Long-term cardiometabolic health in people born after assisted reproductive technology: a multi-cohort analysis

Infertility treatment and offspring blood pressure-a systematic review and meta-analysis

BACKGROUND

Studies have inconsistently observed that children conceived by IVF or ICSI have higher blood pressure compared to children not conceived by these ARTs.

OBJECTIVE AND RATIONALE

The aim was to perform a systematic review and meta-analysis of blood pressure measures of offspring conceived by ART and those conceived naturally. Resolving the suspicion of ART as a risk factor of higher blood pressure, and therefore of heart disease, has public health and clinical implications.

SEARCH METHODS

A biomedical librarian searched the Embase, PubMed, and Web of Science databases. Searches were limited to records published in English since 1978. Grey literature was searched. Inclusion criteria were humans born via infertility treatment (vs no treatment) who underwent a blood pressure assessment. Exclusion criteria were non-human participants, non-quantitative studies, absence of a control group, and specialty populations (e.g. cancer patients only). Two reviewers independently screened each record's title and abstract and full text using Covidence, extracted data using Excel, and assessed bias using the National Heart, Lung, and Blood Institute's Quality Assessment Tool for cohort studies.

OUTCOMES

Of 5082 records identified, 79 were included in the systematic review and 36 were included in the meta-analysis of systolic blood pressure (SBP) and diastolic blood pressure (DBP) in ART and non-ART groups. Overall, 34 reports including 40 effect sizes from 25 unique cohorts, compared blood pressure between ART (N = 5229) and non-ART (N = 8509, reference) groups with no covariate adjustment. No standardized mean differences (SMD) in SBP (0.06 per SD of mmHg, 95% CI = -0.05, 0.18) or DBP (0.11, 95% CI = -0.04, 0.25) by treatment were found, but the heterogeneity was considerable (I2=76% for SBP and 87% for DBP). Adjusted analyses were presented in 12 reports, representing 28 effect sizes from 21 unique cohorts (N = 2242 treatment vs N = 37 590 non-treatment). Studies adjusted for varied covariates including maternal (e.g. age, education, body mass index, smoking, pregnancy complications), child (e.g. sex, age, physical activity, BMI, height), and birth characteristics (e.g. birth weight and gestational age). Adjusted results similarly showed no SMD for SBP (-0.03, 95% CI = -0.13, 0.08) or DBP (0.02, 95% CI = -0.12, 0.16), though heterogeneity remained high (I2 = 64% and 86%). Funnel plots indicated a slight publication bias, but the trim and fill approach suggested no missing studies. Removal of five studies which adjusted for birth outcomes (potentially over-adjusting for mediators) made no material difference. Type of treatment (e.g. IVF vs ICSI), period effects by birth year (≤2000 vs >2000), offspring age group (<8, 8-14, 15+), or study location (e.g. Europe) did not modify the results.

WIDER IMPLICATIONS

In conclusion, conception by ART was not associated with offspring blood pressure in a meta-analysis, although considerable heterogeneity was observed. Given the increasing number of children born using ART, perpetuating a difference in blood pressure would mean unnecessary risk screening for many children/adults on a population level. At a clinical level, couples considering these reproductive technologies have some reassurance that there is no evidence of strong vascular 'programming' due to the techniques used.

REGISTRATION NUMBER

PROSPERO No. CRD42022374232.

Reflections on appropriately liberalizing ART for groups requiring special attention in China

PURPOSE

The continuous advancement of assisted reproductive technologies (ART) and the evolving attitudes towards marriage and fertility among the general public have led to an increasing number of groups requiring special attention (GRSA) desiring to fulfill their reproductive needs through these technologies. These groups include single women (including single mothers without children), same-sex couples, and women in high-risk occupations, among others. The purpose of this paper is to explore the feasibility of appropriately liberalizing ART for GRSA.

METHODS

This paper discusses the advantages of a moderate liberalization of ART for GRSA from two perspectives: a theoretical basis and a practical significance level. It also analyzes the current constraints on liberalizing ART and presents suggestions for moderate liberalization.

RESULTS

The moderate liberalization of ART can provide technical support for respecting and realizing the reproductive freedom of GRSA, which has certain theoretical and practical significance. However, it is also subject to constraints.

CONCLUSION

We call for government to keep pace with the times, based on the current stage of political, economic, and social development, to further recognize and protect citizens' reproductive rights, prioritize the practical needs of the public, and explore policies and regulations for gradually loosening the restrictions on ART for GRSA.

Parental infertility and offspring cardiometabolic trajectories: a pooled analysis of three European cohorts

OBJECTIVE

To assess whether parental infertility is associated with differences in cardiometabolic trajectories in offspring.

DESIGN

Pooled observational analysis in three prospective cohorts.

SETTING

Three nationwide pregnancy cohorts.

