Interpregnancy interval, maternal age, and offspring's BMI and blood pressure at 7 years of age

Embryo morphologic quality in relation to the metabolic and cognitive development of singletons conceived by in vitro fertilization and intracytoplasmic sperm injection: a matched cohort study

BACKGROUND

Embryos with higher morphologic quality grading may have a greater potential to achieve clinical pregnancy that leads to a live birth regardless of the type of cleavage-stage embryos or blastocysts. Few studies have investigated the impacts of embryo grading on the long-term health of the offspring.

OBJECTIVE

This pilot study aimed to examine the associations between embryo morphologic quality and the physical, metabolic, and cognitive development of singletons conceived by in vitro fertilization and intracytoplasmic sperm injection at preschool age.

STUDY DESIGN

This matched cohort study included singletons born to infertile couples who underwent fresh cleavage-stage embryo transfer cycles with good- or poor-quality embryos from 2014 to 2016 at the reproductive center of the Women's Hospital, School of Medicine, Zhejiang University. A total of 144 children, aged 4 to 6 years, participated in the follow-up assessment from 2020 to 2021, and the response rate of poor-quality embryo offspring was 39%. Singletons in the good-quality embryo group were matched with singletons in the poor-quality embryo group at a 2:1 ratio according to the fertilization method and the children's age (±1 year). We measured the offspring's height, weight, body mass index, blood pressure, thyroid hormone levels, and metabolic indicators. Neurodevelopmental assessments were performed using the Chinese version of the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition, and the Adaptive Behavior Assessment System, Second Edition. We also collected data from the medical records. A linear regression model was used to analyze the association between embryo morphologic quality and offspring health outcomes.

RESULTS

A total of 48 singletons conceived with poor-quality embryo transfer and 96 matched singletons conceived with good-quality embryo transfer were included in the final analysis. Age, sex, height, weight, body mass index, blood pressure, thyroid function, and metabolic indicators were comparable between the 2 groups. After adjustment for potential risk factors by linear regression model 1 and model 2, poor-quality embryo offspring exhibited a tendency toward higher free thyroxine levels than offspring of good-quality embryo transfers (beta, 0.22; 95% confidence interval, 0.09-0.90; beta, 0.22; 95% confidence interval, 0.09-0.91, respectively), but this difference was not clinically significant. Regarding neurodevelopmental assessments, there was no difference in the full-scale intelligence quotient based on the Wechsler Preschool and Primary Scale of Intelligence (109.96±12.42 vs 109.60±14.46; P=.88) or the general adaptive index based on the Adaptive Behavior Assessment System (108.26±11.70 vs 108.08±13.44; P=.94) between the 2 groups. The subindices of the 2 tests were also comparable. These findings remained after linear regression analysis.

CONCLUSION

At 4 to 6 years of age, singletons born from poor-quality embryo transfers have comparable metabolic and cognitive development as those born from good-quality embryo transfers using fresh cleavage-stage embryos. The results of this pilot study indicate that poor-quality embryos that can survive implantation and end in live birth are likely to have a developmental potential comparable to that of good-quality embryos.

Interpregnancy interval and subsequent perinatal risk of congenital heart disease in Guangzhou, Southern China: a retrospective cohort study, 2014-2019

BACKGROUND

The association between maternal interpregnancy interval (IPI) and congenital heart disease (CHD) in neonates remains inconclusive. This study aimed to examine the effect of maternal IPI on birth risk of CHD.

METHODS

Chinese women with two consecutive singleton deliveries in Guangzhou between January 2014 and December 2019 were selected as participants. Information on IPI and CHD was extracted from the Guangzhou Perinatal Health Care and Delivery Registry and the Guangzhou Birth Defects Surveillance Program. We stratified IPI into four categories: <24 months, 24-35 months, 36-59 months, and ≥60 months. A multivariate logistic regression model was used to examine the association between IPI and CHD. Subgroup analysis was also performed to assess whether the associations differed across top three CHD subtypes.

RESULTS

For 119,510 women enrolled in this study, the mean ages at two consecutive deliveries were 26.2 ± 3.8 and 28.8 ± 4.0 years, which yielded a median IPI of 51.2 (interquartile range, 32.1-77.2) months. Among them, 828 delivered infants with CHD during their second pregnancy. There was a J-shaped curve relationship between IPI and CHD with the lowest birth prevalence (5.33‰) at 24-35-month interval. Compared to women with an IPI of 24-35 months, those with an IPI ≥60 had an increased risk of delivering infants with CHD (adjusted odds ratio (OR), 1.41; 95% confidence interval (CI), 1.19-1.64). However, for those with an IPI <24 months (adjusted OR, 1.24; 95% CI, 0.97-1.51), IPI was statistically insignificant associated with the risk of delivering infants with CHD (p = .12). There were different patterns of associations for different CHD subtypes.

