Effect of Advanced Maternal Age on Pregnancy Outcomes and Vascular Function in the Rat

IVF and obstetric outcomes among women of advanced maternal age (≥45 years) using donor eggs

RESEARCH QUESTION

Does very advanced maternal age (VAMA; age ≥45 years) influence obstetric outcomes among women using donor oocytes in IVF?

DESIGN

This retrospective cohort study analysed data from a nationwide IVF registry in Taiwan, focusing on IVF cycles involving women aged 45 years and older using donated oocytes between 2007 and 2016. The study assessed cumulative live birth rates (CLBR) and secondary outcomes such as clinical pregnancy, miscarriage, live birth and twin pregnancy rates, alongside perinatal outcomes such as Caesarean section rates, pre-eclampsia, gestational diabetes and birthweight.

RESULTS

The study included 1226 embryo transfer cycles from 745 women, with a stable live birth rate of about 40% across the study period. The CLBR was slightly lower in women aged 50 years and older (54.2%) compared with those aged 45-46 years (58.0%), but these differences were not statistically significant (P = 0.647). Secondary outcomes and perinatal outcomes did not significantly differ across age groups. Regression analysis suggested a non-significant trend towards a decrease in live birth rate and birthweight with increasing maternal age. The study also found that single-embryo transfer (SET) minimized the risk of twin pregnancies without significantly affecting live birth rates.

CONCLUSIONS

IVF with donor oocytes remains a viable option for women of VAMA, with consistent live birth rates across age groups. However, the study underscores the importance of elective SET to reduce the risk of twin pregnancies and associated adverse outcomes. Further research is needed to explore the impact of other factors such as paternal age and embryo development stage on IVF success in this population.

Effect of advanced maternal age on ischemic stroke vulnerability in aged rats: Investigating on blood-brain barrier permeability and gene expression

Background

Advanced maternal age (AMA), commonly defined as pregnancy at or above 35 years old. Based on the evidence, this trend has raised concerns about potential health consequences for mothers, particularly in relation to ischemic stroke. Studies suggest that AMA may be associated with a higher risk of ischemic stroke in women due to physiological changes that impact vascular health and increase cardiovascular risk factors. The aim of this study was to investigate the effect of AMA on the extent of damage after ischemic stroke in aged rats.

Methods

Female rats that gave birth at an old age (10 months) and at a young age (4 months) were subjected to ischemic stroke in old age (20 months) and subsequently compared.We assessed neurological deficits, infarct volume, blood-brain barrier (BBB) permeability, TNF-alpha levels, total oxidant capacity, and gene expressions that play a role in BBB integrity (VEGF, Occludin, and MMP-9) following ischemic stroke.

Results

There were significantly elevated levels of MMP-9 expression and reduced levels of occludin in AMA rats. Additionally, AMA rats had significantly higher levels of TNF-alpha and total oxidant capacity after experiencing an ischemic stroke. AMA rats showed significantly higher brain water content (BBB permeability), infarct volume, and neurological deficits compared to young-aged pregnancies.

Discussion

Complex relationship between pregnancy-related physiological changes, aging, vascular gene expression, and inflammatory factors may play a role in the increased vulnerability observed in older pregnant rats. The similarities between pregnancy-related alterations and aging highlight the influence of advanced maternal age on susceptibility to ischemic stroke.

Guidelines for assessing maternal cardiovascular physiology during pregnancy and postpartum

Maternal mortality rates are at an all-time high across the world and are set to increase in subsequent years. Cardiovascular disease is the leading cause of death during pregnancy and postpartum, especially in the United States. Therefore, understanding the physiological changes in the cardiovascular system during normal pregnancy is necessary to understand disease-related pathology. Significant systemic and cardiovascular physiological changes occur during pregnancy that are essential for supporting the maternal-fetal dyad. The physiological impact of pregnancy on the cardiovascular system has been examined in both experimental animal models and in humans. However, there is a continued need in this field of study to provide increased rigor and reproducibility. Therefore, these guidelines aim to provide information regarding best practices and recommendations to accurately and rigorously measure cardiovascular physiology during normal and cardiovascular disease-complicated pregnancies in human and animal models.

Advanced maternal age alters cardiac functional and structural adaptations to pregnancy in rats

A significant number of pregnancies occur at advanced maternal age (>35 yr), which is a risk factor for pregnancy complications. Healthy pregnancies require massive hemodynamic adaptations, including an increased blood volume and cardiac output. There is growing evidence that these cardiovascular adaptations are impaired with age, however, little is known about maternal cardiac function with advanced age. We hypothesized that cardiac adaptations to pregnancy are impaired with advanced maternal age. Younger (4 mo; ∼early reproductive maturity in humans) and aged (9 mo; ∼35 yr in humans) pregnant Sprague-Dawley rats were assessed and compared with age-matched nonpregnant controls. Two-dimensional echocardiographic images were obtained (ultrasound biomicroscopy; under anesthesia) on gestational day 19 (term = 22 days) and compared with age-matched nonpregnant rats (n = 7-9/group). Left ventricular structure and function were assessed using short-axis images and transmitral Doppler signals. During systole, left ventricular anterior wall thickness increased with age in the nonpregnant rats, but there was no age-related difference between the pregnant groups. There were no significant pregnancy-associated differences in left ventricular wall thickness. Calculated left ventricular mass increased with age in nonpregnant rats and increased with pregnancy only in young rats. Compared with young pregnant rats, the aortic ejection time of aged pregnant rats was greater and Tei index was lower. Overall, the greater aortic ejection time and lower Tei index with age in pregnant rats suggest mildly altered cardiac adaptations to pregnancy with advanced maternal age, which may contribute to adverse outcomes in advanced maternal age pregnancies.NEW & NOTEWORTHY We demonstrated that even before the age of reproductive senescence, rats show signs of age-related alterations in cardiac structure that suggests increased cardiac work. Our data also demonstrate, using an in vivo echocardiographic approach, that advanced maternal age in a rat model is associated with altered cardiac function and structure relative to younger pregnant controls.

Plasma Redox Balance in Advanced-Maternal-Age Pregnant Women and Effects of Plasma on Umbilical Cord Mesenchymal Stem Cells

Pregnancy at advanced maternal age (AMA) is a condition of potential risk for the development of maternal-fetal complications with possible repercussions even in the long term. Here, we analyzed the changes in plasma redox balance and the effects of plasma on human umbilical cord mesenchymal cells (hUMSCs) in AMA pregnant women (patients) at various timings of pregnancy. One hundred patients and twenty pregnant women younger than 40 years (controls) were recruited and evaluated at various timings during pregnancy until after delivery. Plasma samples were used to measure the thiobarbituric acid reactive substances (TBARS), glutathione and nitric oxide (NO). In addition, plasma was used to stimulate the hUMSCs, which were tested for cell viability, reactive oxygen species (ROS) and NO release. The obtained results showed that, throughout pregnancy until after delivery in patients, the levels of plasma glutathione and NO were lower than those of controls, while those of TBARS were higher. Moreover, plasma of patients reduced cell viability and NO release, and increased ROS release in hUMSCs. Our results highlighted alterations in the redox balance and the presence of potentially harmful circulating factors in plasma of patients. They could have clinical relevance for the prevention of complications related to AMA pregnancy.

Advanced maternal age-related clustering of metabolic abnormalities is associated with risks of adverse pregnancy outcomes

AIMS

Advanced maternal age (AMA) is correlated with higher risk of adverse pregnancy outcomes while the pathophysiology remains unclear. Our study aimed to investigate whether AMA is linked to the clustering of metabolic abnormalities, which in turn is associated with an increased risk of adverse pregnancy outcomes.

METHOD

A total of 857 pregnant woman were recruited in a prospective cohort at National Taiwan University Hospital, from November 2013 to April 2018. Metabolic abnormalities during pregnancy were defined as following: fasting plasma glucose ≥92 mg/dl, body mass index (BMI) ≥24 kg/m2, plasma high-density lipoprotein cholesterol <50 mg/dl, hyper-triglyceridemia (≥140 mg/dl in the first trimester or ≥220 mg/dl in the second trimester), and blood pressure ≥130/85 mmHg.

