Does Developing Interpregnancy Hypertension Affect the Recurrence Risk of Preeclampsia? A population-based cohort study

BACKGROUND

Preeclampsia in a first pregnancy is a strong risk factor for preeclampsia in a second pregnancy. Whether chronic hypertension developed after a first pregnancy (interpregnancy hypertension) affects the recurrence risk of preeclampsia is unknown.

METHODS

This is a population-based cohort study of 391,645 women with their first and second singleton births between 2006 and 2017. Exposure groups were women with preeclampsia in their first pregnancy, interpregnancy hypertension, or both risk factors. Women with neither risk factor were used as a reference group. We calculated the adjusted relative risk (aRR) with 95% confidence intervals (CIs) for overall preeclampsia in the second pregnancy as well as preterm (<37 gestational weeks) and term (>37 gestational weeks) subgroups of the disease.

RESULTS

Women with preeclampsia in their first pregnancy who did or did not develop interpregnancy hypertension had rates of preeclampsia in their second pregnancy of 21.5% and 13.6%, respectively. In the same population, the corresponding rates of preterm preeclampsia were 5.5% and 2.6%, respectively. After adjusting for maternal factors, women with preeclampsia in their first pregnancy who developed interpregnancy hypertension and those who did not had almost the same risk of overall preeclampsia in their second pregnancy (aRRs with 95% CIs: 14.51; 11.77-17.89 and 12.83; 12.09-13.62, respectively). However, preeclampsia in first pregnancy and interpregnancy hypertension had a synergistic interaction on the outcome preterm preeclampsia (aRR with 95% CI 26.66; 17.44- 40.80).

CONCLUSIONS

Women with previous preeclampsia who developed interpregnancy hypertension had a very high rate of preterm preeclampsia in a second pregnancy, and the two risk factors had a synergistic interaction.

Low-dose aspirin use in pregnancy and the risk of preterm birth: a Swedish register-based cohort study

BACKGROUND

Preterm birth is the leading cause of neonatal mortality and morbidity. Women who have had a previous preterm birth are at increased risk for preterm birth in their subsequent pregnancies. Low-dose aspirin use reduces the risk for preterm birth among women at risk of developing preeclampsia, however, it is unclear whether low-dose aspirin may reduce the risk of recurrent preterm birth.

OBJECTIVE

This study aimed to investigate the association between low-dose aspirin use and preterm birth among women with a previous preterm birth.

STUDY DESIGN

We conducted a Swedish register-based cohort study and included women who had a first and second pregnancy between 2006 and 2019, with the first pregnancy ending in preterm birth (medically indicated or with spontaneous onset <37 weeks of gestation). The association between low-dose aspirin use and preterm birth in the second pregnancy was estimated via logistic regression via standardization and expressed as marginal relative risks with the 95% confidence interval.

RESULTS

Among the study cohort (N=22,127), 3057 women (14%) were prescribed low-dose aspirin during their second pregnancy and 3703 women (17%) gave birth prematurely. Low-dose aspirin use was associated with a reduced risk for preterm birth, (marginal relative risk, 0.87; 95% confidence interval, 0.77-0.99). There were no statistically significant associations between low-dose aspirin use and an altered risk for moderate preterm birth, defined as birth between 32 and 36 weeks' gestation (marginal relative risk, 0.90; 95% confidence interval, 0.78-1.03), or very preterm birth, defined as birth <32 weeks' gestation (marginal relative risk, 0.75; 95% confidence interval, 0.54-1.04). Regarding the onset of preterm birth, low-dose aspirin use was associated with a reduced risk for spontaneous preterm birth (marginal relative risk, 0.70; 95% confidence interval, 0.57-0.86) but no reduction in the risk for medically indicated preterm birth (marginal relative risk, 1.09; 95% confidence interval, 0.91-1.30) was observed.

CONCLUSION

Among women with a previous preterm birth, low-dose aspirin use was associated with a reduced risk for preterm birth. When investigating preterm birth by onset in the second pregnancy, low-dose aspirin use was associated with a reduced risk for spontaneous preterm birth. Our results suggest that low-dose aspirin may be an effective prophylaxis for recurrent preterm birth.

Association Between History of Adverse Pregnancy Outcomes and Coronary Artery Disease Assessed by Coronary Computed Tomography Angiography

IMPORTANCE

Adverse pregnancy outcomes are recognized risk enhancers for cardiovascular disease, but the prevalence of subclinical coronary atherosclerosis after these conditions is unknown.

OBJECTIVE

To assess associations between history of adverse pregnancy outcomes and coronary artery disease assessed by coronary computed tomography angiography screening.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of a population-based cohort of women in Sweden (n = 10 528) with 1 or more deliveries in 1973 or later, ascertained via the Swedish National Medical Birth Register, who subsequently participated in the Swedish Cardiopulmonary Bioimage Study at age 50 to 65 (median, 57.3) years in 2013-2018. Delivery data were prospectively collected.

