Intrauterine programming of the cardiovascular system

Impact of prospective measurement of outflow tracts in prediction of coarctation of the aorta

OBJECTIVES

Prenatal diagnosis of coarctation of the aorta (CoA) is associated with reduced mortality and morbidity, however, accurate prenatal prediction remains challenging. To date, studies have used retrospective measurements of the outflow tracts to evaluate their potential to predict CoA. Our primary objective was to evaluate prospectively acquired measurements of the outflow tracts in fetuses with prenatally suspected CoA. A secondary aim was to report the postnatal prevalence of bicuspid aortic valve in this cohort.

METHODS

Pregnancies with suspicion of isolated CoA and with a minimum of 6 months' postnatal follow-up available were identified from the cardiac database of a tertiary fetal cardiology center in the UK, between January 2002 and December 2017. Measurement of the aortic valve, pulmonary valve, distal transverse aortic arch (DTAA) and arterial duct (AD) diameters were undertaken routinely in fetuses with suspected CoA during the study period. Z-scores were computed using published reference ranges based on > 7000 fetuses from our own unit.

RESULTS

Of 149 pregnancies with prenatally suspected CoA included in the study, CoA was confirmed within 6 months after birth in 77/149 (51.7%) cases. DTAA diameter Z-score and the Z-score of second-trimester DTAA/AD diameter ratio were smaller in fetuses with postnatally confirmed CoA than those in false-positive cases (-2.8 vs -1.9; P = 0.039 and -3.13 vs -2.61; P = 0.005, respectively). Multiple regression analysis demonstrated that the Z-scores of DTAA and AD diameters were the only significant predictors of postnatal CoA (P = 0.001). Bicuspid aortic valve was identified in 30% of the false-positive cases.

CONCLUSIONS

Measurement of DTAA and AD diameter Z-scores can be used to ascertain risk for postnatal CoA in a selected cohort. The high incidence of bicuspid aortic valve in false-positive cases merits further study with respect to both etiology and longer-term significance. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Smoke Exposure and Kidney Outcomes in School-Aged Children

BACKGROUND

Fetal smoke exposure may result in developmental adaptations that permanently affect the developing kidney. In this study, the associations of maternal and paternal smoking during pregnancy with childhood kidney size and function were assessed.

STUDY DESIGN

Prospective cohort study from fetal life onward.

SETTING & PARTICIPANTS

This study was conducted in a group of 5,622 children in Rotterdam, the Netherlands.

PREDICTORS

Maternal and paternal smoking were assessed during pregnancy by questionnaires.

OUTCOMES & MEASUREMENTS

At a median age of 6.0 (5th-95th percentile, 5.6-7.9) years, we measured childhood kidney volumes, estimated glomerular filtration rate (eGFR), and albumin-creatinine ratio.

RESULTS

The confounder model, which included size at birth, shows that compared with children from mothers who did not smoke during pregnancy, those from mothers who continued smoking during pregnancy had smaller combined kidney volumes at the age of 6 years. The strongest effect estimate was observed for mothers who smoked 5 or more cigarettes per day during pregnancy (difference for combined kidney volume, -2.80 [95% CI, -5.15 to -0.45] cm(3)). Similarly, continued maternal smoking during pregnancy also was associated with a lower eGFR in childhood (difference, -2.25 [95% CI, -3.70 to -0.79] mL/min/1.73 m(2)). First-trimester-only smoking was associated with a higher risk of increased albumin-creatinine ratio (OR, 1.45; 95% CI, 1.05-2.01). Among mothers who did not smoke during pregnancy, paternal smoking was associated with smaller childhood combined kidney volume (difference, -1.78 [95% CI, -3.48 to -0.07] cm(3)), but not with childhood kidney function measures.

LIMITATIONS

Smoking behavior was measured with questionnaires. Follow-up measurements were available for only 70% of the children.

CONCLUSIONS

Continued maternal smoking during pregnancy is associated with smaller combined kidney volume and lower eGFR in school-aged children. Stronger effect estimates for maternal versus paternal smoking suggest that intrauterine adaptive responses may play a role as underlying mechanisms.

Parachuting and pregnancy: what do we know about pregnant skydivers and the risks they are taking?

OBJECTIVE

There is little medical knowledge about the risks of skydiving during pregnancy. Some national parachuting associations ask for a doctor's permission; others recommend not jumping at all during pregnancy. This article provides survey data and a literature review of pregnancy and parachuting/skydiving related issues to help the pregnant skydiver and her obstetrician make an informed decision. Survey data presented include pregnancy, delivery, and parachuting information from skydivers who jumped during pregnancy.

DESIGN

International retrospective anonymous online questionnaire considering the Checklist for Reporting Results of Internet E-Surveys (CHERRIE). The PubMed database was searched with using the terms "skydive," "pregnancy," and "parachute" (query April 2013).

SETTING

Web page questionnaire on skydivers' epidemiology, experience, and pregnancy-related information.

PARTICIPANTS

Fifty-seven parous female skydivers.

ASSESSMENT OF RISK FACTORS

Information on athletes' experience, weather conditions, obstetric history (gravida, gestational week), delivery mode was obtained.

MAIN OUTCOME MEASURES

Epidemiology of pregnant skydivers and literature review to provide information on skydiving risks.