RESULT

Incidence of large for gestational age (LGA), primary caesarean section (CS), and the presence of any adverse pregnancy outcome increased with age. The advanced-age group tended to have more metabolic abnormalities in both the first and the second trimesters. There was a significant association between the number of metabolic abnormalities in the first and the second trimesters and the incidence of LGA, gestational hypertension or preeclampsia, primary CS, preterm birth, and the presence of any adverse pregnancy outcome, adjusted for maternal age.

CONCLUSION

AMA is associated with clustering of metabolic abnormalities during pregnancy, and clustering of metabolic abnormalities is correlated with increased risk of adverse pregnancy outcomes.

In vivo mitochondria-targeted protection against uterine artery vascular dysfunction and remodelling in rodent hypoxic pregnancy

Gestational hypoxia adversely affects uterine artery function, increasing complications. However, an effective therapy remains unidentified. Here, we show in rodent uterine arteries that hypoxic pregnancy promotes hypertrophic remodelling, increases constrictor reactivity via protein kinase C signalling, and triggers compensatory dilatation via nitric oxide-dependent mechanisms and stimulation of large conductance Ca2+ -activated K+ -channels. Maternal in vivo oral treatment with the mitochondria-targeted antioxidant MitoQ in hypoxic pregnancy normalises uterine artery reactivity and prevents vascular remodelling. From days 6-20 of gestation (term ∼22 days), female Wistar rats were randomly assigned to normoxic or hypoxic (13-14% O2 ) pregnancy ± daily maternal MitoQ treatment (500 µm in drinking water). At 20 days of gestation, maternal, placental and fetal tissue was frozen to determine MitoQ uptake. The uterine arteries were harvested and, in one segment, constrictor and dilator reactivity was determined by wire myography. Another segment was fixed for unbiased stereological analysis of vessel morphology. Maternal administration of MitoQ in both normoxic and hypoxic pregnancy crossed the placenta and was present in all tissues analysed. Hypoxia increased uterine artery constrictor responses to norepinephrine, angiotensin II and the protein kinase C activator, phorbol 12,13-dibutyrate. Hypoxia enhanced dilator reactivity to sodium nitroprusside, the large conductance Ca2+ -activated K+ -channel activator NS1619 and ACh via increased nitric oxide-dependent mechanisms. Uterine arteries from hypoxic pregnancy showed increased wall thickness and MitoQ treatment in hypoxic pregnancy prevented all effects on uterine artery reactivity and remodelling. The data support mitochondria-targeted therapy against adverse changes in uterine artery structure and function in high-risk pregnancy. KEY POINTS: Dysfunction and remodelling of the uterine artery are strongly implicated in many pregnancy complications, including advanced maternal age, maternal hypertension of pregnancy, maternal obesity, gestational diabetes and pregnancy at high altitude. Such complications not only have immediate adverse effects on the growth of the fetus, but also they can also increase the risk of cardiovascular disease in the mother and offspring. Despite this, there is a significant unmet clinical need for therapeutics that treat uterine artery vascular dysfunction in adverse pregnancy. Here, we show in a rodent model of gestational hypoxia that in vivo oral treatment of the mitochondria-targeted antioxidant MitoQ protects against uterine artery vascular dysfunction and remodelling, supporting the use of mitochondria-targeted therapy against adverse changes in uterine artery structure and function in high-risk pregnancy.

The role of maternal age on adverse pregnancy outcomes among primiparous women with singleton birth: a retrospective cohort study in urban areas of China

BACKGROUND

Both young and advanced maternal age pregnancies have strong associations with adverse pregnancy outcomes; however, there is limited understanding of how these associations present in an urban environment in China. This study aimed to analyze the associations between maternal age and pregnancy outcomes among Chinese urban women.

METHODS

We performed a population-based study consisting of 60,209 singleton pregnancies of primiparous women whose newborns were delivered after 20 weeks' gestation between January 2012 and December 2015 in urban areas of China. Participants were divided into six groups (19 or younger, 20-24, 25-29, 30-34, 35-39, 40 or older). Pregnancy outcomes include gestational diabetes mellitus (GDM), preeclampsia, placental abruption, placenta previa, premature rupture of membrane (PROM), postpartum hemorrhage, preterm birth, low birthweight, small for gestational age (SGA), large for gestational age (LGA), fetal distress, congenital microtia, and fetal death. Logistic regression models were used to assess the role of maternal age on the risk of adverse pregnancy outcomes with women aged 25-29 years as the reference group.

RESULTS

The risks of GDM, preeclampsia, placenta previa, and postpartum hemorrhage were decreased for women at a young maternal age and increased for women with advanced maternal age. Both young and advanced maternal age increased the risk of preterm birth and low birthweight. Young maternal age was also associated with increased risk of SGA (aOR 1.64, 95% CI 1.46-1.83) and fetal death (aOR 2.08, 95% CI 1.35-3.20). Maternal age over 40 years elevated the odds of placental abruption (aOR 3.44, 95% CI 1.47-8.03), LGA (aOR 1.47, 95% CI 1.09-1.98), fetal death (aOR 2.67, 95% CI 1.16-6.14), and congenital microtia (aOR 13.92, 95% CI 3.91-49.57). There were positive linear associations between maternal age and GDM, preeclampsia, placental abruption, placenta previa, PROM, postpartum hemorrhage, preterm birth, LGA and fetal distress (all P for linear trend < .05), and a negative linear association between maternal age and SGA (P for linear trend < .001). The analysis of the associations between maternal age and adverse fetal outcomes showed U-shape for preterm birth, low birth weight, SGA, fetal death and congenital microtia (all P for quadratic trend < .001).

CONCLUSIONS

Advanced maternal age predisposes women to adverse obstetric outcomes. Young maternal age manifests a bidirectional effect on adverse pregnancy outcomes. The findings may contribute to improving women's antenatal care and management.

Commentary on: Increased stiffness of omental arteries from late pregnant women at advanced maternal age

Worldwide, pregnancy at age 35 or older, termed 'advanced maternal age (AMA)', is increasing exponentially. As the incidence of pregnancy at AMA has increased, a growing body of evidence has suggested that AMA is also associated with increased risk for adverse maternal and fetal outcomes outside of genetic anomalies. Importantly, despite the mounting evidence and the increased global risk of adverse perinatal outcomes observed, few studies have examined the potential mechanisms underlying this elevated risk in pregnant people ≥35 years of age. Wooldridge and colleagues begin to address this gap in the literature. In their recent report, they examine vessel stiffness in omental resistance vessels obtained from pregnant individuals ≥35 years of age compared with pregnant individuals <35 years of age. Omental arteries were isolated and assessed via pressure myography (mechanical properties) and histological analysis for collagen and elastin content. Overall, the findings from this investigation report that maternal resistance arteries collected from women of AMA were less compliant and had less elastin than arteries obtained from women <35 years of age, suggesting that maternal resistance vessel stiffening in AMA may contribute to increased risk of adverse pregnancy outcomes. The authors should be commended for completing these studies in human resistance vessels, which now open new avenues for investigation and provoke a cascade of questions related to maternal cardiovascular adaptations to pregnancy in women ≥35 years of age.

Increased stiffness of omental arteries from late pregnant women at advanced maternal age

Advanced maternal age (≥35 years) is a risk factor for poor pregnancy outcomes. Pregnancy requires extensive maternal vascular adaptations, and with age, our blood vessels become stiffer and change in structure (collagen and elastin). However, the effect of advanced maternal age on the structure of human resistance arteries during pregnancy is unknown. As omental resistance arteries contribute to blood pressure regulation, assessing their structure in pregnancy may inform on the causal mechanisms underlying pregnancy complications in women of advanced maternal age. Omental fat biopsies were obtained from younger (<35 years) or advanced maternal age (≥35 years) women during caesarean delivery (n = 7-9/group). Arteries (200-300 µm) were isolated and passive mechanical properties (circumferential stress and strain) assessed with pressure myography. Collagen (Masson's Trichrome) and elastin (Verhoff) were visualized histologically and % positively-stained area was assessed. Median maternal age was 32 years (range 25-34) for younger, and 38 years (range 35-42) for women of advanced maternal age. Circumferential strain was lower in arteries from advanced maternal age versus younger women but circumferential stress was not different. Omental artery collagen levels were similar, while elastin levels were lower with advanced maternal age versus younger pregnancies. The collagen:elastin ratio was greater in arteries from advanced maternal age versus younger women. In conclusion, omental arteries from women of advanced maternal age were less compliant with less elastin compared with arteries of younger controls, which may affect how vascular stressors are tolerated during pregnancy. Understanding how vascular aging affects pregnancy adaptations may contribute to better pregnancy outcomes.

