Pathological examination of the placenta in small for gestational age (SGA) children with or without postnatal catch-up growth

Growth trajectory of full-term small-for-gestational-age infants: a 3-year longitudinal study in China

OBJECTIVE

Small-for-gestational-age (SGA) infants are at risk of impaired growth and developmental outcomes, even for those who were born at full term. The growth trajectory of full-term SGA infants remains unknown. Therefore, this study aimed to evaluate the growth trajectory of full-term SGA infants from birth to 3 years old in East China.

METHODS

Full-term SGA infants were followed up from birth to 3 years old. The weight and length were measured at 3, 6, 12, 18, 24, 30 and 36 months. Rate of catch-up growth and rates of growth deviations including short stature, emaciation, underweight, overweight and obesity, were calculated at different time points. Latent class analysis was applied to describe growth trajectories from birth to 36 months.

RESULTS

A total of 816 full-term SGA infants were enrolled in this study and 303 had complete follow-up data at 3, 6, 12, 18, 24, 30 and 36 months. At 24 months, the rate of catch-up growth was 42.4% in girls and 48.6% in boys; while at 36 months, this rate was 43.3% in girls and 52.1% in boys. The latent class analysis identified two trajectories of weight and length in boys and girls. Girls showed different growth trajectories of weight since 12 months compared with boys.

CONCLUSIONS

Our study reported a relatively low rate of catch-up growth in full-term SGA infants and has identified different growth trajectories of length and weight in boys and girls. We call for attention from health professionals on the growth trajectory of full-term SGA infants to eventually promote their health potentials.

Prenatal exposure to per- and polyfluoroalkyl substances and pregnancy outcome in Austria

Per- and polyfluoroalkyl substances (PFAS) are a large group of persistent industrial chemicals that can harm reproductive health. PFAS levels were analysed to determine the current sources of exposure and possible associations between prenatal PFAS exposure and adverse pregnancy outcome. Samples from 136 mother-newborn pairs recruited between 2017 and 2019 were analysed for the presence of 31 target PFAS in maternal serum, umbilical cord serum, and placental tissue by high-performance liquid chromatography coupled to a tandem mass spectrometer. Questionnaires and medical records were used to survey sources of exposure and pregnancy outcome, including small for gestational age (SGA), fetal growth restriction (FGR), preeclampsia (PE), preterm birth, large for gestational age (LGA) and gestational diabetes mellitus (GDM). Data were analysed for individual PFAS and sum4PFAS (sum of perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) serum levels) in logistic regression analyses and categorical regression analyses. Compared to data from a previous Viennese study in 2010-12, sum4PFAS levels were generally lower. Sum4PFAS serum levels of three women (2.2%) exceeded 6.9 µg/L, a level that corresponds to the recently established tolerable weekly intake (TWI) of EFSA for nursing mothers aged 35 years; in the 2010/2012 study it was 13.6%. The large contribution of unidentified extractable organofluorine (EOF) fractions to total PFAS exposure is a concern. Study site, mean maternal corpuscular hemoglobin (MCH), use of facial lotion, and owning upholstered furniture were significantly influencing maternal exposure. While no effect of sum4PFAS on pregnancy outcome could be detected, we found highest placental PFDA levels in SGA births. PFHxS levels in umbilical cord and placenta were highest in preterm births. Further studies are needed to elucidate the relationship of prenatal PFAS exposure and pregnancy outcome, in particular to confirm whether and how placental PFDA levels may contribute to an increased risk for SGA.

Reduced Birth Weight and Exposure to Per- and Polyfluoroalkyl Substances: A Review of Possible Underlying Mechanisms Using the AOP-HelpFinder

Prenatal exposure to per- and polyfluorinated substances (PFAS) may impair fetal growth. Our knowledge of the underlying mechanisms is incomplete. We used the Adverse Outcome Pathway (AOP)-helpFinder tool to search PubMed for studies published until March 2021 that examined PFAS exposure in relation to birth weight, oxidative stress, hormones/hormone receptors, or growth signaling pathways. Of these 1880 articles, 106 experimental studies remained after abstract screening. One clear finding is that PFAS are associated with oxidative stress in in vivo animal studies and in vitro studies. It appears that PFAS-induced reactive-oxygen species (ROS) generation triggers increased peroxisome proliferator-activated receptor (PPAR)γ expression and activation of growth signaling pathways, leading to hyperdifferentiation of pre-adipocytes. Fewer proliferating pre-adipocytes result in lower adipose tissue weight and in this way may reduce birth weight. PFAS may also impair fetal growth through endocrine effects. Estrogenic effects have been noted in in vivo and in vitro studies. Overall, data suggest thyroid-damaging effects of PFAS affecting thyroid hormones, thyroid hormone gene expression, and histology that are associated in animal studies with decreased body and organ weight. The effects of PFAS on the complex relationships between oxidative stress, endocrine system function, adipogenesis, and fetal growth should be further explored.