EXPOSURES

Adverse pregnancy outcomes, including preeclampsia, gestational hypertension, preterm delivery, small-for-gestational-age infant, and gestational diabetes. The reference category included women with no history of these exposures.

MAIN OUTCOMES AND MEASURES

Coronary computed tomography angiography indexes, including any coronary atherosclerosis, significant stenosis, noncalcified plaque, segment involvement score of 4 or greater, and coronary artery calcium score greater than 100.

RESULTS

A median 29.6 (IQR, 25.0-34.9) years after first registered delivery, 18.9% of women had a history of adverse pregnancy outcomes, with specific pregnancy histories ranging from 1.4% (gestational diabetes) to 9.5% (preterm delivery). The prevalence of any coronary atherosclerosis in women with a history of any adverse pregnancy outcome was 32.1% (95% CI, 30.0%-34.2%), which was significantly higher (prevalence difference, 3.8% [95% CI, 1.6%-6.1%]; prevalence ratio, 1.14 [95% CI, 1.06-1.22]) compared with reference women. History of gestational hypertension and preeclampsia were both significantly associated with higher and similar prevalence of all outcome indexes. For preeclampsia, the highest prevalence difference was observed for any coronary atherosclerosis (prevalence difference, 8.0% [95% CI, 3.7%-12.3%]; prevalence ratio, 1.28 [95% CI, 1.14-1.45]), and the highest prevalence ratio was observed for significant stenosis (prevalence difference, 3.1% [95% CI, 1.1%-5.1%]; prevalence ratio, 2.46 [95% CI, 1.65-3.67]). In adjusted models, odds ratios for preeclampsia ranged from 1.31 (95% CI, 1.07-1.61) for any coronary atherosclerosis to 2.21 (95% CI, 1.42-3.44) for significant stenosis. Similar associations were observed for history of preeclampsia or gestational hypertension among women with low predicted cardiovascular risk.

CONCLUSIONS AND RELEVANCE

Among Swedish women undergoing coronary computed tomography angiography screening, there was a statistically significant association between history of adverse pregnancy outcomes and image-identified coronary artery disease, including among women estimated to be at low cardiovascular disease risk. Further research is needed to understand the clinical importance of these associations.

Disruption of the Blood-Brain Barrier by Extracellular Vesicles From Preeclampsia Plasma and Hypoxic Placentae: Attenuation by Magnesium Sulfate

[Figure: see text].

Multi-Fetal Pregnancy, Preeclampsia, and Long-Term Cardiovascular Disease

Supplemental Digital Content is available in the text.

This Swedish register-based cohort study determined the separate and joint contribution of preeclampsia and multi-fetal pregnancy on a woman’s risk of cardiovascular disease (CVD) later in life. The study included 892 425 first deliveries between 1973 and 2010 of women born 1950 until 1971, identified in the Swedish Medical Birth Register. A composite outcome of CVD was retrieved through linkage with the National Patient and Cause of Death Registers. Cox proportional hazard regression was used to assess the risk of CVD in women who had preeclampsia in a singleton or multi-fetal pregnancy, adjusting for potential confounders, and presented as adjusted hazard ratios. Compared with women who had a singleton pregnancy without preeclampsia (the referent group), women with preeclampsia in a singleton pregnancy had an increased risk of CVD (adjusted hazard ratio 1.75 [95% CI, 1.64–1.86]). Women who had a multi-fetal pregnancy without or with preeclampsia did not have an increased risk of future CVD (adjusted hazard ratios 0.94 [95% CI, 0.79–1.10] and 1.25 [95% CI, 0.83–1.86], respectively). As opposed to preeclampsia in a first singleton pregnancy, preeclampsia in a first multi-fetal pregnancy was not associated with increased risk of future CVD. This may support the theory that preeclampsia in multi-fetal pregnancies more often occurs as a result of the larger pregnancy-related burden on the maternal cardiovascular system and excessive placenta-shed inflammatory factors, rather than the woman’s underlying cardiovascular phenotype.

Elevated diastolic blood pressure until mid-gestation is associated with preeclampsia and small-for-gestational-age birth: a population-based register study

BACKGROUND

Gestational hemodynamic adaptations, including lowered blood pressure (BP) until mid-gestation, might benefit placental function. We hypothesized that elevated BP from early to mid-gestation increases risks of preeclampsia and small-for-gestational-age birth (SGA), especially in women who also deliver preterm (< 37 weeks).