CONCLUSIONS

Longer maternal IPI (≥60 months) was associated with an increased risk of delivering infants with CHD in the Chinese population.

Impact of interpregnancy interval on long-term childhood neoplasm of the offspring

BACKGROUND

The possible impact of interpregnancy interval (IPI) on perinatal outcomes has long been studied, however, a definition of the optimal interval is still not clear. Both short and long IPIs have been associated with obstetrical syndromes and short and long-term complications. In this study, we sought to explore the impact of IPI on the hazard for neoplasm of the offspring, thus contribute to the present literature in determining the preferred birth spacing.

OBJECTIVE

We aim to investigate the association between short and long IPIs and the hazard for childhood neoplasm of the offspring.

METHODS

A population-based retrospective cohort analysis comparing offspring neoplasm hazard following three different IPIs. Exposure was defined as short (<6 months), or long (>60 months) IPIs, whereas intermediate IPI (6 months - 60 months) served as the comparison group. The study included singleton live births in a tertiary regional hospital between 1991 and 2014. Offspring were followed for 18 years, and all hospitalization records for neoplasm diagnoses were collected. Kaplan-Meier survival curves were used for the cumulative incidence of neoplasm morbidity, and Cox proportional hazards models were used to control for confounders.

RESULTS

During the study period, 144,397 deliveries met the inclusion criteria. Of those, 18,947 (13.1%) occurred in women with short IPI, 114,012 (79%) in women with intermediate IPI, and 11,438 (7.9%) in women with long IPI. 61 benign neoplasms and 80 malignant neoplasms were registered in offspring born after long IPI. The total percentage of neoplasm were the highest in the long IPI group versus the intermediate and short IPI groups (malignant - 0.7%, 0.6%, 0.5% respectively, benign - 0.5%, 0.4%, 0.3% respectively). Controlling for maternal age, diabetes mellitus, preterm delivery, birth weight, smoking, cesarean section, and fertility treatments, long IPI was found to be independently associated with high hazard for long-term pediatric neoplasm related hospitalizations (adjusted HR 1.39, 95% CI 1.09, 1.77). Short IPI may be associated to decreased hazard for childhood neoplasms (adjusted HR 0.74, 95% Cl 0.59, 0.92).

CONCLUSIONS

Long IPI is associated with a high hazard for childhood neoplasms, compared with intermediate and short IPIs. Short IPI may be associated with decreased hazard for childhood neoplasms.

Excessive Gestational Weight Gain: Long-Term Consequences for the Child

Background: The aim of the study was to analyse the impact of mothers’ gestational weight gain (GWG) and age at birth on the long-term risk of overweight and obesity in preschool and school-aged children. Methods: The study involved 749 mothers and children at ages between four and 15 years old. Each child was assessed for height and body weight, and then, the body mass category was determined based on the body mass index (BMI) percentile according to the sex and age of the subjects. Information on the perinatal risk factors for overweight and obesity came from the child’s health card or mother’s maternity card. They contained information about the mother’s age at the time of childbirth and the mother’s gestational weight gain during pregnancy. Results: In the group of 7–11-year-olds, the maternal weight gain during pregnancy was higher in obese children than in children with normal weight (18.8 kg vs. 14.3 kg; p = 0.002). This relationship was shown analogously in the group of 7–11-years-olds boys (20.6 kg vs. 15.1 kg; p = 0.005). Positive correlations were also shown between mother’s gestational weight gain and the BMI percentage of the whole group (p = 0.004). In the case of the mother’s age, no statistically significant relationship was found with the child’s weight category. Conclusions: Mothers’ weight gain during pregnancy is a factor that promotes overweightness and obesity in the child. Maternal age at birth does not appear to lead to any propensity toward overweightness and obesity in the later life of a child.

Change in modifiable maternal characteristics and behaviours between consecutive pregnancies and offspring adiposity: A systematic review

Causal evidence links modifiable maternal exposures during the periconceptional period with offspring obesity. The interconception period may be an important time to intervene. We systematically identified studies examining change in modifiable maternal exposures between pregnancies and offspring adiposity. We searched for longitudinal studies published between 1990 and 2019, which included measurements taken on at least two occasions in the period from 1 year prior to the conception of the first birth to the time of the second birth, and which included a measure of adiposity in second, or higher order, siblings. Age, ethnicity and genetics were not considered modifiable; all other factors including length of the interpregnancy interval were. Eleven studies satisfied the inclusion criteria. Higher interpregnancy weight gain or loss, maternal smoking inception, mothers smoking in their first pregnancy and quitting, increasing the number of cigarettes smoked and longer interpregnancy intervals were positively associated with adiposity in second or higher order children. Vaginal birth after caesarean delivery was protective. Further research is needed to ascertain whether the risk of adiposity is fixed based on first pregnancy exposures or if interpregnancy change alters the risk for a subsequent child. This can inform the type and effectiveness of interventions for mothers prior to a subsequent pregnancy.