Molecular Pathways of Cellular Senescence and Placental Aging in Late Fetal Growth Restriction and Stillbirth

Abnormally accelerated, premature placental senescence plays a crucial role in the genesis of pregnancy pathologies. Abnormal growth in the third trimester can present as small for gestational age fetuses or fetal growth restriction. One differs from the other by the presence of signs of placental insufficiency and the risk of stillbirth. The majority of stillbirths occur in normally grown fetuses and are classified as "unexplained", which often leads to conclusions that they were unpreventable. The main characteristic of aging is a gradual decline in the function of cells, tissues, and organs. These changes result in the accumulation of senescent cells in mitotic tissues. These cells begin the aging process that disrupts tissues' normal functions by affecting neighboring cells, degrading the extracellular matrix, and reducing tissues' regeneration capacity. Different degrees of abnormal placentation result in the severity of fetal growth restriction and its sequelae, including fetal death. This review aims to present the current knowledge and identify future research directions to understand better placental aging in late fetal growth restriction and unexplained stillbirth. We hypothesized that the final diagnosis of placental insufficiency can be made only using markers of placental senescence.

Gross and histological findings in the canine placenta and amnion at term: What's normal, abnormal or pathological?

The canine placenta is an underexamined organ. Placental abnormalities can affect foetus development and may be responsible for a low weight of the infant at birth; however, knowledge on their clinical significance in the canine species is limited. We aimed to describe macroscopic and microscopic findings in the canine placenta and amnion at term in clinically uncomplicated pregnancies and to evaluate their relationship with birth weight of healthy puppies. During natural delivery or C-section, the birth weight of 82 puppies was recorded, 72 placentas and 66 amnions were recovered. The foetal and maternal surfaces of the placental girdle, marginal haematoma and amnion were evaluated. Each gross finding was recorded, morphometrically assessed and sampled for histological diagnosis. Furthermore, specimens of placenta and amnion were collected from representative areas and microscopic deviations from normal structure were evaluated in haematoxylin and eosin sections. Gross examination revealed 'abnormalities' in the 75.4% of the collected placentas. Necrosis was the gross change most commonly observed in the placental girdle (72.5%). Congestion (17.4%) and clotted blood/fibrinoid material (2.9%) were also observed. No gross changes of either the marginal haematoma or the amnion were recorded. Histologically, placental girdle showed necrosis (62.3%), mineralization (52.2%), congestion (36.2%) and neutrophilic infiltration (27.5%). Marginal haematoma exhibited mineralization (11.6%) and neutrophils (29%), while necrotic foci were rarely observed (4.3%). In the amnion, the most frequent alteration observed was hypertrophy of the epithelium (35.9%) followed by oedema (31.2%), mineralized foci (28.1%), fibrosis (23.4%), congestion (15.6%) and more rarely neutrophils (12.5%). Puppies' birth weight was not statistically affected by either gross or histological abnormalities. Our study revealed that macroscopic and microscopic 'abnormalities' of the placenta and amnion may be common in uncomplicated pregnancies at term; however, no implications on puppies' birth weight were observed. Deviations from 'normal' morphology of canine foetal adnexa warrant further investigation to assess their clinical implications if present.

Antenatal and neonatal factors contributing to extra uterine growth failure (EUGR) among preterm infants in Boston Birth Cohort (BBC)

OBJECTIVE

Identify antenatal and neonatal factors associated with primary outcome of EUGR.

METHODS

1063 preterm infants from a subset of the BBC were included in this prospective cohort study. Regression analysis was carried out to evaluate associations of EUGR with antenatal factors and neonatal factors.

RESULTS

6.1% of the infants had in-utero growth restriction (IUGR) at birth and 21.7% of infants had EUGR. The adjusted odds ratio for EUGR status were significant for birth weight (OR 0.99, p = 0.00, CI 0.99-0.99), for GA at birth (OR 4.58, p = 0.00, CI 3.25-6.44), for PDA (OR 2.9, p = 0.02, CI 1.17-7.1), for NEC (OR 5.14, p = 0.012, CI 1.44-18.3) and for day of life of reaching full feeds (OR 1.04, p = 0.001, CI 1.01-1.06).

CONCLUSION

This study highlights important factors associated with EUGR. Additional studies are needed to gain further insight.