Issues in Pregnancy Dating: Revisiting the Evidence

Hunter, Linda

doi:10.1016/j.jmwh.2008.11.003

Cited by 25 publications

(19 citation statements)

References 34 publications

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“…For example, Nadine's induction at 19 weeks and 4 days, and consequent belief that her baby's birth and death could not be registered, caused her severe and continuing distress. Given that the usual methods for calculating gestational age have a margin of error of some weeks (Hunter, 2009), it would have been a simple matter to re-estimate the gestational dates. Alternatively, induction could possibly have been delayed for a few days (compare Debbie's seven-week delay).…”

Section: Journal Of Reproductive and Infant Psychology 71mentioning

confidence: 99%

‘She was a person, she was here’: The experience of late pregnancy loss in Australia

Lee

2012

Journal of Reproductive and Infant Psychology

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Section: Journal Of Reproductive and Infant Psychology 71mentioning

confidence: 99%

‘She was a person, she was here’: The experience of late pregnancy loss in Australia

Lee

2012

Journal of Reproductive and Infant Psychology

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“…These methods may also systematically overestimate or underestimate the GA of the fetuses which are respectively large or small for GA (Sherwood et al, 2000; Lynch and Zhang, 2007). Unsuitable positioning of the fetus during measurement also causes error and the technique is subject to operator error, and the quality of the images (Hunter, 2009; Callen, 2011). For example, 95% confidence intervals of ±4 weeks were found for FL, which is one of the most accurate estimators.…”

Section: Introductionmentioning

confidence: 99%

Assessment of Fetal Development Using Cardiac Valve Intervals

et al. 2017

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An automated method to assess the fetal physiological development is introduced which uses the component intervals between fetal cardiac valve timings and the Q-wave of fetal electrocardiogram (fECG). These intervals were estimated automatically from one-dimensional Doppler Ultrasound and noninvasive fECG. We hypothesize that the fetal growth can be estimated by the cardiac valve intervals. This hypothesis was evaluated by modeling the fetal development using the cardiac intervals and validating against the gold standard gestational age identified by Crown-Rump Length (CRL). Among the intervals, electromechanical delay time, isovolumic contraction time, ventricular filling time and their interactions were selected in a stepwise regression process that used gestational age as the target in a cohort of 57 fetuses. Compared with the gold standard age, the newly proposed regression model resulted in a mean absolute error of 3.8 weeks for all recordings and 2.7 weeks after excluding the low quality recordings. Since Fetal Heart Rate Variability (FHRV) has been proposed in the literature for assessing the fetal development, we compared the performance of gestational age estimation by our new valve-interval based method, vs. FHRV, while assuming the CRL as the gold standard. The valve interval-based method outperformed both the model based on FHRV. Results of evaluation for 30 abnormal cases showed that the new method is less affected by arrhythmias such as tachycardia and bradycardia compared to FHRV, however certain types of heart anomalies cause large errors (more than 10 weeks) with respect to the CRL-based gold standard age. Therefore, discrepancies between the regression based estimation and CRL age estimation could indicate the abnormalities. The cardiac valve intervals have been known to reflect the autonomic function. Therefore the new method potentially provides a novel approach for assessing the development of fetal autonomic nervous system, which may be growth curve independent.

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“…Once released, eggs stay alive for 12-24 hours unless fertilised. A fertilised egg takes about a week to travel through a fallopian tube and implant in the placenta, but ovum travel speed varies from woman to woman (Hunter, 2009). Regardless, most gestational age formulas Global Public Health 9 calculate using day 14 of a 28-day cycle as the conception date, with pregnancies lasting 280 days from the first day of the last menstrual period (LMP).…”

Section: Gestational Agementioning

confidence: 99%

Global health indicators and maternal health futures: The case of Intrauterine Growth Restriction

Erikson

2015

Global Public Health

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Public health indicators generally operate in the world as credible, apolitical and authoritative. But indicators are less stable than they appear. Clinical critiques of Intrauterine Growth Restriction (IUGR) criteria have been forthcoming for decades. This article, though, takes up the measuring and calculation gradients of IUGR in the ultrasound machine itself, including the software algorithms that identify IUGR. One hospital where research was conducted incorrectly predicted pathological birth outcomes 14 of 14 times. We are at a historical moment when the global use of prenatal diagnostic ultrasound for the express purpose of assessing IUGR is set to escalate. Medical imaging device corporations like Siemens, Toshiba, General Electric and Phillips are quite literally banking on it, and new forms of ultrasound technology and diagnostic software are increasingly available on smartphones, tablets and laptops. Clinical guidelines for IUGR--assumed to be authoritative and evidence-based--are evolving right along with the installation throughout the world of the technology capable of diagnosing it. Maternal malnutrition remains the single strongest predictive factor for IUGR, regardless of the technological investments currently amassing to identify the indicator, which is cause for a reassessment of priority spending and investment.

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Issues in Pregnancy Dating: Revisiting the Evidence

Cited by 25 publications

References 34 publications

‘She was a person, she was here’: The experience of late pregnancy loss in Australia

‘She was a person, she was here’: The experience of late pregnancy loss in Australia

Assessment of Fetal Development Using Cardiac Valve Intervals

Global health indicators and maternal health futures: The case of Intrauterine Growth Restriction

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