings, reflexes, edema, or mode of delivery were observed between the various groups. The clinical and laboratory presentation of hypertension in pregnancy may be similar between primiparous and multiparous patients. Nevertheless, clear differences do exist in both maternal presentation and impact of maternal disease on fetal growth and development. These differences strongly suggest a different pathophysiology as the underlying cause of hypertensive disease in primiparous and multiparous pregnant women.(ABSTRACT TRUNCATED AT 400 WORDS)