PATIENTS

A total of 14,609 singletons from the UK Avon Longitudinal Study of Parents and Children, the Portuguese Geraçao 21, and the Amsterdam Born Children and Their Development study. Each cohort contributed data up to ages 26, 12, and 13 years, respectively.

INTERVENTION

Parental infertility is defined as time-to-pregnancy of ≥12 months (n = 1,392, 9.5%).

MAIN OUTCOME MEASURES

Trajectories of body mass index (BMI), waist circumference, systolic blood pressure, diastolic blood pressure, low-density lipoprotein cholesterol (LDL-C) level, high-density lipoprotein cholesterol (HDL-C) level, triglycerides level, and glucose level were compared in the offspring of couples with and without infertility. Trajectories were modeled using mixed-effects models with natural cubic splines adjusting for cohort, sex of the offspring, and maternal factors (age, BMI, smoking, educational level, parity, and ethnicity). Predicted levels of cardiometabolic traits up to 25 years of age were compared with parental infertility.

RESULTS

Offspring of couples with infertility had increasingly higher BMI (difference in mean predicted levels by age 25 years: 1.09 kg/m2, 95% confidence interval [0.68-1.50]) and suggestively higher diastolic blood pressure at age 25 years (1.21 mmHg [-0.003 to 2.43]). Their LDL-C tended to be higher, and their HDL-C values tended to be lower over time (age: 25 years, LDL-C: 4.07% [-0.79 to 8.93]; HDL-C: -2.78% [-6.99 to 1.43]). At age 17 years, offspring of couples with infertility had higher waist circumference (1.05 cm [0.11-1.99]) and systolic blood pressure (age: 17 years; 0.93 mmHg [0.044-1.81]), but these differences attenuated at later ages. No intergroup differences in triglyceride and glucose level trajectories were observed. Further adjustment for paternal age, BMI, smoking, and educational level, and both parents' histories of diabetes and hypertension in the cohort with this information available (Avon Longitudinal Study of Parents and Children) did not attenuate intergroup differences.

CONCLUSION

Offspring of couples with infertility relative to those of fertile couples have increasingly higher BMI over the years, suggestively higher blood pressure levels, and tend to have greater values of LDL-C and lower values of HDL-C with age.

Associations of parental preconception and maternal pregnancy urinary phthalate biomarker and bisphenol-a concentrations with child eating behaviors

BACKGROUND

Eating behaviors are controlled by the neuroendocrine system. Whether endocrine disrupting chemicals have the potential to affect eating behaviors has not been widely studied in humans. We investigated whether maternal and paternal preconception and maternal pregnancy urinary phthalate biomarker and bisphenol-A (BPA) concentrations were associated with children's eating behaviors.

METHODS

We used data from mother-father-child triads in the Preconception Environmental exposure And Childhood health Effects (PEACE) Study, an ongoing prospective cohort study of children aged 6-13 years whose parent(s) previously enrolled in a fertility clinic-based prospective preconception study. We quantified urinary concentrations of 11 phthalate metabolites and BPA in parents' urine samples collected preconceptionally and during pregnancy. Parents rated children's eating behavior using the Child Eating Behavior Questionnaire (CEBQ). Using multivariable linear regression, accounting for correlation among twins, we estimated covariate-adjusted associations of urinary phthalate biomarkers and BPA concentrations with CEBQ subscale scores.

RESULTS

This analysis included 195 children (30 sets of twins), 160 mothers and 97 fathers; children were predominantly non-Hispanic white (84%) and 53% were male. Paternal and maternal preconception monobenzyl phthalate (MBzP) concentrations and maternal preconception mono-n-butyl phthalate (MnBP) were positively associated with emotional overeating, food responsiveness, and desire to drink scores in children (β's= 0.11 [95% CI: 0.01, 0.20]-0.21 [95% CI: 0.10, 0.31] per loge unit increase in phthalate biomarker concentration). Paternal preconception BPA concentrations were inversely associated with scores on food approaching scales. Maternal pregnancy MnBP, mono-isobutyl phthalate (MiBP) and MBzP concentrations were associated with increased emotional undereating scores. Maternal pregnancy monocarboxy-isononyl phthalate concentrations were related to decreased food avoiding subscale scores.

CONCLUSIONS

In this cohort, higher maternal and paternal preconception urinary concentrations of some phthalate biomarkers were associated with increased food approaching behavior scores and decreased food avoiding behavior scores, which could lead to increased adiposity in children.

Blood pressure and lipid profiles in children born after ART with frozen embryo transfer

STUDY QUESTION

Are blood pressure (BP) and lipid profiles different between children conceived after ART with frozen embryo transfer (FET), fresh embryo transfer (fresh-ET), and natural conception (NC)?

SUMMARY ANSWER

Girls conceived after FET had significantly higher systolic BP and heart rate compared with girls born after fresh-ET; boys conceived after FET had a slightly more favourable lipid profile compared with boys born after fresh-ET and NC.

