Clubfoot: Emphasis on the Complex and Atypical Subsets.

The Ponseti method has proven to be successful in the treatment of both isolated and non-isolated clubfoot. The method should be executed prior to any pediatric invasive procedures and likewise should be attempted with any pediatric recurrence. A thorough neurologic examination and attention to clinical signs will help distinguish the atypical clubfoot. Despite this approach some children do require return to serial casting, physical therapy, and or surgery to achieve a plantigrade functional foot. Bracing strategies at a time of growth remain key.

Fetal growth and pediatric cancer: A pan-cancer analysis in 7000 cases and 37 000 controls.

Birth weight is an established risk factor for some pediatric cancers but is dependent on gestational age and sex. Furthermore, it is unclear how associations may differ by infant sex, age at diagnosis, maternal race/ethnicity and maternal nativity status. We examined the association between size for gestation and a spectrum of pediatric cancers registered in the Texas Cancer Registry from 1995 to 2011. We analyzed up to 7547 cases and 37 735 controls. Analyses were conducted using logistic regression. Small-for-gestational age (SGA) and large-for-gestational age (LGA) were significantly associated with several tumors. SGA was associated with hepatic tumors (aOR = 1.76, 95% CI: 1.13, 2.74). Conversely, inverse associations were with Hodgkin lymphoma (aOR = 0.41, 95% CI: 0.19, 0.87) and soft tissue sarcomas (aOR = 0.65, 95% CI: 0.43, 0.97). LGA was associated with acute lymphoblastic leukemia (aOR = 1.37, 95% CI: 1.19, 1.57), Burkitt lymphoma (aOR = 1.90, 95% CI: 1.05, 3.45) and germ cell tumors (aOR = 1.55, 95% CI: 1.08, 2.23). Results did not differ when stratified by infant sex. The association with LGA and leukemia was strongest in those diagnosed 1 to 5 and 6 to 10 years. When stratified by maternal race/ethnicity, the association with LGA and neuroblastoma and renal tumors was strongest in children whose mother identified as non-Hispanic/Latina (H/L) Black. Among H/L women, children of Mexican-born women had a stronger association with LGA and leukemia, CNS tumors, neuroblastoma and renal tumors than children of US-born women (aOR range: 1.61-2.25 vs 1.12-1.27). Size for gestation is associated with several pediatric cancers. Associations may differ by age at diagnosis, maternal race/ethnicity and nativity.

Elucidating mechanisms linking mothers' and fathers' mind-mindedness in infancy with children's self-regulation at early preschool age.

Extensive research has examined factors that contribute to individual differences in children's self-regulation (SR), a key social-emotional competence crucial to adjustment and mental health. Those differences become salient and measurable at late toddler age. In the CAPS (N = 200 community families), we examined mothers' and fathers' appropriate mind-mindedness (MM)-the ability to view the child as a psychological agent and correctly interpret his or her mental states-as a predictor of children's SR. MM was observed in parent-child interactions at 8 months, and SR was observed as the capacity for deliberate delay in standard tasks at 3 years. Reflecting a family system perspective, processes both within and across mother-child and father-child relationships were examined in one model. Parent-child mutual responsiveness, observed during interactions at 16 months, was modeled as a mediator of the paths from MM to SR. Fathers' MM had a significant, direct positive effect on SR; in addition, it enhanced mutual responsiveness in both father-child and mother-child dyads and promoted child SR through enhanced mother-child mutual responsiveness. The findings elucidate relatively poorly understood mechanisms linking parental MM in infancy with SR at early preschool age, highlight similarities and differences in the processes unfolding in mother-child and father-child relationships, and emphasize interparental dynamics in socialization.

Reduced corticospinal drive to antagonist muscles of upper and lower limbs during hands-and-knees crawling in infants with cerebral palsy: Evidence from intermuscular EMG-EMG coherence.