Effect of the interaction between advanced maternal age and pre-pregnancy BMI on pre-eclampsia and GDM in Central China

INTRODUCTION

To investigate the independent and combined effects of advanced maternal age and pre-pregnancy body mass index (BMI) on the risk of pre-eclampsia and gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

Logistic regression models were used to estimate the OR and 95% CIs of pre-eclampsia and GDM with advanced maternal age and pre-pregnancy BMI, respectively, and the interaction between advanced maternal age and pre-pregnancy BMI. We also used causal mediation analysis to assess the mediating role of pre-pregnancy BMI on maternal age-pre-eclampsia/GDM associations.

RESULTS

In this study, 788 cases (2.31%) were diagnosed with pre-eclampsia and 5430 cases (15.92%) were diagnosed with GDM. We found that advanced maternal age was associated with a higher risk for pre-eclampsia and GDM, with adjusted ORs (aORs) of 1.74 (95% CI 1.49-2.05) and 1.76 (95% CI 1.65-1.89) after adjusting for potential confounders, respectively. In addition, maternal pre-pregnancy overweight/obesity was associated with the risk of pre-eclampsia and GDM, with the corresponding aORs of 3.64 (95% CI 3.12-4.24) and 1.71 (95% CI 1.60-1.85), respectively. We also observed the interaction between maternal age and pre-pregnancy BMI for the risk of pre-eclampsia/GDM (all p for interaction <0.001). In the mediating effect analysis, we found that maternal pre-pregnancy BMI mediated the associations between maternal age and the development of pre-eclampsia and GDM.

CONCLUSIONS

Advanced maternal age and pre-pregnancy BMI were respectively associated with the risk of pre-eclampsia/GDM, and there was an interaction between the two risk factors. In addition, we found that pre-pregnancy BMI served as a mediator of the association between advanced maternal age and the risk of pre-eclampsia/GDM, providing an essential target for the prevention of maternal overweight/obesity.

Unveiling uterine aging: Much more to learn

Uterine aging is an important factor that impacts fertility, reproductive health, and uterus-related diseases; however, it remains poorly explored. Functionally, these disturbances have been associated with an abnormal hormonal response in the endometrium and decreased endometrial receptivity. Based on emerging evidence, these alterations are mediated via the senescence of endometrial stem cells and impaired decidualization of endometrial stromal cells. Multiple molecular activities may participate in uterine aging, including oxidative stress, inflammation, fibrosis, DNA damage response, and cellular senescence. Over the past decade, several protective strategies targeting these biological processes have afforded promising results, including stem cell therapy, anti-aging drugs, and herbal medicines. However, the currently available evidence is fragmented and scattered. Here, we summarize the most recent findings regarding uterine aging, including functional and structural alterations and potential cellular and molecular mechanisms, and discuss potential protective interventions against uterine aging. Thereby, we hope to provide a comprehensive understanding of the pathophysiological processes and underlying mechanisms associated with uterine aging, as well as improve fecundity and reproductive outcomes in females of advanced reproductive age.

A comparative study on third trimester fetal biometric parameters with maternal age

Background

Advanced maternal age is an important parameter associated with increased risk of feto-maternal complications and it is an evolving trend in society for women planning for pregnancy in late ages. However there are no studies done whether advanced maternal age has its effects on expression of growth pattern in the fetus. So this study was done to compare the maternal age with the third trimester fetal biometric parameters.

Methods

This study was done in 100 antenatal women and divided into two groups: Group 1: optimal maternal age group between 21-29 years of age and Group 2: advanced maternal age 30 and above. The pre-pregnant maternal weight, gestational age and third trimester fetal biometrics using ultrasound are noted and compared between the groups.

Results

The maternal weight gain between the groups was optimal but the third trimester fetal parameters were significantly less in advanced maternal age. The abdominal circumference in optimal age group and head circumference in advanced maternal age group was closer to calculated estimated date of delivery (EDD) and would be specific in calculating the gestational age.

Conclusions

Though there is no significant difference in maternal weight gain, there are fetal growth restrictions in advanced maternal age group due to which the third trimester fetal parameters are lesser than the optimal age group. Head circumference would be specific in calculating the estimated date of delivery in advanced maternal age group.

Advanced Maternal Age Impairs Uterine Artery Adaptations to Pregnancy in Rats

Advanced maternal age (≥35 years) is associated with pregnancy complications. Aging impairs vascular reactivity and increases vascular stiffness. We hypothesized that uterine artery adaptations to pregnancy are impaired with advanced age. Uterine arteries of nonpregnant and pregnant (gestational day 20) young (4 months) and aged (9 months; ~35 years in humans) Sprague-Dawley rats were isolated. Functional (myogenic tone, n = 6−10/group) and mechanical (circumferential stress-strain, n = 10−24/group) properties were assessed using pressure myography and further assessment of elastin and collagen (histology, n = 4−6/group), and matrix metalloproteinase-2 (MMP-2, zymography, n = 6/group). Aged dams had worse pregnancy outcomes, including smaller litters and fetal weights (both p < 0.0001). Only in arteries of pregnant young dams did higher pressures (>100 mmHg) cause forced vasodilation. Across the whole pressure range (4−160 mmHg), myogenic behavior was enhanced in aged vs. young pregnant dams (p = 0.0010). Circumferential stress and strain increased with pregnancy in young and aged dams (p < 0.0001), but strain remained lower in aged vs. young dams (p < 0.05). Arteries from young nonpregnant rats had greater collagen:elastin ratios than the other groups (p < 0.05). In aged rats only, pregnancy increased MMP-2 active capacity. Altered functional and structural vascular adaptations to pregnancy may impair fetal growth and development with advanced maternal age.

The Effect of Tauroursodeoxycholic Acid (TUDCA) Treatment on Pregnancy Outcomes and Vascular Function in a Rat Model of Advanced Maternal Age

Advanced maternal age (≥35 years) increases the risk of vascular complications in pregnancy that can result in fetal growth restriction and preeclampsia. Endoplasmic reticulum (ER) stress has been linked to adverse pregnancy outcomes in these complicated pregnancies. However, the role of ER stress in advanced maternal age is not known. We hypothesize that increased ER stress contributes to altered vascular function and poor pregnancy outcomes, and that treatment with the ER-stress inhibitor TUDCA will improve pregnancy outcomes. First, young and aged non-pregnant/pregnant rats were used to assess ER stress markers in mesenteric arteries; mesenteric artery phospho-eIF2α and CHOP expression were increased in aged dams compared to young dams. In a second study, young and aged control and TUDCA-treated dams were studied on gestational day (GD) 20 (term = 22 days). TUDCA treatment was provided via the drinking water throughout pregnancy (GD0-GD20; calculated dose of 150 mg/kg/day TUDCA). ER stress markers were quantified in mesenteric arteries, blood pressure was measured, pregnancy outcomes were recorded, mesenteric and main uterine arteries were isolated and vascular function was assessed by wire myography. Aged dams had increased phospho-eIF2α and CHOP expression, reduced fetal weight, reduced litter size, and impaired uterine artery relaxation. In the aged dams, TUDCA treatment reduced phospho-eIF2α and CHOP expression, reduced blood pressure, improved fetal body weight, and tended to improve uterine artery function compared to control-treated aged dams. In conclusion, our data illustrate the role of ER stress, as well as TUDCA as a potential therapeutic that may benefit pregnancy outcomes in advanced maternal age.

Intergenerational effects of prenatal hypoxia exposure on uterine artery adaptations to pregnancies in the female offspring

Prenatal hypoxia is a common complication of pregnancy and is associated with detrimental health outcomes, such as impaired cardiac and vascular function, in adult offspring. Exposure to prenatal hypoxia reportedly impacts the reproductive system of female offspring. Whether exposure to prenatal hypoxia influences pregnancy adaptations and outcomes in these female offspring is unknown. We hypothesised that prenatal hypoxia impairs uterine artery adaptations in pregnancies of the adult offspring. Pregnancy outcomes and uterine artery function were assessed in 14-16 weeks old non-pregnant and late pregnant (gestational day 20; term = 22 days) adult female offspring born to rats exposed to prenatal normoxia (21% oxygen) or hypoxia (11% oxygen, between days 15-21 of gestation). Compared with normoxia controls, prenatal hypoxia was associated with pregnant adult offspring having reduced placental weights in their litters, and uterine artery circumferential stress that increased with pregnancy. Overall, prenatal hypoxia adversely, albeit mildly, compromised pregnancies of adult offspring.