METHODS

In 64,490 healthy primiparous women, the change in systolic and diastolic BP from early to mid-gestation was categorized into lowered (≥ 0 mmHg decreased), and elevated (≥ 1 mmHg increase). Women with chronic hypertension, chronic renal disease, pre-gestational diabetes and systemic lupus erythematosus were excluded. Risks of preeclampsia and SGA birth were estimated by logistic regression, presented with adjusted odds ratio (aOR) and 95% confidence intervals (CI). Further, the effect of BP change in combination with stage 1 hypertension (systolic BP 130-139 mmHg or diastolic BP 80-89 mmHg) in early gestation was estimated.

RESULTS

Compared to women with lowered diastolic BP from early to mid-gestation, those with elevated diastolic BP had increased risks of preeclampsia (aOR: 1.8 [1.6-2.0]) and SGA birth (aOR: 1.3 [1.2-1.5]). The risk estimates were higher for preeclampsia and SGA when combined with preterm birth (aORs: 2.2 [1.8-2.8] and 2.3 [1.8-3.0], respectively). The highest rate of preeclampsia (9.9%) was seen in women with stage 1 hypertension in early gestation and a diastolic BP that was elevated until mid-gestation. This was three times the risk, compared to women with normal BP in early gestation and a diastolic BP that was decreased until mid-gestation. The association between elevated systolic BP from early to mid-gestation and preeclampsia was weak, and no significant association was found between changes in systolic BP and SGA births.

CONCLUSION

Elevated diastolic BP from early to mid-gestation was associated with increased risks of preeclampsia and SGA, especially for women also delivering preterm. The results may imply that the diastolic BP starts to increase around mid-gestation in women later developing placental dysfunction disorders.

Cerebral Biomarkers in Women With Preeclampsia Are Still Elevated 1 Year Postpartum

BACKGROUND

There is evidence of cerebral involvement among women with preeclampsia. Levels of the cerebral biomarkers neuron-specific enolase (NSE) and S100B are elevated during pregnancy in women developing preeclampsia. It is although not known if these biomarkers return to normal range postpartum. The aim with this study was to compare levels of S100B and NSE during pregnancy and 1 year postpartum in women who have had preeclampsia to women with normal pregnancies.

METHODS

This study was a longitudinal study of cases (n = 53) with preeclampsia and controls (n = 58) consisted of normal pregnant women in matched gestational weeks. Plasma samples were collected at inclusion during pregnancy and 1 year postpartum. Plasma samples were analyzed for levels of S100B and NSE by enzyme-linked immunosorbent assays kits.

RESULTS

Levels of NSE and S100B in women with preeclampsia were higher during pregnancy than in women with normal pregnancies. One year postpartum, women who have had preeclampsia still had a higher median level of both NSE (5.07 vs. 4.28 µg/l, P < 0.05) and S100B (0.07 vs. 0.06 µg/l, P < 0.05) compared to women with previous normal pregnancies. High levels of NSE and S100B postpartum remained associated with previous preeclampsia after adjustment for confounding factors. Levels of NSE correlated to S100B during pregnancy and postpartum.

CONCLUSIONS

Levels of NSE and S100B are still elevated 1 year postpartum in women who have had preeclampsia in contrast to women with previous normal pregnancies. We hypothesize that there might be a persistent cerebral involvement among women with preeclampsia even 1 year postpartum.

Loss of a close family member the year before or during pregnancy and the risk of placental abruption: a cohort study from Denmark and Sweden

BACKGROUND

Maternal stress during pregnancy is associated with a modestly increased risk of fetal growth restriction and pre-eclampsia. Since placental abruption shares similar pathophysiological mechanisms and risk factors with fetal growth restriction and pre-eclampsia, we hypothesized that maternal stress may be implicated in abruption risk. We investigated the association between maternal bereavement during pregnancy and placental abruption.

METHOD

We studied singleton births in Denmark (1978-2008) and Sweden (1973-2006) (n = 5,103,272). In nationwide registries, we obtained data on death of women's close family members (older children, siblings, parents, and partners), abruption and potential confounders.

RESULTS

A total of 30,312 (6/1000) pregnancies in the cohort were diagnosed with placental abruption. Among normotensive women, death of a child the year before or during pregnancy was associated with a 54% increased odds of abruption [95% confidence interval (CI) 1.30-1.82]; the increased odds were restricted to women who lost a child the year before or during the first trimester in pregnancy. In the group with chronic hypertension, death of a child the year before or in the first trimester of pregnancy was associated with eight-fold increased odds of abruption (odds ratio 8.17, 95% CI 3.17-21.10). Death of other relatives was not associated with abruption risk.

CONCLUSIONS

Loss of a child the year before or in the first trimester of pregnancy was associated with an increased risk of abruption, especially among women with chronic hypertension. Studies are needed to investigate the effect of less severe, but more frequent, sources of stress on placental abruption risk.