BACKGROUND: There is growing interest in understanding the central control of hands-and-knees crawling, especially as a significant motor developmental milestone for early assessment of motor dysfunction in infants with cerebral palsy (CP) who have not yet acquired walking ability. In particular, CP is known to be associated with walking dysfunctions caused by early damage and incomplete maturation of the corticospinal tract. However, the extent of damage to the corticospinal connections during crawling in infants with CP has not been fully clarified. Therefore, this study aimed to investigate the disparities in intermuscular EMG-EMG coherence, which serve as indicators of corticospinal drives to antagonist muscles in the upper and lower limbs during crawling, between infants with and without CP. METHODS: This study involved 15 infants diagnosed with CP and 20 typically developing (TD) infants. Surface EMG recordings were obtained from two pairs of antagonist muscles in the upper limbs (triceps brachii (TB) and biceps brachii (BB)) and lower limbs (quadriceps femoris (QF) and hamstrings (HS)), while the infants performed hands-and-knees crawling at their self-selected velocity. Intermuscular EMG-EMG coherence was computed in two frequency bands, the beta band (15-30 Hz) and gamma band (30-60 Hz), which indicate corticospinal drive. Additionally, spatiotemporal parameters, including crawling velocity, cadence, duration, and the percentage of stance phase time, were calculated for comparison. Spearman rank correlations were conducted to assess the relationship between EMG-EMG coherence and crawling spatiotemporal parameters. RESULTS: Infants with CP exhibited significantly reduced crawling velocity, decreased cadence, longer cycle duration, and a higher percentage of stance phase time compared to TD infants. Furthermore, CP infants demonstrated decreased coherence in the beta and gamma frequency bands (indicators of corticospinal drive) in both upper and lower limb muscles. Regarding limb-related differences in the beta and gamma coherence, significant disparities were found between upper and lower limb muscles in TD infants (p < 0.05), but not in infants with CP (p > 0.05). Additionally, significant correlations between coherence metrics and crawling spatiotemporal parameters were identified in the TD group (p < 0.05), while such correlations were not evident in the CP group. CONCLUSIONS: Our findings suggest that the corticospinal drive may functionally influence the central control of antagonist muscles in the limbs during typical infant crawling. This functional role could be impaired by neurological conditions such as cerebral palsy. The neurophysiological markers of corticospinal drive, specifically intermuscular EMG-EMG coherence during crawling in infants with cerebral palsy, could potentially serve as a tool to assess developmental response to therapy.

Toddlers' affective responses to sociomoral scenes: Insights from physiological measures.

A growing literature suggests that preverbal infants are sensitive to sociomoral scenes and prefer prosocial agents over antisocial agents. It remains unclear, however, whether and how emotional processes are implicated in infants' responses to prosocial/antisocial actions. Although a recent study found that infants and toddlers showed more positive facial expressions after viewing helping (vs. hindering) events, these findings were based on naïve coder ratings of facial activity; furthermore, effect sizes were small. The current studies examined 18- and 24-month-old toddlers' real-time reactivity to helping and hindering interactions using three physiological measures of emotion-related processes. At 18 months, activity in facial musculature involved in smiling/frowning was explored via facial electromyography (EMG). At 24 months, stress (sweat) was explored via electrodermal activity (EDA). At both ages, arousal was explored via pupillometry. Behaviorally, infants showed no preferences for the helper over the hinderer across age groups. EMG analyses revealed that 18-month-olds showed higher corrugator activity (more frowning) during hindering (vs. helping) actions, followed by lower corrugator activity (less frowning) after hindering (vs. helping) actions finished. These findings suggest that antisocial actions elicited negativity, perhaps followed by brief disengagement. EDA analyses revealed no significant event-related differences. Pupillometry analyses revealed that both 18- and 24-month-olds' pupils were smaller after viewing hindering (vs. helping), replicating recent evidence with 5-month-olds and suggesting that toddlers also show less arousal following hindering than following helping. Together, these results provide new evidence with respect to whether and how arousal/affective processes are involved when infants process sociomoral scenarios.

Intuitive mapping between nonsymbolic quantity and observed action across development.

Adults' concurrent processing of numerical and action information yields bidirectional interference effects consistent with a cognitive link between these two systems of representation. This link is in place early in life: infants create expectations of congruency across numerical and action-related stimuli (i.e., a small [large] hand aperture associated with a smaller [larger] numerosity). Although these studies point to a developmental continuity of this mapping, little is known about the later development and thus how experience shapes such relationships. We explored how number-action intuitions develop across early and later childhood using the same methodology as in adults. We asked 3-, 6-, and 8-year-old children, as well as adults, to relate the magnitude of an observed action (a static hand shape, open vs. closed, in Experiment 1; a dynamic hand movement, opening vs. closing, in Experiment 2) to either a small or large nonsymbolic quantity (numerosity in Experiment 1 and numerosity and/or object size in Experiment 2). From 6 years of age, children started performing in a systematic congruent way in some conditions, but only 8-year-olds (added in Experiment 2) and adults performed reliably above chance in this task. We provide initial evidence that early intuitions guiding infants' mapping between magnitude across nonsymbolic number and observed action are used in an explicit way only from late childhood, with a mapping between action and size possibly being the most intuitive. An initial coarse mapping between number and action is likely modulated with extensive experience with grasping and related actions directed to both arrays and individual objects.

Motor constraints on infant search: The impact of reaching around a barrier on search performance.

This study investigated the impact of perceptual-motor context on a classic paradigm used to assess cognitive-spatial reasoning. Specifically, this project explored the effect on search behavior of reaching around a barrier versus not reaching around a barrier during the A portion in the B phase of the well-known A-not-B task. In examining 8- and 16-month-old infants, this study found that both age groups demonstrated poorer performance on A trials when needing to reach around a barrier than when there was no barrier present. More interestingly, for the younger infants, needing to reach around a barrier on A trials led to better performance on B trials relative to infants who did not reach around a barrier. Older infants, however, showed no difference in B trial performance. These results demonstrate that inducing constraints on reaching (e.g., reaching around a barrier) has a significant impact on search behavior, a finding that theoretically fits with a literature demonstrating a fundamental role in behavior of perceptual and motor influences in A-not-B behavior.

