Circadian blood pressure adaptation and arterial stiffness in pregnancy: An exploratory study

Q: What is the clinical evidence from this study?

Study design: Observational. Population: Healthy pregnancy and reproductive-age normotension (n=81). Intervention: Pregnancy (including gestation ≥20 weeks) vs. Nonpregnant reproductive-age status (and gestation 0.05).

Q: What does this research mean for the field?

Healthy pregnancy is characterized by reduced variability in the Ambulatory Arterial Stiffness Index (AASI) despite comparable mean levels to nonpregnant controls, accompanied by a significant shift to a systolic non-dipper pattern after 20 weeks of gestation. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Cristina López-Sánchez; Jorge L. Hernández; Steffany Castro; Ana Barbosa

doi:10.1038/s41371-026-01251-5

November 7, 2026Journal of Human HypertensionOpen Access

Circadian blood pressure adaptation and arterial stiffness in pregnancy: An exploratory study

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Key result

Healthy pregnancy shows similar arterial stiffness to nonpregnant controls, but induces systolic non-dipping after 20 weeks.

P>0.05
n=81

Why the study?

Data on maternal circadian blood pressure regulation and the Ambulatory Arterial Stiffness Index in Latin American populations remain scarce.

Does healthy pregnancy alter circadian blood pressure patterns and the Ambulatory Arterial Stiffness Index (AASI) on 24-hour ambulatory blood pressure monitoring compared to nonpregnant women of reproductive age?

Key Points

To evaluate circadian blood pressure patterns and the Ambulatory Arterial Stiffness Index in healthy pregnant women compared to nonpregnant controls.
Enrolled 81 women (36 nonpregnant and 45 healthy pregnant; 23 evaluated at <20 weeks and 22 at ≥20 weeks of gestation).
Conducted 24-hour ambulatory blood pressure monitoring to evaluate blood pressure profiles, circadian patterns, and the Ambulatory Arterial Stiffness Index (AASI).
Analyzed differences across pregnancy status and gestational age using Welch tests and bootstrap 95% confidence intervals.
Mean 24-hour blood pressure was 111/66 mmHg in pregnant women versus 115/69 mmHg in nonpregnant women (p > 0.05).
Mean AASI values were 0.33 ± 0.12 in pregnant women compared to 0.31 ± 0.18 in nonpregnant women (p > 0.05), with significantly narrower variability observed during pregnancy.
Systolic dipper patterns shifted significantly after 20 weeks of gestation, with 91% of women at ≥20 weeks exhibiting a non-dipper profile compared to 83% dipper at <20 weeks and 86% dipper in nonpregnant controls (p < 0.00001, Cramer’s V = 0.703).

Study Design

Type

Observational (n=81)

Multicenter

No

Structured PICO

Does healthy pregnancy alter circadian blood pressure patterns and the Ambulatory Arterial Stiffness Index (AASI) on 24-hour ambulatory blood pressure monitoring compared to nonpregnant women of reproductive age?

P

Population

81 healthy Venezuelan women aged 18–45 years (45 pregnant, 36 nonpregnant), free of hypertension, diabetes, or renal disease, evaluated via 24-hour ambulatory blood pressure monitoring.

E

Exposure

24-hour ambulatory blood pressure monitoring (ABPM) with 15-minute daytime intervals and 20-minute sleep intervals during pregnancy (stratified by gestational age <20 weeks vs. ≥20 weeks).

C

Comparator

36 healthy nonpregnant women of reproductive age undergoing identical 24-hour ABPM.

O

Outcome

Ambulatory Arterial Stiffness Index (AASI) and circadian systolic blood pressure patterns (dipper, non-dipper, over-dipper, or riser) over 24 hours.surrogate

Main Result

Absolute Event Rate: 0.33% vs 0.31%

p-value: p=>0.05

Healthy pregnancy in a Venezuelan cohort is characterized by a marked physiological shift toward a nocturnal non-dipper systolic blood pressure pattern after 20 weeks of gestation alongside reduced variability in the Ambulatory Arterial Stiffness Index, establishing preliminary regional reference baselines for maternal vascular adaptation.

Limitations

Modest sample size (exploratory pilot study of 81 women)
Retrospective analysis of a pre-existing database
Cross-sectional evaluation rather than longitudinal follow-up across gestation
Lack of multivariate adjustments for potential confounders such as body mass index and parity
Exclusively normotensive low-risk cohort without high-risk or preeclamptic comparators
Modest sample size (n=81) as an exploratory pilot study
Included only healthy normotensive women, lacking subgroups with chronic hypertension, preeclampsia, or high cardiovascular risk
Lack of multivariate adjustments for confounders such as body mass index, maternal age, parity, prior preeclampsia, and diabetes

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Implication

Healthy pregnancy shifts to systolic non-dipper pattern after 20 weeks with unchanged mean AASI; leaves open whether these patterns predict outcomes in prospective cohorts.

Abstract

Background Maternal vascular adaptation influences blood pressure (BP) regulation and arterial stiffness. Ambulatory blood pressure monitoring (ABPM) allows calculation of the Ambulatory Arterial Stiffness Index (AASI), a non-invasive surrogate of vascular compliance. Data on these parameters in Latin American populations remain scarce. Methods This exploratory study included 81 women (36 nonpregnant; 45 healthy pregnant). 24-hour ABPM assessed BP, circadian patterns, and AASI. Comparisons were made by pregnancy status and gestational age (< 20 vs. ≥20 weeks) using Welch tests and bootstrap confidence intervals. Results Mean 24-hour BP was comparable between pregnant (111/66 mmHg) and nonpregnant women (115/69 mmHg; p > 0.05). AASI values were also similar between groups (0.33 ± 0.12 vs. 0.31 ± 0.18; p > 0.05), though pregnant women exhibited significantly reduced variability confirmed by bootstrap analysis. After 20 weeks, a significant shift from dipper to non-dipper systolic pattern occurred (p < 0.00001, Cramer’s V = 0.703). Circadian patterns and AASI were not significantly associated. Conclusions Pregnancy involves distinct hemodynamic shifts, specifically a non-dipper pattern after mid-gestation and reduced AASI variability. These exploratory findings provide a physiological baseline for vascular adaptation in this population, informing future research on hypertensive disorders.

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Cite This Study

López-Sánchez et al. (2026) conducted an observational in Healthy pregnancy and reproductive-age normotension (n=81). Pregnancy (including gestation ≥20 weeks) vs. Nonpregnant reproductive-age status (and gestation <20 weeks) was evaluated on Ambulatory Arterial Stiffness Index (AASI) (p=>0.05). Healthy pregnancy showed similar mean AASI to nonpregnant controls (0.33 vs 0.31, p>0.05) with reduced variability, and a shift to a systolic non-dipper pattern after 20 weeks (91%, p<0.00001).

synapsesocial.com/papers/6af10ed2a61b6e74a6de156a https://doi.org/10.1038/s41371-026-01251-5

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Circadian blood pressure adaptation and arterial stiffness in pregnancy: An exploratory study

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Circadian blood pressure adaptation and arterial stiffness in pregnancy: An exploratory study

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

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