Intra-uterine growth restriction as a risk factor for hypertension in children six to 10 years old

Maternal Factors for Intrauterine Growth Retardation: Systematic Review and Meta-Analysis of Observational Studies

Intrauterine growth retardation (IUGR) is a major complication of pregnancy and is the second leading cause of perinatal morbidity and mortality. The etiology of IUGR is multifactorial and the maternal factors are easily identifiable and modifiable. The present study aimed to perform a meta-analysis to identify the association between various maternal factors and IUGR. Eight electronic databases (PubMed, Cochrane, Embase, CIHNAL Plus, CNKI, VIP database, CBM, and WanFang database) were searched from their inception until July 2020. Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. The Newcastle-Ottawa Quality Assessment Form and the Joanna Briggs Institute critical appraisal tool were used to evaluate the quality of included studies. The outcomes of study were calculated by OR with 95%CI. The study protocol was registered with PROSPERO (No. CRD42020210615). A total of 15 studies were included, with a sample size range from 152 to 9372. The quality of included studies ranged from moderate to high. The pooled results identified seven factors: smoking (OR = 1.62, 95%CI 1.38-1.90), primiparity (OR = 1.64, 95%CI 1.20-2.24), and prepregnancy.BMI < 18.5 (OR = 1.98, 95%CI 1.29-3.03), anemia (OR = 2.01, 95%CI 1.44-2.82), hypoproteinemia (OR = 2.91, 95%CI 1.94-4.36), pregnancy-induced hypertension (OR = 3.45, 95%CI 1.80-6.58), and maternal gestational weight gain (OR = 2.51, 95%CI 1.88-3.35). The present study identified several maternal factors for IUGR: smoking, primiparity, prepregnancy BMI < 18.5, poor gestational weight gain, PIH, anemia, and hypoproteinemia. The result could serve to generate risk factors prediction models, improve the management and education for child-bearing or early pregnant women.

Conflicting Effects of Fetal Growth Restriction on Blood Pressure Between Human and Rat Offspring: A Meta-Analysis

Low birth weight is associated with hypertension. Low birth weight can result from fetal growth restriction (FGR) or prematurity. FGR is postulated to impact blood pressure (BP) by developmental programming. This systematic review and meta-analysis studies BP in human and animal offspring following FGR. Pubmed and Web of Science were searched for studies reporting on BP after placental insufficiency induced FGR compared with normal growth controls. Primary outcome was mean absolute BP difference (ΔBP mm Hg [95% CI]). Meta-analysis was performed using random-effects models. Subgroup analyses were executed on species, sex, age, pregnancy duration, and stress during BP readings. Due to large interspecies heterogeneity, analyses were performed separately for human (n=41) and animal (n=31) studies, the latter restricted to rats (n=27). Human studies showed a ΔBP between FGR and controls of -0.6 mm Hg ([95% CI, -1.7 to 0.6]; I²=91%). Mean ΔBP was -2.6 mm Hg (95% CI, -5.7 to 0.4) in women versus -0.5 mm Hg (95% CI, -3.7 to 2.7) in men. Subgroup analyses did not indicate age, gestational age, and stress during measurements as sources of heterogeneity. In rats, mean BP was 12.0 mm Hg ([95% CI, 8.8-15.2]; I²=81%) higher in FGR offspring. This difference was more pronounced in FGR males (13.6 mm Hg [95% CI, 10.3-17.0] versus 9.1 mm Hg [95% CI, 5.3-12.8]). Subgroup analyses on age showed no statistical interaction. BP readings under restrained conditions resulted in larger BP differences between FGR and control rats (15.3 mm Hg [95% CI, 11.6-18.9] versus 5.7 mm Hg [95% CI, 1.1-10.3]). Rat studies confirm the relation between FGR and offspring BP, while observational studies in humans do not show such differences. This may be due to the observational nature of human studies, methodological limitations, or an absence of this phenomenon in humans. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: CRD42018091819.

Impact of Birth Weight and Length on Primary Hypertension in Children

BACKGROUND

A child's birth parameters not only enable assessment of intrauterine growth but are also helpful in identifying children at risk of developmental defects or diseases occurring in adulthood. Studies show that children born with a body weight that is small for their gestational age (SGA) are at a greater risk of hypertension though the inverse relation between excessive birth weight and the risk of primary hypertension in children is discussed less frequently.

PURPOSE

To assess the impact of both birth weight and length on hypertension occurring in children aged 3-15 years.

METHODS

A total of 1000 children attending randomly selected primary schools and kindergartens were examined. Ultimately, the analyses took into account n = 747 children aged 4-15; 52.6% boys and 47.4% girls. The children's body height and weight were measured; their blood pressure was examined using the oscillometric method. Information on perinatal measurements was retrieved from the children's personal health records.

RESULTS

Compared to the children with small for gestational age (SGA) birth weight, the children with appropriate for gestational age birth weight (AGA) (odds ratio (OR) 1.31; 95% confidence interval (CI) 0.64-2.65) present greater risk for primary hypertension. Infants born with excessive body weight >4000 g irrespective of gestational age, compared to infants born with normal body weight, show increased risk of primary hypertension (OR 1.19; 95% CI 0.68-2.06). Higher risk of hypertension is observed in infants born with greater body length (OR 1.03; 95% CI 0.97-1.08).

CONCLUSIONS

The problem of hypertension may also affect children with birth weight appropriate for gestational age. The prevalence of hypertension in children with AGA birth weight decreases with age. Birth length can be a potential risk factor for hypertension in children and adolescents.

Complex lipid globules in early-life nutrition improve long-term metabolic phenotype in intra-uterine growth-restricted rats

Intra-uterine growth restriction (IUGR) is associated with adverse metabolic outcome later in life. Healthy mice challenged with a Western-style diet (WSD) accumulated less body fat when previously fed a diet containing large lipid globules (complex lipid matrix (CLM)). This study was designed to clarify whether an early-life CLM diet mitigates 'programmed' visceral adiposity and associated metabolic sequelae after IUGR. In rats, IUGR was induced either by bilateral uterine vessel ligation (LIG) or sham operation (i.e. intra-uterine stress) of the dam on gestational day 19. Offspring from non-operated (NOP) dams served as controls. Male offspring of all groups were either fed CLM or 'normal matrix' control diet (CTRL) from postnatal days (PND) 15 to 42. Thereafter, animals were challenged with a mild WSD until dissection (PND 98). Fat mass (micro computer-tomograph scan; weight of fat compartments), circulating metabolic markers and expression of 'metabolic' genes (quantitative real-time PCR) were assessed. CLM diet significantly reduced visceral fat mass in LIG at PND 40. At dissection, visceral fat mass, fasted blood glucose, TAG and leptin concentrations were significantly increased in LIG-CTRL v. NOP-CTRL, and significantly decreased in LIG-CLM v. LIG-CTRL. Gene expression levels of leptin (mesenteric fat) and insulin-like growth factor 1 (liver) were significantly reduced in LIG-CLM v. LIG-CTRL. In conclusion, early-life CLM diet mitigated the adverse metabolic phenotype after utero-placental insufficiency. The supramolecular structure of dietary lipids may be a novel aspect of nutrient quality that has to be considered in the context of primary prevention of obesity and metabolic disease in at-risk populations.