Thicknesses of individual layers of artery wall indicate increased cardiovascular risk in severe pre-eclampsia

OBJECTIVE

To assess whether thicknesses of the intima and media in the common carotid artery (CCA) and the intima/media ratio (I/M) indicate an increased cardiovascular risk in non-pregnant women with a history of previous severe pre-eclampsia.

METHODS

Thicknesses of the CCA intima and media layers were measured using non-invasive high-frequency (22 MHz) ultrasound in 42 women with a history of severe pre-eclampsia and 44 women with previous normal pregnancy.

RESULTS

Women with a history of severe pre-eclampsia had a thicker CCA intima and a higher I/M than had women with previous normal pregnancy, also after adjustment for mean arterial pressure, body mass index and CCA intima-media thickness (IMT) (all P < 0.0001). CCA-IMT did not differ significantly between groups. In receiver-operating characteristics curve analysis, intima thickness and I/M clearly discriminated between women with and those without previous pre-eclampsia (area under the receiver-operating characteristics curve (AUC), 0.98 and 0.93), whereas CCA-IMT did not (AUC, 0.52).

CONCLUSIONS

CCA individual intima and media thicknesses as well as I/M, but not CCA-IMT, reflect the known increased long-term cardiovascular risk of pre-eclampsia. Estimation of individual CCA layers using high-frequency ultrasound appears preferable to measuring CCA-IMT for investigating arterial effects and the increased cardiovascular risk in women with a history of severe pre-eclampsia.

Risk of retained placenta in women previously delivered by caesarean section: a population-based cohort study

OBJECTIVE

To evaluate whether women with a caesarean section at their first delivery have an increased risk of retained placenta at their second delivery.

DESIGN

Population-based cohort study.

SETTING

Sweden.

POPULATION

All women with their first and second singleton deliveries in Sweden during the years 1994-2006 (n = 258,608). Women with caesarean section or placental abruption in their second pregnancy were not included in the study population.

METHODS

The risk of retained placenta at second delivery was estimated for women with a first delivery by caesarean section (n = 19,458), using women with a first vaginal delivery as reference (n = 239,150). Risks were calculated as odds ratios by unconditional logistic regression analysis with 95% confidence intervals (95%) after adjustments for maternal, delivery, and infant characteristics.

MAIN OUTCOME MEASURES

Retained placenta with normal (≤1000 ml) and heavy (>1000 ml) bleeding.

RESULTS

The overall rate of retained placenta was 2.07%. In women with a previous caesarean section and in women with previous vaginal delivery, the corresponding rates were 3.44% and 1.96%, respectively. Compared with women with a previous vaginal delivery, women with a previous caesarean section had an increased risk of retained placenta (adjusted OR 1.45; 95% CI 1.32-1.59), and the association was more pronounced for retained placenta with heavy bleeding (adjusted OR 1.61; 95% CI 1.44-1.79).

CONCLUSIONS

Our report shows an increased risk for retained placenta in women previously delivered by caesarean section, a finding that should be considered in discussions of mode of delivery.

Hyperemesis gravidarum and risks of placental dysfunction disorders: a population-based cohort study

Objective

To study whether pregnancies complicated by hyperemesis gravidarum in the first (<12 weeks) or second (12–21 weeks) trimester are associated with placental dysfunction disorders.

Design

Population-based cohort study.

Setting

Sweden.

Population

All pregnancies in the Swedish Medical Birth Register estimated to have started on 1 January 1997 or later and ended in a single birth on 31 December 2009 or earlier (n = 1 156 050).

Methods

Odds ratios with 95% confidence intervals were estimated for placental dysfunction disorders in women with an inpatient diagnosis of hyperemesis gravidarum, using women without inpatient diagnosis of hyperemesis gravidarum as reference. Risks were adjusted for maternal age, parity, body mass index, height, smoking, cohabitation with the infant's father, infant's sex, mother's country of birth, education, presence of hyperthyreosis, pregestational diabetes mellitus, chronic hypertension and year of infant birth.

Main outcome measures

Placental dysfunction disorders, i.e. pre-eclampsia, placental abruption, stillbirth and small for gestational age (SGA).

Results

Women with hyperemesis gravidarum in the first trimester had only a slightly increased risk of pre-eclampsia. Women with hyperemesis gravidarum with first admission in the second trimester had a more than doubled risk of preterm (<37 weeks) pre-eclampsia, a threefold increased risk of placental abruption and a 39% increased risk of an SGA birth (adjusted odds ratios [95% confidence intervals] were: 2.09 [1.38–3.16], 3.07 [1.88–5.00] and 1.39 [1.06–1.83], respectively).

Conclusions

There is an association between hyperemesis gravidarum and placental dysfunction disorders, which is especially strong for women with hyperemesis gravidarum in the second trimester.