WHAT IS KNOWN ALREADY

Children conceived after ART with FET are more often born large for gestational age (LGA). LGA in general increases the risk of obesity, diabetes, and cardiovascular disease later in life. Studies on mice and humans on the whole ART population have raised concerns about premature vascular ageing and higher BP. The cardiovascular health of children born after FET is scarcely explored and the results are diverging.

STUDY DESIGN SIZE DURATION

This study was part of the cohort study 'Health in Childhood following Assisted Reproductive Technology' (HiCART), which included 606 singletons (292 boys) born between December 2009 and December 2013: 200 children were conceived after FET; 203 children were conceived after fresh-ET; and 203 children were conceived naturally and matched for birth year and sex. The study period lasted from January 2019 to September 2021.

PARTICIPANTS/MATERIALS SETTING METHODS

The included children were 7-10 years of age at examination and underwent a clinical examination with anthropometric measurements, pubertal staging, and BP measurement. Additionally, a fasting blood sample was collected and analysed for cholesterol, low-density lipoproteins (LDL), high-density lipoproteins (HDL), and triglycerides. Systolic and diastolic BP were converted to standard deviation scores (SDS) using an appropriate reference and accounting for height (SDS) of the child. The three study groups were compared pairwise using a univariate linear regression model. Mean differences were adjusted for confounders using multiple linear regression analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

Girls and boys conceived after FET had significantly higher birthweight (SDS) compared with naturally conceived peers (mean difference: girls: 0.35, 95% CI (0.06-0.64), boys: 0.35, 95% CI (0.03-0.68)). Girls conceived after FET had significantly higher systolic BP (SDS) and heart rate compared with girls conceived after fresh-ET (adjusted mean difference: systolic BP (SDS): 0.25 SDS, 95% CI (0.03-0.47), heart rate: 4.53, 95% CI (0.94-8.13)). Regarding lipid profile, no significant differences were found between the three groups of girls. For the boys, no significant differences were found for BP and heart rate. Lipid profiles were more favourable in boys born after FET compared with both boys conceived after fresh-ET and NC. All outcomes were adjusted for parity, maternal BMI at early pregnancy, smoking during pregnancy, educational level, birthweight, breastfeeding, child age at examination, and onset of puberty.

LIMITATIONS REASONS FOR CAUTION

The participation rate varied from 18 to 42% in the three groups, and therefore selection bias cannot be excluded. However, extensive non-participant analyses were performed that showed almost no differences in background characteristics between participants and non-participants in the three groups, making selection bias less likely.

WIDER IMPLICATIONS OF THE FINDINGS

The higher birthweight in children conceived after FET was associated with increased systolic BP (SDS) and heart rate in girls conceived after FET compared with fresh-ET. This may be an early indicator of compromised long-term cardiovascular health in this group. The study was not powered to investigate these outcomes and further studies are therefore warranted to confirm the findings.

STUDY FUNDING/COMPETING INTERESTS

The study was funded by the Novo Nordisk Foundation (grant number: NNF18OC0034092, NFF19OC0054340) and Rigshospitalets Forskningsfond. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT03719703.

Ultrasound evaluation of the cardiovascular system in offspring conceived through assisted reproductive technology

With the widespread application of assisted reproductive technology, the health issues of offspring conceived through assisted reproductive technology have also received increasing attention. Animal experiments and clinical studies have found subclinical adverse changes in the cardiovascular system of assisted reproductive offspring. Assisted reproductive technology itself may be just one of the many factors contributing to this phenomenon, with epigenetics playing an important role. Ultrasound technology can be used to assess the morphological structure and function of the cardiovascular system in assisted reproductive offspring from the fetal stage, providing the possibility to study the potential cardiovascular damage in this large population. This review aims to explore the effects and mechanisms of assisted reproductive technology on the cardiovascular system of offspring and provide a review of the research progress in ultrasound technology in this area.

Cardiovascular health of offspring conceived by assisted reproduction technology: a comprehensive review

Recently, the use of assisted reproductive technology (ART) has rapidly increased. As a result, an increasing number of people are concerned about the safety of offspring produced through ART. Moreover, emerging evidence suggests an increased risk of cardiovascular disease (CVD) in offspring conceived using ART. In this review, we discuss the epigenetic mechanisms involved in altered DNA methylation, histone modification, and microRNA expression, as well as imprinting disorders. We also summarize studies on cardiovascular changes and other risk factors for cardiovascular disease, such as adverse intrauterine environments, perinatal complications, and altered metabolism following assisted reproductive technology (ART). Finally, we emphasize the epigenetic mechanisms underlying the increased risk of CVD in offspring conceived through ART, which could contribute to the early diagnosis and prevention of CVD in the ART population.