Am Fam Physician. 2003;68(11):2270-2272
Although almost 30 percent of first pregnancies are believed to be complicated by hypertension, preeclampsia, or eclampsia, the long-term implications for these mothers are unclear. These hypertensive conditions of pregnancy have been reported to be associated with hypertension later in life, but small size and other limitations of the studies limit the ability of physicians to use these results to counsel patients or identify women at increased risk of significant hypertension. Wilson and colleagues used data about women who delivered in a Scottish city between 1951 and 1970 to clarify the risk of developing hypertension years after having a hypertensive condition of pregnancy.
From the original cohort of 3,593 women, they identified 1,197 who had gestational hypertension and 1,199 who had preeclampsia/eclampsia during their first singleton pregnancy. To provide a control group, these women were matched by age and year of delivery with 1,197 mothers who had no elevations of blood pressure during pregnancy. Women with chronic hypertension at the time of pregnancy were excluded from the study. Community health registers were used to identify all participants still living in the United Kingdom. National data registries provided information about women who had died. Women still living in the region were invited to complete a health questionnaire and undergo medical examination.
Overall, the average age at delivery was 24 years. Women in the control group were more likely to be of higher social status than those in the hypertensive groups. Questionnaires were returned from 1,312 women, and 992 presented for medical examination. Women who had hypertension or preeclampsia/eclampsia were significantly more likely than control subjects to have evidence of later hypertension, even after adjustment for risk factors for hypertension. The odds ratio for a physician-confirmed diagnosis of hypertension was 2.67 in women who had gestational hypertension and 3.02 in women with preeclampsia/eclampsia (see accompanying table). Similarly, the odds ratios for taking antihypertensive medication were 2.01 and 2.14, respectively.
Women who had hypertensive conditions of pregnancy also had higher odds ratios for many of the serious adverse outcomes of hypertension later in life. For stroke, gestational hypertension had an odds ratio of 2.23, and preeclampsia/eclampsia had an odds ratio of 3.39; for angina, odds ratios were 1.11 and 1.59, respectively; and for intermittent claudication, 1.56 for both pregnancy conditions. Women in the two groups were more likely to have been admitted to a hospital for circulatory diseases, especially hypertension. Analysis of the 265 deaths identified in the study population revealed that total mortality, stroke, and cardiovascular mortality were higher in the gestational hypertension and preeclampsia/eclampsia women than in the control group, and significantly higher for stroke in women who had preeclampsia/eclampsia.
The authors conclude that hypertensive conditions of pregnancy are associated with hypertension later in life and that women with this history have an increased risk of stroke and cardiovascular disease. The magnitude of the risk appears to be at least double that of women who do not have hypertension during pregnancy, but the risk is even more increased in those who have preeclampsia.
| Gestational hypertension | Preeclampsia/eclampsia | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Outcome | Control* | No.* | Odds ratio (unadjusted) | Adjusted odds ratio† (95% CI) | P value | No.* | Odds ratio (unadjusted) | Adjusted odds ratio † (95% CI) | P value |
| Hypertension, physician diagnosis | 76/277 | 215/428 | 2.67 | 2.47 (1.74 to 3.51) | <.001 | 327/542 | 3.02 | 3.98 (2.82 to 5.61) | <.001 |
| Currently taking antihypertensive medication | 43/295 | 113/442 | 2.01 | 1.89 (1.23 to 2.88) | .003 | 151/565 | 2.14 | 1.90 (1.27 to 2.86) | .002 |
| Stroke, physician diagnosis | 3/266 | 10/404 | 2.23 | 2.42 (0.59 to 9.98) | .22 | 19/511 | 3.39 | 3.41 (0.95 to 12.2) | .06 |
| Angina, physician diagnosis | 24/273 | 40/413 | 1.11 | 1.02 (0.58 to 1.81) | .94 | 69/518 | 1.59 | 1.61 (0.95 to 2.73) | .08 |
| Angina, Rose criteria | 22/290 | 34/441 | 1.02 | 0.93 (0.52 to 1.65) | .80 | 47/559 | 1.12 | 0.90 (0.52 to 1.55) | .69 |
| Possible MI, physician diagnosis | 14/268 | 16/408 | 0.74 | 0.73 (0.32 to 1.63) | .44 | 20/512 | 0.74 | 0.76 (0.35 to 1.63) | .48 |
| Possible MI, Rose questionnaire | 22/292 | 19/444 | 0.55 | 0.48 (0.25 to 0.95) | .03 | 36/569 | 0.83 | 0.84 (0.47 to 1.50) | .56 |
| Intermittent claudication, Rose criteria | 3/292 | 7/440 | 1.56 | 1.54 (0.38 to 6.19) | .55 | 9/565 | 1.56 | 1.57 (0.41 to 6.05) | .51 |
| DVT, physician diagnosis | 22/269 | 25/404 | 0.74 | 0.65 (0.35 to 1.20) | .17 | 33/510 | 0.78 | 0.75 (0.42 to 1.34) | .32 |
| Kidney disease, physician diagnosis | 7/267 | 9/398 | 0.85 | 0.64 (0.22 to 1.82) | .40 | 28/508 | 2.17 | 2.39 (1.01 to 5.65) | .05 |
editor's note: Data increasingly indicate that preeclampsia is an arterial, possibly even an endothelial, disease. While the molecular level research can be difficult to understand, it is clear that we are close to a real understanding of the mechanisms of these conditions. We hope that more effective treatments will follow. As family physicians, we appreciate the full implications of preeclampsia as one manifestation of a complex, familial arterial disease. The overt message of this study is to be especially vigilant for cardiovascular disease in women who have any history of hypertension during pregnancy. Perhaps we can go further. Can we use family history to identify the young woman who is at risk of hypertension even before she becomes pregnant, and assist her to avoid not just a difficult pregnancy, but possibly a premature cardiovascular disease?—a.d.w.