The Impact of Maternal Age on the Neonatal Electrocardiogram

BACKGROUND

Previous studies have suggested an increased prevalence of congenital heart disease among children born to women aged ≥35 years. In recent decades, the mother's age at childbirth has increased dramatically in industrialized countries. It has not been investigated if increasing maternal age affects the neonatal cardiac electrical system.

METHODS

The Copenhagen Baby Heart Study is a prospective general population study that performed cardiac evaluation in newborns. Electrocardiograms were analyzed with a computerized algorithm.

RESULTS

We included 16,518 newborns with normal echocardiograms (median age 11 days; range 0-30 days; 52% boys). Median maternal age at delivery was 31 years; 790 newborns were born to mothers aged between 16 and 24 years, 11,403 between 25 and 34 years, 4,279 between 35 and 44 years, and 46 newborns had mothers aged between 45 and 54 years. The QRS axis and maximum R-wave amplitude in V1 (R-V1) differed across the four maternal age groups (both p < 0.01), with absolute differences of 3.5% (114 vs. 110°) and 12% (1,152 vs. 1,015 µV), respectively, between newborns with the youngest and oldest mothers. Associations between maternal age and the QRS axis and R-V1 remained significant after multifactorial adjustment. Heart rate, PR interval, QRS duration, uncorrected QT interval, QTcBazett, and maximum amplitudes of S-V1, R-V6, and S-V6 were not associated with maternal age (all p > 0.05).

CONCLUSION

We observed a significant association between maternal age and the neonatal QRS axis and R-V1. However, the absolute differences were relatively small and maternal age is unlikely to have a clinically significant effect on the neonatal cardiac electrical system.

Altered Vascular Adaptations to Pregnancy in a Rat Model of Advanced Maternal Age

Advanced maternal age (≥35 years old) increases the risk of pregnancy complications such as preeclampsia and fetal growth restriction. We previously demonstrated vascular dysfunction and abnormal pregnancy outcomes in a rat model of advanced maternal age. However, vascular adaptations to pregnancy in aging were not studied. We hypothesize that advanced maternal age is associated with a more vasoconstrictive phenotype due to reduced nitric oxide (NO) and increased activity of matrix metalloproteinases (MMPs), contributing to impaired vascular adaptations to pregnancy. A rat model of advanced maternal age was used: young (4 months) and aged (9.5 months; ∼35 years in humans) non-pregnant and pregnant rats. On gestational day 20 (term = 22 days; non-pregnant rats were aged-matched), blood pressure and heart rate were measured (tail cuff plethysmography) and vascular function was assessed in mesenteric arteries (wire myography). Endothelium-dependent relaxation to methylcholine (MCh) was assessed in the presence/absence of nitric oxide synthase inhibitor (L-NAME), or inhibitors of endothelium-dependent hyperpolarization (EDH; apamin and TRAM-34). Vasoconstriction responses to big endothelin-1 (bigET-1), in the presence/absence of MMPs-inhibitor (GM6001) or endothelin converting enzyme (ECE-1) inhibitor (CGS35066), in addition, ET-1 responsiveness, were measured. Blood pressure was elevated only in aged non-pregnant rats (p < 0.001) compared to all other groups. MCh responses were not different, however, L-NAME decreased maximum vasodilation in young (p < 0.01) and aged pregnant rats (p < 0.001), and decreased MCh sensitivity in young non-pregnant rats (p < 0.01), without effects in aged non-pregnant rats. EDH contribution to relaxation was similar in young non-pregnant, and aged non-pregnant and pregnant rats, while EDH-mediated relaxation was absent in young pregnant rats (p < 0.001). BigET-1 responses were enhanced in aged non-pregnant (p < 0.01) and pregnant rats (p < 0.05). No significant changes in bigET-1 conversion occurred in the presence of MMP-inhibitor, whereas ECE-1 inhibition reduced bigET-1 constriction in aged rats (p < 0.01). No differences in ET-1 sensitivity were observed. In conclusion, contrary to our hypothesis, reduced blood pressure, and an increased EDH-dependent contribution to vasodilation suggest a compensatory mechanism that may reflect beneficial adaptations in these aged rats that were able to maintain pregnancy. These data increase our understanding of how the vascular adaptive pathways in pregnancy compensate for advanced maternal age.

The correlation between maternal age, parity, cardiac diastolic function and occurrence rate of pre-eclampsia

To evaluate the effect of age and parity on maternal cardiac diastolic function in second trimester among pregnant women with normal left ventricular ejection fraction. To analyze the correlation between impaired diastolic function and pre-eclampsia. It had been suggested that maternal cardiac adaptations during pregnancy differed between nulliparous and primiparous women and also varied according to age. Impaired cardiac function may precede pre-eclampsia. Therefore, we examined the effects of parity and age on cardiac diastolic function during pregnancy and whether impaired diastolic function during the second trimester correlates with pre-eclampsia. Women with singleton pregnancies at 13 + 0 to 27 + 6 weeks’ gestation and left ventricular ejection fraction (LVEF) ≥ 50% were retrospectively identified. Diastolic function parameters were assessed using transthoracic echocardiography. Pre-eclampsia was identified from medical records. The effect of age and parity on maternal cardiac diastolic function as well as the correlation between impaired diastolic function and occurrence rate of pre-eclampsia were examined. 376 pregnant women were included (median age: 30 years; median gestational age: 14 weeks; 171 primiparous women). LVEF was 66%. Impaired cardiac diastolic function was seen in 7.8% of pregnant women < 35 years compared with 28.6% of those ≥ 35 years (p = 0.000). ROC curve showed women with maternal age over 32 began to have a higher rate of impaired cardiac diastolic function (AUC = 0.704, p = 0.000, sensitivity = 54.5%, specificity = 75.3%). There was no difference in diastolic function indices between maternal women grouped by parity. Higher maternal age was an independent risk factor of declining Em (p < 0.05). Em < 13 cm/s was significantly associated with pre-eclampsia occurrence (HR 8.56; 95% CI 3.40–21.57) after being adjusted for confounders. Maternal age is an independent risk factor for diastolic function decline. There is no difference in cardiac diastolic function between nulliparous women and primiparous women. Pre-eclampsia occurrence is significantly higher in patients with impaired diastolic function at mid-gestation. The application of risk grading using diastolic function at mid-gestation may improve the survival outcomes of pregnant women.

Adverse maternal and perinatal pregnancy outcomes related to very advanced maternal age in primigravida and multigravida in the Netherlands: A population-based cohort

INTRODUCTION

The age at which women give birth is rising steadily in the western world. Advanced maternal age has been associated with adverse pregnancy outcomes. We assessed the association between advanced maternal age and the risk of adverse maternal and perinatal outcome in primigravid and multigravid women.

MATERIAL AND METHODS

The study was a population-based cohort study and included women giving birth between January 2000 and December 2018 using data from the Dutch perinatal registration of Perined. Women were divided into age groups. We compared outcomes between women of 40-44, 45-49, and over 50 years old (the study groups) with women of 25-29 years old (reference group), stratified for parity. We employed multivariable regression to correct for possible confounders including methods of conception, multiple pregnancies, ethnicity, and socio-economic status. Our primary outcomes were maternal and perinatal mortality. Secondary outcomes included common maternal and perinatal complications, as well as cesarean section rate.

RESULTS

A cohort of 3 700 326 women gave birth during the study period. Of these women, 3.2% were above 40 years of age. Maternal mortality was rare in all groups, but significantly higher in multigravid women over 50 years old. Perinatal mortality was significantly higher in all pregnancies of women over 40 years old, but not for primigravida over 50 years old. The most notable results with the steepest increase were in maternal complications. Both primigravida and multigravida over 40 years old were at a two times higher risk of perinatal mortality, cesarean section, gestational diabetes, hypertensive disorders, and a low Apgar score after 5 minutes. The risk for women over 45 was almost tripled for perinatal mortality and gestational diabetes and six times higher for cesarean section. Women over 50 years old had a seven times higher risk of cesarean section, a four times higher risk of gestational diabetes, postpartum hemorrhage, and neonatal intensive care unit admission, and a 10 times higher risk of hypertensive disorders.