Increased risk of metabolic dysfunction in children conceived by assisted reproductive technology

AIMS/HYPOTHESIS

Assisted reproductive technology (ART) is the most widely used treatment for infertility and has resulted in millions of births worldwide. The safety of the offspring has been of the utmost concern. Previous studies suggested an increase in metabolic disorders in offspring later in life. The aim of the present study was to investigate metabolic changes at age 6-10 years in offspring conceived as a result of in vitro fertilisation/intracytoplasmic sperm injection (IVF/ICSI).

METHODS

A total of 380 children born from IVF/ICSI and a matched control group of 380 naturally conceived children, all aged 6-10 years, were recruited. Anthropometric measures, ultrasound and serum tests were performed for body mass, glucose metabolism and lipid profiles, and examination of vasculature structure.

RESULTS

The children conceived by ART showed significantly higher fasting blood glucose and serum insulin levels and HOMA-IR (adjusted β [95% CI]: fasting blood glucose 0.49 [0.42, 0.55]; log_e-transformed insulin 0.28 [0.20, 0.35]; log_e-transformed HOMA-IR 0.38 [0.30, 0.46]), as well as a lower HOMA-B and serum apolipoprotein A (ApoA) levels (adjusted β [95% CI]: log_e-transformed HOMA-B -0.19 [-0.27, -0.11]; ApoA -0.17 [-0.21, -0.13]), when compared with the control group. Furthermore, the ultrasound scan indicated elevated carotid intima-media thickness in children conceived by ART (β 0.13 [95% CI 0.12, 0.13]).

CONCLUSIONS/INTERPRETATION

Children conceived by IVF/ICSI have a less favourable glucose and cardiovascular metabolic profile in childhood when compared with naturally conceived children. The underlying mechanisms and potential long-term consequences need to be elucidated in future studies. Graphical abstract.

The effects of advanced maternal age on T-cell subsets at the maternal-fetal interface prior to term labor and in the offspring: a mouse study

Women who conceive at 35 years of age or older, commonly known as advanced maternal age, have a higher risk of facing parturition complications and their children have an increased risk of developing diseases later in life. However, the immunological mechanisms underlying these pathological processes have yet to be established. To fill this gap in knowledge, using a murine model and immunophenotyping, we determined the effect of advanced maternal age on the main cellular branch of adaptive immunity, T cells, at the maternal-fetal interface and in the offspring. We report that advanced maternal age impaired the process of labor at term, inducing dystocia and delaying the timing of delivery. Advanced maternal age diminished the number of specific proinflammatory T-cell subsets [T helper type 1 (Th1): CD4⁺ IFN-γ⁺ , CD8⁺ IFN-γ⁺ and Th9: CD4⁺ IL-9⁺ ], as well as CD4⁺ regulatory T cells (CD4⁺ CD25⁺ FoxP3⁺ T cells), at the maternal-fetal interface prior to term labor. Advanced maternal age also altered fetal growth and survival of the offspring in early life. In addition, infants born to advanced-age mothers had alterations in the T-cell repertoire but not in CD71⁺ erythroid cells (CD3^- CD71⁺ TER119⁺ cells). This study provides insight into the immune alterations observed at the maternal-fetal interface of advanced-age mothers and their offspring.

Persistent epigenetic changes in adult daughters of older mothers

Women of advanced maternal age account for an increasing proportion of live births in many developed countries across the globe. Offspring of older mothers are at an increased risk for a variety of subsequent health outcomes, including outcomes that do not manifest until childhood or adulthood. The molecular underpinnings of the association between maternal aging and offspring morbidity remain elusive. However, one possible mechanism is that maternal aging produces specific alterations in the offspring's epigenome in utero, and these epigenetic alterations persist into adulthood. We conducted an epigenome-wide association study (EWAS) of the effect of a mother's age on blood DNA methylation in 2,740 adult daughters using the Illumina Infinium HumanMethylation450 array. A false discovery rate (FDR) q-value threshold of 0.05 was used to identify differentially methylated CpG sites (dmCpGs). We identified 87 dmCpGs associated with increased maternal age. The majority (84%) of the dmCpGs had lower methylation in daughters of older mothers, with an average methylation difference of 0.6% per 5-year increase in mother's age. Thirteen genomic regions contained multiple dmCpGs. Most notably, nine dmCpGs were found in the promoter region of the gene LIM homeobox 8 (LHX8), which plays a pivotal role in female fertility. Other dmCpGs were found in genes associated with metabolically active brown fat, carcinogenesis, and neurodevelopmental disorders. We conclude that maternal age is associated with persistent epigenetic changes in daughters at genes that have intriguing links to health.