RESULTS

Women do actively decide to skydive while pregnant. The majority of our participants were between 25-year-old and 35-year-old primips with 100 to 1000 jumps experience, answering the questionnaire from a European IP address. Precautions are taken in terms of weather conditions, gear, or sports partner. The literature review found no relevant literature regarding the question. Literature is searched for risk factors that come close to the ones in skydiving (ie, oxygen saturation, shock forces, and others). Further studies are needed to show the long-term effect of stress or low O2 saturation on antenatal programming, or short-term hypoxia and pregnancy outcome in pregnant skydiving women and their offspring.

CONCLUSIONS

Pregnancy itself is a risk factor for injuries. Injuries in pregnancy are clearly associated with an unfavorable pregnancy outcome. The recommendation "do not skydive during pregnancy" is the safest approach. A possible lesser risk alternative to skydiving could be wind-tunnel training.

CLINICAL RELEVANCE

This article provides insights into the pregnant skydiver's decision making regarding the sports. In combination with the literature review, we provide up-to-date easy to understand information on the possible risk factors. This is a valuable source of information for the care providers of female skydivers to understand and compare the risk factors of this sport. With this information, the professional recommendation and relationship are strengthened. This article also guides the need for further research. Possible research areas include pregnancy and sports-related risk factors, placentation and prenatal programming, physical and psychological factors associated with skydiving.

Fetal aortic distensibility, compliance and pulse pressure assessment during the second half of pregnancy

The objective of the study was to measure fetal aortic pulse wave velocity and lumen diameter waveforms and subsequently calculate local distensibility, compliance and pulse pressure. A dedicated algorithm for optimizing lumen diameter assessment from radiofrequency ultrasound data is described. Biplane raw data were obtained from a matrix array transducer. We evaluated 83 confirmed, normally developing pregnancies at 22-38 wk. Fetal aortic pulse wave velocity (PWV, m/s) = 0.047 × gestational age (wk) + 1.241, and the distensibility coefficient (1/kPa) = 1/(1.04 × PWV(2)). The logarithm of the local compliance index (mm(2)/kPa) and the pulse pressure (kPa) were both linearly related to gestational age as 0.022 × GA (wk) - 0.343 and 0.012 × GA (wk) + 0.931, respectively. In conclusion, fetal aortic elastic properties can be derived from phase-sensitive radiofrequency data and multiline diameter assessment. Future studies may shed further light on the developmental origins of vascular health and disease.

Cardiovascular and metabolic influences of fetal smoke exposure

Many epidemiological studies showed associations of low birth weight with cardiovascular disease, type 2 diabetes and obesity. The associations seem to be consistent and stronger among subjects with a postnatal catch up growth. It has been suggested that developmental changes in response to adverse fetal exposures might lead to changes in the fetal anatomy and physiology. These adaptations may be beneficial for short term, but may lead to common diseases in adulthood. Maternal smoking during pregnancy is one of the most important adverse fetal exposures in Western countries, and is known to be associated with a 150-200 g lower birth weight. An accumulating body of evidence suggests that maternal smoking during pregnancy might be involved in pathways leading to both low birth weight and common diseases, including cardiovascular disease, type 2 diabetes and obesity, in adulthood. In this review, we discuss epidemiological studies focused on the associations of maternal smoking with fetal growth and development and cardiovascular and metabolic disease in later life. We also discuss potential biological mechanisms, and challenges for future epidemiological studies.

Cardiovascular and metabolic influences of fetal smoke exposure

Many epidemiological studies showed associations of low birth weight with cardiovascular disease, type 2 diabetes and obesity. The associations seem to be consistent and stronger among subjects with a postnatal catch up growth. It has been suggested that developmental changes in response to adverse fetal exposures might lead to changes in the fetal anatomy and physiology. These adaptations may be beneficial for short term, but may lead to common diseases in adulthood. Maternal smoking during pregnancy is one of the most important adverse fetal exposures in Western countries, and is known to be associated with a 150–200 g lower birth weight. An accumulating body of evidence suggests that maternal smoking during pregnancy might be involved in pathways leading to both low birth weight and common diseases, including cardiovascular disease, type 2 diabetes and obesity, in adulthood. In this review, we discuss epidemiological studies focused on the associations of maternal smoking with fetal growth and development and cardiovascular and metabolic disease in later life. We also discuss potential biological mechanisms, and challenges for future epidemiological studies.

Early influences on cardiovascular and renal development

The hypothesis that a developmental component plays a role in subsequent disease initially arose from epidemiological studies relating birth size to both risk factors for cardiovascular disease and actual cardiovascular disease prevalence in later life. The findings that small size at birth is associated with an increased risk of cardiovascular disease have led to concerns about the effect size and the causality of the associations. However, recent studies have overcome most methodological flaws and suggested small effect sizes for these associations for the individual, but an potential important effect size on a population level. Various mechanisms underlying these associations have been hypothesized, including fetal undernutrition, genetic susceptibility and postnatal accelerated growth. The specific adverse exposures in fetal and early postnatal life leading to cardiovascular disease in adult life are not yet fully understood. Current studies suggest that both environmental and genetic factors in various periods of life may underlie the complex associations of fetal growth retardation and low birth weight with cardiovascular disease in later life. To estimate the population effect size and to identify the underlying mechanisms, well-designed epidemiological studies are needed. This review is focused on specific adverse fetal exposures, cardiovascular adaptations and perspectives for new studies.