CONCLUSIONS

The risk of adverse maternal and perinatal outcomes for women over 40 years old surges as age increases. A novel aspect was the consistent increased risks not only for primigravid women but also for multigravida.

The Distribution of Pregnant Women with Different Pregnancy Risks - 4 Cities, China, 2019

Summary

What is already known on this topic?

Based on different pregnancy risk levels, the implementation of the “Five-Color Management” for pregnant women can prevent adverse pregnancy outcomes and ensure the safety of mothers and infants.

What is added by this report?

The proportions of being multipara and of advanced maternal age in the 4 cities (Beijing, Chengdu, Shenzhen, and Wuhan) were 47.4% and 13.3%, respectively. The proportions of “Yellow and above” pregnancy risk ranged from 54.5% to 65.0% and ranged from 7.4% to 16.3% for “Orange and above” pregnancy risk. Among women with “Orange and above” pregnancy risk, most of them gave birth in public tertiary institutions (71.8%–79.4%).

What are the implications for public health practice?

The implementation of the “Five-Color Management” for pregnant women with different pregnancy risks should be strengthened, especially those with “Orange and red” pregnancy risk who should be hospitalized for delivery in tertiary medical institutions if they have conditions.

Associations of maternal age at the start of pregnancy with placental function throughout pregnancy: The Generation R Study

OBJECTIVE

To examine the associations of maternal age at the start of pregnancy across the full range with second and third trimester uterine and umbilical artery flow indices, and placental weight.

STUDY DESIGN

In a population-based prospective cohort study among 8271 pregnant women, we measured second and third trimester uterine artery resistance and umbilical artery pulsatility indices and the presence of third trimester uterine artery notching using Doppler ultrasound.

RESULTS

Compared to women aged 25-29.9 years, higher maternal age was associated with a higher third trimester uterine artery resistance index (difference for women 30-34.9 years was 0.10 SD (95% Confidence Interval (CI) 0.02 to 0.17), and for women aged ≥40 years 0.33 SD (95% CI 0.08 to 0.57), overall linear trend 0.02 SD (95% CI 0.01 to 0.03) per year). Compared to women aged 25-29.9 years, women younger than 20 years had an increased risk of third trimester uterine artery notching (Odds Ratio (OR) 1.97 (95% CI 1.30-3.00)). A linear trend was present with a decrease in risk of third trimester uterine artery notching per year increase in maternal age (OR 0.96 (95% CI 0.94 to 0.98)). Maternal age was not consistently associated with umbilical artery pulsatility indices or placental weight.

CONCLUSIONS

Young maternal age is associated with higher risk of third trimester uterine artery notching, whereas advanced maternal age is associated with a higher third trimester uterine artery resistance index, which may predispose to an increased risk of pregnancy complications.

Early life factors and their relevance to intima-media thickness of the common carotid artery in early adulthood

BACKGROUND

Early life factors may predispose an offspring to cardiovascular disease in later life; relevance of these associations may extend to ‟healthy" people in Western populations. We examined the prospective associations between early life factors and adult carotid intima-media thickness (IMT), a surrogate marker of atherosclerosis, in a healthy German population.

METHODS

We studied term participants (n = 265) of the DONALD Study, with bilateral sonographic measurements of IMT (4-8 measurements on both left and right carotid artery) at age 18-40 years and prospectively collected data on early life factors (maternal and paternal age at child birth, birth weight, gestational weight gain and full breastfeeding (>17weeks). Mean IMT values were averaged from mean values of both sides. Associations between early life factors and adult IMT were analyzed using multivariable linear regression models with adjustment for potential confounders.

RESULTS

Adult mean IMT was 0.56mm, SD 0.03, (range: 0.41 mm-0.78 mm). Maternal age at child birth was of relevance for adult IMT, which was sex specific: Advanced maternal age at child birth was associated with an increased adult IMT among female offspring only (β 0.03, SE 0.009 mm/decade, P = 0.003), this was not affected by adult waist circumference, BMI or blood pressure. Other early life factors were not relevant for IMT levels in males and females.

CONCLUSION

This study suggests that advanced maternal age at child birth is of prospective relevance for adult IMT levels in a healthy German population and this association may be of adverse relevance for females only.

Pregnancy complications and risk of preterm birth according to maternal age: A population-based study of delivery hospitalizations in Alberta

INTRODUCTION

Pregnancy-related medical complications are associated with a 2- to 5-fold increased risk of preterm birth (PTB), but the nature of this etiologic relation in context with maternal factors remains poorly understood. Previous studies have generally treated maternal age as a confounder but overlooked its potential as an effect modifier, whereby the magnitude of the effect of complications on PTB could differ significantly across age groups. We investigated whether advanced maternal age (≥35 years) modified the association between pregnancy complications and PTB, and compared population-attributable fractions of PTB from complications in women older vs younger than 35 years.

MATERIAL AND METHODS

We analyzed population-based, cross-sectional data from the Alberta Discharge Abstract Database for women aged 18-50 years with singleton live births in hospital between 2014 and 2017 (n = 152 246). Complications were preeclampsia, gestational diabetes, and placental disorders identified using diagnostic codes. Outcomes were spontaneous (sPTB) or iatrogenic (iPTB) PTB before 37 weeks of gestation. We estimated risk ratios and risk differences using modified Poisson and log binomial regression, respectively, adjusting for confounders (pregnancy history, comorbidities). Population-attributable fractions estimates were calculated from risk ratios. Age modification was tested using interaction terms and Z-tests.

RESULTS

Prevalence of advanced maternal age was 19.2%. Pregnancy complications and s/iPTB were more common among women aged ≥35 years. Age modified the risk of PTB from preeclampsia only, with risk differences of 9.9% (95% CI 7.2%-12.6%) in older women vs 6.1% (95% CI 4.8%-7.4%) in younger women (P-interaction = 0.012) for sPTB, and 29.5% (95% CI 26.0%-33.1%) vs 20.8% (95% CI 18.9%-22.6%, P-interaction <0.001) for iPTB. Population-attributable fractions of s/iPTB types for all complications were consistently 2%-5% larger in women aged ≥35 years, and significantly larger for preeclampsia (sPTB: 5.1% vs 2.7%, P = 0.002; iPTB: 18.8% vs 14.0%, P < 0.001) and placental disorders (sPTB: 12.5% vs 8.7%, P < 0.001; iPTB: 13.2% vs 8.9%, P < 0.001).

CONCLUSIONS

Of the pregnancy complications studied, advanced maternal age only modified the association between PTB and preeclampsia, such that older women with preeclampsia have a higher risk for s/iPTB than younger counterparts. Pregnancy complications contribute to a sizable proportion of PTBs in Alberta, especially among women aged ≥35 years. Findings may inform clinical risk assessment and population-level policy targeting PTB.

Advanced maternal age compromises fetal growth and induces sex-specific changes in placental phenotype in rats

Advanced maternal age is associated with an increased risk of pregnancy complications. It programmes sex-specific cardiovascular dysfunction in rat offspring, however the intrauterine mechanisms involved remain unknown. This study in the rat assessed the impact of advanced maternal age on placental phenotype in relation to the growth of female and male fetuses. We show that relative to young (3-4 months) dams, advanced maternal age (9.5-10 months) compromises growth of both female and male fetuses but affects the placental phenotype sex-specifically. In placentas from aged versus young dams, the size of the placental transport and endocrine zones were increased and expression of Igf2 (+41%) and placental lactogen (Prl3b1: +59%) genes were upregulated in female, but not male fetuses. Placental abundance of IGF2 protein also decreased in the placenta of males only (-95%). Moreover, in placentas from aged versus young dams, glucocorticoid metabolism (11β-hsd2: +63% and 11β-hsd1: -33%) was higher in females, but lower in males (11β-hsd2: -50% and 11β-hsd1: unaltered). There was however, no change in the placental abundance of 11β-HSD2 protein in aged versus young dams regardless of fetal sex. Levels of oxidative stress in the placenta were increased in female and male fetuses (+57% and +90%, respectively) and apoptosis increased specifically in the placenta of males from aged rat dams (+700%). Thus, advanced maternal age alters placental phenotype in a sex-specific fashion. These sexually-divergent changes may play a role in determining health outcomes of female and male offspring of aged mothers.

