Related Experiment Videos
Optimal timing of delivery in pregnancies with pre-existing hypertension
J A Hutcheon1, S Lisonkova, L A Magee
1Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC, Canada. jhutcheon@cfri.ca
Objective:
To determine the optimal timing of delivery in pregnancies with pre-existing (chronic) hypertension by quantifying the gestational age-specific risks of stillbirth associated with ongoing pregnancy and the gestational age-specific risks of neonatal mortality or serious neonatal morbidity following the induction of labour.
Design:
Population-based cohort study.
Setting:
USA.
Population:
A total of 171 669 singleton births to women with pre-existing hypertension between 1995 and 2005. Pregnancies additionally complicated by diabetes mellitus, cardiac, pulmonary or renal disease were excluded.
Methods:
The week-specific risks of stillbirth between 36 and 41 completed weeks of gestation were contrasted with the week-specific risks of neonatal mortality or serious neonatal morbidity among births following induction of labour in women with pre-existing hypertension.
Main Outcome Measures:
Stillbirth, neonatal mortality or serious neonatal morbidity (defined as a composite outcome which included any of the following: neonatal seizures, severe respiratory morbidity or 5-minute Apgar score ≤3).
Results:
The risk of stillbirth in women with pre-existing hypertension remained stable at 1.0-1.1 per 1000 ongoing pregnancies until 38 weeks, before rising steadily to 3.5 per 1000 [95% confidence interval (CI): 2.4, 5.0] at 41 weeks. The risk of serious neonatal morbidity/neonatal mortality decreased sharply between 36 and 38 weeks from 137 [95% CI: 127, 146] to 26 [95% CI: 24, 29] per 1000 induced births, before stabilising beyond 39 weeks.
Conclusions:
Among women with otherwise uncomplicated pre-existing hypertension, delivery at 38 or 39 weeks appears to provide the optimal trade-off between the risk of adverse fetal and adverse neonatal outcomes.
Related Concept Videos
Hypertension V: Nursing Management
Hypertension IV: Drug Therapy and Lifestyle Modifications
Hypertension and Regulation of Blood Pressure
Pre-Procedural Guidelines for Assessing Blood Pressure
Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
Special considerations while measuring blood pressure
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.