Pregnancy outcome in mothers over the age of 35

PURPOSE OF REVIEW

The proportion of pregnancies occurring in women of at least 35 years of age has increased from 6.2% in 1980 to 22.3% of births in 2016. This review summarizes recent epidemiological and basic scientific studies investigating the association between older maternal age and adverse pregnancy outcome(s), and clinical studies which investigate the effects of intervention to reduce adverse events.

RECENT FINDINGS

Women of at least 35 years of age have increased risk of maternal and foetal complications in pregnancy including: stillbirth, a small for gestational age baby, preterm birth, preeclampsia and maternal death. These risks increase with increasing age. The reasons for this increased risk are incompletely understood, but likely involve ageing of the maternal cardiovascular and endocrine systems which impacts upon placental function. Intervention, by induction of labour (IOL) at 39-week gestation does not increase operative deliveries or short-term adverse maternal and neonatal outcomes and would reduce perinatal mortality.

SUMMARY

The additional risks of pregnancy should be discussed with women of at least 35 years of age; additional foetal surveillance may be required in the antenatal period. The benefits and risks of IOL at 39-week gestation should be discussed with women at least 35 years of age.

Advanced maternal age and the impact on maternal and offspring cardiovascular health

Delaying pregnancy, which is on the rise, may increase the risk of cardiovascular disease in both women and their children. The physiological mechanisms that lead to these effects are not fully understood but may involve inadequate adaptations of the maternal cardiovascular system to pregnancy. Indeed, there is abundant evidence in the literature that a fetus developing in a suboptimal in utero environment (such as in pregnancies complicated by fetal growth restriction, preterm birth, and/or preeclampsia) is at an increased risk of cardiovascular disease in adulthood, the developmental origins of health and disease theory. Although women of advanced age are at a significantly increased risk of pregnancy complications, there is limited information as to whether advanced maternal age constitutes an added stressor on the prenatal environment of the fetus, and whether or not this is secondary to impaired cardiovascular function during pregnancy. This review summarizes the current literature available on the impact of advanced maternal age on cardiovascular adaptations to pregnancy and the role of maternal age on long-term health risks for both the mother and offspring.

Validation studies of a fluorescent method to measure placental glucose transport in mice

INTRODUCTION

Proper placental function is essential for optimal fetal growth in utero. Placental transfer of nutrients to the fetus can be measured using radiolabelled tracers, but non-radioactive methods have potential advantages. This study aimed to develop a fluorescence-based method to measure placental glucose transport in mice.

METHODS

Time course and localisation of the IRDye 800CW 2-deoxyglucose were recorded (Lumina IVIS Live Imaging System) following tail vein injection into anaesthetised late pregnant mice. Fluorescent signals in placental and fetal tissues were assessed after injecting conscious dams with 10 nmol IRDye 800CW 2-deoxyglucose (3, 30, 60, 120 min) or vehicle. Specificity of dye uptake was determined by comparing uptake of IRDye 800CW conjugated to 2-deoxyglucose or carboxylate, at 2 and 24 h. Finally, we assessed relationships of fetal size and umbilical blood flow velocities with relative dye uptake.

RESULTS

In late pregnant mice, uterine fluorescent signal localised rapidly over placentas and remained consistent for >1 h. Signal intensity in whole and homogenised tissues increased in fetuses and decreased in placentas after 3 min and stabilised by 30 min post-injection. Relative fetal dye uptake at 2 and 24 h was greater in littermates with the highest compared to lowest placental efficiency; signals were similar for 2-deoxyglucose- or carboxylate-conjugated dyes. Relative fetal dye uptake correlated positively with fetal weight and placental efficiency and negatively with umbilical artery resistance indices.

CONCLUSIONS

Fetal uptake of IRDye 800CW correlates with markers of placental blood flow and fetal growth, but does not specifically measure placental glucose transport.

Changing trends in the Turkish maternal deaths, with a focus on direct and indirect causes

OBJECTIVE

Our aim is to evaluate trends in the direct and indirect causes' distribution using data from National Maternal Mortality Surveillance (2012-2015).

STUDY DESIGN

A population-based retrospective review was performed on all pregnancy-associated maternal deaths in Turkey from 2012 to 2015. Causes of death were grouped into direct and indirect maternal deaths and compared in the context of distribution. Maternal mortality rate was reported. Statistics included chi-square test or Fisher's exact test for categorical variables.

RESULTS

Between 2012 and 2015 there were 812 maternal deaths. The maternal mortality rate was 15.4 deaths per 100,000 live births in 2012 as compared to 13.7 in 2015. Direct maternal deaths in Turkey declined from 59.5% in 2012 to 45% in 2015 while indirect maternal deaths increased from 45% in 2012 to 55% in 2015 (p = 0.045). The leading direct causes of maternal deaths were postpartum hemorrhage. The major indirect causes of maternal deaths were circulatory system diseases.

CONCLUSION

Direct maternal deaths in Turkey appear to be declining. This data will aid the management of maternal deaths.

Sex-specific effects of advanced maternal age on cardiovascular function in aged adult rat offspring

Pregnancy at an advanced maternal age has an increased risk of complications for both the mothers and their offspring. We have previously shown that advanced maternal age in a rat model leads to poor fetal outcomes, maternal vascular dysfunction, and hypertension, concordant with findings in humans. Moreover, offspring from aged dams had sex-specific cardiovascular dysfunction in young adulthood. However, the detrimental impact of aging on the cardiovascular system of the offspring in this model is unknown. We hypothesized that offspring born to aged dams (9.5–10 mo old) would have impaired cardiovascular function at 12 mo of age. Echocardiographic data revealed signs of mild left ventricular diastolic dysfunction in only male offspring from aged dams [isovolumetric relaxation time: 34.27 ± 2.04 in the young dam group vs. 27.61 ± 0.99 ms in the aged dam group, P < 0.01; mitral annular velocity ratio ( E′/ A′): 1.08 ± 0.04 in the young dam group vs. 0.96 ± 0.02 in the aged dam group, P < 0.05]. We have previously shown that in young adulthood (4 mo of age), male, but not female, offspring born to aged dams had impaired recovery from ischemia-reperfusion injury. Aging did not alter the susceptibility of female offspring to ischemia-reperfusion injury. Interestingly, wire myography data revealed that male offspring from aged dams had enhanced vascular sensitivity to methacholine (negative log of EC50: 7.4 ± 0.08 in young dams vs. 7.9 ± 0.11 in aged dams, P = 0.007) due, in part, to increased prostaglandin-mediated vasodilation. Despite intact endothelium-dependent relaxation, female offspring from aged dams had elevated systolic blood pressure (125.3 ± 4.2 mmHg in young dams vs. 144.0 ± 6.9 mmHg in aged dams, P = 0.03). These data highlight sex-specific mechanisms underlying cardiovascular programming in offspring born to dams of advanced age.

NEW & NOTEWORTHY Our study demonstrated that adult male and female offspring (12 mo old) born to aged dams had impaired cardiac diastolic function and increased blood pressure, respectively, signifying sex-specific differential cardiovascular effects of advanced maternal age.

Pregnancy Outcomes in Women of Advanced Maternal Age: a Retrospective Cohort Study from China

This retrospective cohort study attempts to investigate pregnancy complications and adverse pregnancy outcomes in women of advanced maternal age (AMA). Data were extracted from electronic medical records system at West China Second University Hospital of Sichuan University from January 2013 to July 2016. The study cohort consisted 8 subgroups of women on 4 different age levels (20-29 years, 30-34 years, 35-39 years and ≥40 years) and 2 different parities (primiparity and multiparity). In the study period, 38811 women gave birth at our hospital, a randomized block was used to include 2800 women of singleton pregnancy >28 gestational weeks, with 350 patients in each subgroup. Maternal complications and fetal outcomes were collected and defined according to relevant guidelines. Confounding factors representing maternal demographic characteristics were identified from previous studies and analysed in multivariate analysis. There was an increasing trend for the risks of adverse pregnancy outcomes with increasing age, especially in AMA groups. Our study showed that AMA, primiparity, maternal overweight or obesity, lower educational level and residence in rural area increased pregnancy complications and adverse fetal outcomes. Increased professional care as well as public concern is warranted.

The impact of maternal age on foetal growth patterns and newborn size

The association patterns between maternal age and foetal growth parameters as well as newborn size were analysed using a dataset of 4737 singleton term births taking place at the Viennese Danube hospital. Foetal growth patterns were reconstructed by the results of three ultrasound examinations carried out at the 11th/12th, 20th/21th and 32th/33thweek of gestation. In detail, crown-rump length, biparietal diameter, fronto-occipital diameter, head circumference, abdominal transverse diameter, abdominal anterior-posterior diameter, abdominal circumference, and femur length were determined. Birth weight, birth length and head circumference were measured immediately after birth. Young teenage mothers (≤15 years), older adolescent mothers (16-19 years), mothers of optimal age range (20-35 years) and mothers of advanced age (>35 years) differed significantly in body height, pre-pregnancy weight status and gestational weight gain. Surprisingly, the foetuses of young adolescent mothers were the largest ones during first trimester. During the second and third trimester however, the foetuses of mothers of optimal age range (20-35 years) and mothers older than 35 years showed larger biometric dimensions than adolescent mothers. According to multiple regression analyses, maternal age was significantly related to Foetal head size (ß =-0.04; 95% CI = -0,08 – 0.01; p=0.034) and abdominal dimensions (ß= 0.03; 95% CI = 0.01-0.05; p=0,011) during the second trimester and to birthweight (ß= -0.03; 95% CI= -4.40 – 0.04; p=0.050). The associations however, are quite weak and the statistical significance is maybe due to the large sample size. At the time of birth, offspring of mothers of optimal age range (20 to 35 years) is significantly larger than that of adolescent mothers and mothers of advanced age. Mothers of advanced age showed the significantly highest (p=<0.0001) prevalence (5.6%) of SGA newborns (<2500g). The small size of newborn among young adolescent mothers may be due to a competition over nutrients between the still growing mothers and the foetuses during the third trimester, while placental ageing may be responsible for smaller size of offspring among mothers of advanced age.

Increased susceptibility to cardiovascular disease in offspring born from dams of advanced maternal age

KEY POINTS

Advanced maternal age increases the risk of pregnancy complications such as fetal growth restriction, hypertension and premature birth. Offspring born from compromised pregnancies are at increased risk of cardiovascular disease as adults. However, the effect of advanced maternal age on later-onset disease in offspring has not been investigated. In adulthood, male but not female offspring born to dams of advanced maternal age showed impaired recovery from cardiac ischaemia/reperfusion injury. Endothelium-dependent relaxation was also impaired in male but not female offspring born from aged dams. Oxidative stress may play a role in the developmental programming of cardiovascular disease in this model. Given the increasing trend toward delayed parenthood, these findings have significant population and health care implications and warrant further investigation.

ABSTRACT

Exposure to prenatal stressors, including hypoxia, micro- and macronutrient deficiency, and maternal stress, increases the risk of cardiovascular disease in adulthood. It is unclear whether being born from a mother of advanced maternal age (≥35 years old) may also constitute a prenatal stress with cardiovascular consequences in adulthood. We previously demonstrated growth restriction in fetuses from a rat model of advanced maternal age, suggesting exposure to a compromised in utero environment. Thus, we hypothesized that male and female offspring from aged dams would exhibit impaired cardiovascular function as adults. In 4-month-old offspring, we observed impaired endothelium-dependent relaxation in male (P < 0.05) but not female offspring born from aged dams. The anti-oxidant polyethylene glycol superoxide dismutase improved relaxation only in arteries from male offspring of aged dams (ΔE_max : young dam -1.63 ± 0.80 vs. aged dam 11.75 ± 4.23, P < 0.05). Furthermore, endothelium-derived hyperpolarization-dependent relaxation was reduced in male but not female offspring of aged dams (P < 0.05). Interestingly, there was a significant increase in nitric oxide contribution to relaxation in females born from aged dams (ΔE_max : young dam -24.8 ± 12.1 vs. aged dam -68.7 ± 7.7, P < 0.05), which was not observed in males. Recovery of cardiac function following an ischaemia-reperfusion insult in male offspring born from aged dams was reduced by ∼57% (P < 0.001), an effect that was not evident in female offspring. These data indicate that offspring born from aged dams have an altered cardiovascular risk profile that is sex-specific. Given the increasing trend toward delaying pregnancy, these findings may have significant population and health care implications and warrant further investigation.

Reduction in Regulatory T Cells in Early Pregnancy Causes Uterine Artery Dysfunction in Mice

Preeclampsia, fetal growth restriction, and miscarriage remain important causes of maternal and perinatal morbidity and mortality. These complications are associated with reduced numbers of a specialized T lymphocyte subset called regulatory T cells (Treg cells) in the maternal circulation, decidua, and placenta. Treg cells suppress inflammation and prevent maternal immunity toward the fetus, which expresses foreign paternal alloantigens. Treg cells are demonstrated to contribute to vascular homeostasis, but whether Treg cells influence the vascular adaptations essential for a healthy pregnancy is unknown. Thus, using a mouse model of Treg-cell depletion, we investigated the hypothesis that depletion of Treg cells would cause increased inflammation and aberrant uterine artery function. Here, we show that Treg-cell depletion resulted in increased embryo resorption and increased production of proinflammatory cytokines. Mean arterial pressure exhibited greater modulation by NO in Treg cell-deficient mice because the L-N^G-nitroarginine methyl ester-induced increase in mean arterial pressure was 46% greater compared with Treg cell-replete mice. Uterine artery function, which is essential for the supply of nutrients to the placenta and fetus, demonstrated dysregulated hemodynamics after Treg-cell depletion. This was evidenced by increased uterine artery resistance and pulsatility indices and enhanced conversion of bET-1 (big endothelin-1) to the active and potent vasoconstrictor, ET-1 (endothelin-1). These data demonstrate an essential role for Treg cells in modulating uterine artery function during pregnancy and implicate Treg-cell control of maternal vascular function as a key mechanism underlying normal fetal and placental development.

Pregnancy late in rodent life has detrimental effects on the heart

During pregnancy, the heart undergoes significant and numerous changes, including hypertrophy, that are usually described as physiological and reversible. Two aspects of the cardiac response to pregnancy are relatively understudied: advanced maternal age and multiple pregnancies (multiparity). Repeated breeder (RB) mice that have undergone five to seven consecutive pregnancies were euthanized 21 days after the weaning of their last pups and compared with age-matched primiparous, one-time pregnant (O1P) mice. The ages of the older mouse groups were similar (12 ± 1 mo). Pregnancy at a later age resulted in reduced fertility (40%); resorption was 29%, maternal mortality was 10%, and mortality of the pups was 17%. Contractile function as indicated by percent fractional shortening was significantly decreased in O1P and RB groups compared with the old nonpregnant control (ONP) group. There was no pathological induction of the fetal program of gene expression, with the exception of β-myosin heavy chain mRNA, which was induced in O1P compared with ONP mice ( P < 0.05) but not in RB mice. MicroRNA-208a was significantly increased in O1P compared with ONP mice ( P < 0.05) but significantly decreased in RB compared with ONP mice ( P < 0.05). mRNA of genes regulating angiogenesis (i.e., vascular endothelial growth factor-A) were significantly downregulated, whereas proinflammatory genes [i.e., interleukin-6, chemokine (C-C motif) ligand 2, and Cd36] were significantly upregulated in O1P ( P < 0.05) but not in RB mice. Overall, our results suggest that rather than multiparity, pregnancy in advanced age is a much more stressful event in both pregnant dams and fetuses, as evidenced by increased mortality, lower fertility, downregulation of angiogenesis, upregulation of inflammation, and cardiac dysfunction. NEW & NOTEWORTHY Pregnancy in older mice significantly decreases cardiac function, although repeated breeder mice demonstrated increased wall hypertrophy and dilated chamber size compared with one-time pregnant mice. Interestingly, many of the molecular changes were altered in one-time pregnant mice but not in repeated breeder mice, which may contribute to adverse pregnancy outcomes in a first pregnancy at a later age.

Advanced maternal age and adverse pregnancy outcomes: A systematic review and meta-analysis

BACKGROUND

Advanced maternal age (AMA; ≥35 years) is an increasing trend and is reported to be associated with various pregnancy complications.

OBJECTIVE

To determine the risk of stillbirth and other adverse pregnancy outcomes in women of AMA.

SEARCH STRATEGY

Embase, Medline (Ovid), Cochrane Database of Systematic Reviews, ClinicalTrials.gov, LILACS and conference proceedings were searched from ≥2000.

SELECTION CRITERIA

Cohort and case-control studies reporting data on one or more co-primary outcomes (stillbirth or fetal growth restriction (FGR)) and/or secondary outcomes in mothers ≥35 years and <35 years.

DATA COLLECTION AND ANALYSIS

The effect of age on pregnancy outcome was investigated by random effects meta-analysis and meta-regression. Stillbirth rates were correlated to rates of maternal diabetes, obesity, hypertension and use of assisted reproductive therapies (ART).

MAIN RESULTS

Out of 1940 identified titles; 63 cohort studies and 12 case-control studies were included in the meta-analysis. AMA increased the risk of stillbirth (OR 1.75, 95%CI 1.62 to 1.89) with a population attributable risk of 4.7%. Similar trends were seen for risks of FGR, neonatal death, NICU unit admission restriction and GDM. The relationship between AMA and stillbirth was not related to maternal morbidity or ART.

CONCLUSIONS

Stillbirth risk increases with increasing maternal age. This is not wholly explained by maternal co-morbidities and use of ART. We propose that placental dysfunction may mediate adverse pregnancy outcome in AMA. Further prospective studies are needed to directly test this hypothesis.

Placental Dysfunction Underlies Increased Risk of Fetal Growth Restriction and Stillbirth in Advanced Maternal Age Women

Pregnancies in women of advanced maternal age (AMA) are susceptible to fetal growth restriction (FGR) and stillbirth. We hypothesised that maternal ageing is associated with utero-placental dysfunction, predisposing to adverse fetal outcomes. Women of AMA (≥35 years) and young controls (20-30 years) with uncomplicated pregnancies were studied. Placentas from AMA women exhibited increased syncytial nuclear aggregates and decreased proliferation, and had increased amino acid transporter activity. Chorionic plate and myometrial artery relaxation was increased compared to controls. AMA was associated with lower maternal serum PAPP-A and sFlt and a higher PlGF:sFlt ratio. AMA mice (38-41 weeks) at E17.5 had fewer pups, more late fetal deaths, reduced fetal weight, increased placental weight and reduced fetal:placental weight ratio compared to 8-12 week controls. Maternofetal clearance of 14C-MeAIB and 3H-taurine was reduced and uterine arteries showed increased relaxation. These studies identify reduced placental efficiency and altered placental function with AMA in women, with evidence of placental adaptations in normal pregnancies. The AMA mouse model complements the human studies, demonstrating high rates of adverse fetal outcomes and commonalities in placental phenotype. These findings highlight placental dysfunction as a potential mechanism for susceptibility to FGR and stillbirth with AMA.

Factors associated with maternal mortality at advanced maternal age: a population-based case-control study

OBJECTIVE

This study aimed to examine the factors associated with maternal mortality among women aged ≥35 years.

DESIGN

Unmatched population based case-control study.

SETTING

United Kingdom.

POPULATION

Between 2009 and 2012, 105 cases of maternal deaths aged ≥35 years were extracted from the surveillance database of the MBRRACE-UK confidential enquiries into maternal deaths in the UK. In addition, 766 controls aged ≥35 years were identified from the UK Obstetric Surveillance System (2005-2012).

METHODS

Risk factors known to be associated with maternal mortality and morbidity and for which data were available were examined for their association with maternal mortality among women ≥35 years using logistic regression analysis.

MAIN OUTCOME MEASURES

Odds ratios and 95% confidence intervals associated with maternal death.

RESULTS

Five factors were found to be significantly associated with increased odds of death among women aged ≥35 years: smoking during pregnancy (adjusted odds ratio (aOR) 2.06, 95% CI 1.13-3.75), inadequate use of antenatal care (aOR 23.62, 95% CI 8.79-63.45), medical co-morbidities (aOR 5.92, 95% CI 3.56-9.86) and previous pregnancy problems (aOR 2.06, 95% CI 1.23-3.45). The odds associated with death increased by 12% per year increase in age (aOR 1.12, 95% CI 1.02-1.22).

CONCLUSION

Age was associated with maternal mortality even after adjusting for other known risk factors. Importantly, this study showed an association between maternal mortality and smoking among women aged 35 years or older. It emphasises the importance of public health action to reduce smoking levels and address trends in rising maternal age.

TWEETABLE ABSTRACT

Smoking is a risk factor for maternal death for those aged over 35 years.

Advanced Maternal Age Worsens Postpartum Vascular Function

The age at which women experience their first pregnancy has increased throughout the decades. Pregnancy has an important influence on maternal short- and long-term cardiovascular outcomes. Pregnancy at an advanced maternal age increases maternal risk of gestational diabetes, preeclampsia, placenta previa and caesarian delivery; complications which predict worsened cardiovascular health in later years. Aging also independently increases the risk of cardiovascular disease; therefore, combined risk in women of advanced maternal age may lead to detrimental cardiovascular outcomes later in life. We hypothesized that pregnancy at an advanced maternal age would lead to postpartum vascular dysfunction. We used a reproductively aged rat model to investigate vascular function in never pregnant (virgin), previously pregnant (postpartum) and previously mated but never delivered (nulliparous) rats at approximately 13.5 months of age (3 months postpartum or equivalent). Nulliparous rats, in which pregnancy was spontaneously lost, demonstrated significantly reduced aortic relaxation responses (methylcholine [MCh] Emax: 54.2 ± 12.6%) vs. virgin and postpartum rats (MCh Emax: 84.8 ± 3.5% and 84.7 ± 3.2% respectively); suggesting pregnancy loss causes a worsened vascular pathology. Oxidized LDL reduced relaxation to MCh in aorta from virgin and postpartum, but not nulliparous rats, with an increased contribution of the LOX-1 receptor in the postpartum group. Further, in mesenteric arteries from postpartum rats, endothelium-derived hyperpolarization (EDH)-mediated vasodilation was reduced and a constrictive prostaglandin effect was apparent. In conclusion, aged postpartum rats exhibited vascular dysfunction, while rats which had pregnancy loss demonstrated a distinct vascular pathology. These data demonstrate mechanisms which may lead to worsened outcomes at an advanced maternal age; including early pregnancy loss and later life cardiovascular dysfunction.

Endothelial dysfunction and vascular disease - a 30th anniversary update

The endothelium can evoke relaxations of the underlying vascular smooth muscle, by releasing vasodilator substances. The best-characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO) which activates soluble guanylyl cyclase in the vascular smooth muscle cells, with the production of cyclic guanosine monophosphate (cGMP) initiating relaxation. The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDH-mediated responses). As regards the latter, hydrogen peroxide (H₂ O₂ ) now appears to play a dominant role. Endothelium-dependent relaxations involve both pertussis toxin-sensitive G_i (e.g. responses to α₂ -adrenergic agonists, serotonin, and thrombin) and pertussis toxin-insensitive G_q (e.g. adenosine diphosphate and bradykinin) coupling proteins. New stimulators (e.g. insulin, adiponectin) of the release of EDRFs have emerged. In recent years, evidence has also accumulated, confirming that the release of NO by the endothelial cell can chronically be upregulated (e.g. by oestrogens, exercise and dietary factors) and downregulated (e.g. oxidative stress, smoking, pollution and oxidized low-density lipoproteins) and that it is reduced with ageing and in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively lose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and EDH, in particular those due to H₂ O₂ ), endothelial cells also can evoke contraction of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factors. Recent evidence confirms that most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells and that prostacyclin plays a key role in such responses. Endothelium-dependent contractions are exacerbated when the production of nitric oxide is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive and diabetic patients. In addition, recent data confirm that the release of endothelin-1 can contribute to endothelial dysfunction and that the peptide appears to be an important contributor to vascular dysfunction. Finally, it has become clear that nitric oxide itself, under certain conditions (e.g. hypoxia), can cause biased activation of soluble guanylyl cyclase leading to the production of cyclic inosine monophosphate (cIMP) rather than cGMP and hence causes contraction rather than relaxation of the underlying vascular smooth muscle.