Gastric clot formation and digestion of milk proteins in static in vitro infant gastric digestion models representing different ages.

Gastric digestion conditions change during infancy from newborn towards more adult digestion conditions, which can change gastric digestion kinetics. However, how these changes in gastric digestion conditions during infancy affect milk protein digestion has not been investigated. Therefore, we aimed to investigate milk protein digestion with static in vitro gastric digestion models representing one-, three- and six-month-old infants. With increasing age, gastric clots and soluble proteins were digested more extensively, which may partly be attributed to the looser gastric clot structure. Larger differences with increasing age were found for heated than unheated milk proteins, which might be caused by the presence of denatured whey proteins. Taken together, these findings show that gastric milk protein digestion increases during infancy. These in vitro gastric digestion models could be used to study how milk protein digestion changes with infant age, which may aid in developing infant formulas for different age stages.

A comprehensive evaluation of milk protein molecular weight distribution based on exclusion chromatography dataset.

Molecular weight is one of the main characteristic parameters of proteins, which is the basis for the functional properties of milk protein. This research aims at establishing molecular weight distribution pattern of milk protein based on exclusion chromatography. The method selected Na3PO4-Na2SO4 (0.1 M, pH 6.7) buffer as the mobile phase and detected at 220 nm by HPLC-UV. The protein molecular weight distributions were determined and compared for human milk, bovine milk, and infant formula. The proportion of macromolecular proteins is much higher in infant formula compared to human or bovine milk. The protein molecular weights of human and bovine milk are significantly different around 90, 20, 14, and 2 kDa. The results provide holistic compare of bovine milk, human milk, and infant formula through protein molecular distribution. The new evaluation indicators for protein will drive technological simulation of infant formula.

Steam disinfection enhances bioaccessibility of metallic nanoparticles in nano-enabled silicone-rubber baby bottle teats, pacifiers, and teethers.

Nano-enabled silicone-rubber articles for feeding or chewing could be a source of metallic nanoparticles (NPs) directly exposed to infants and young children. However, the impact of steam disinfection on release of NPs and the related potential risks to children's health are unknown. Here, we investigated contents and form of Ag and Zn in 57 nano-enabled silicone-rubber baby bottle teats, pacifiers, and teethers of seven countries and examined the impacts of steam disinfection on in vitro bioaccessibility (IVBA) of Ag and Zn in the articles. Nearly 89% articles had a mixture of Ag- and Zn-containing NPs and the teethers had relatively high Ag and Zn contents (up to 501 and 254 µg/g, respectively). Steam disinfection caused rubber decomposition into micro(nano)plastics (0.54-15.7 µm) and NP release from the interior of bulk rubber and micro-sized plastics, thus enhancing the IVBA of Ag and Zn by up to 5.5 times. The findings provide insights into mechanisms for NP release by steam disinfection. Though oral exposure risk assessment suggested low health concerns on individual metal release, our study points out the need to assess the potential health risks of child co-exposure to metallic NPs and micro(nano)plastics.

Maternal anxiety during pregnancy predicts infant attention to affective faces.

BACKGROUND: Prenatal maternal anxiety is a known influence on offspring development. General anxiety and pregnancy-related anxiety (a distinct type of anxiety encompassing fears associated with pregnancy) are associated with offspring socioemotional development, with potential consequences for later emotional and behavioral problems. This study examines whether maternal pregnancy-related and general anxiety relate to infant attention to affective faces, a process which plays an integral role in early socioemotional development. METHODS: Participants included 86 mothers and their 6-month-old infants (56.3 % female). Mothers completed measures of pregnancy-related and general anxiety three times through gestation. Infants' attention to affective faces was assessed with an eye-tracking task during which a series of face pairs were presented (happy, angry, or sad face paired with a neutral face). Overall attention measures included attention-holding (total looking time) and attention-orienting (latency to faces); affect-biased attention measures included proportion of total looking time to emotional faces and latency difference score. RESULTS: Higher maternal pregnancy-related anxiety across gestation predicted decreased infant attention-holding to affective faces [F(1,80) = 7.232, p = .009, partial η2 = 0.083]. No differences were found in infant attention-orienting or affect-biased attention. LIMITATIONS: Reliance on a correlational study design precludes the ability to make causal inferences. CONCLUSIONS: Maternal pregnancy-related anxiety is an important predictor of child outcomes. We provide novel evidence that pregnancy-related anxiety predicts infant attention to emotional faces, behaviors which have important implications for socioemotional development. Providers may consider pregnancy-related anxiety as a target for screening and treatment that may benefit both pregnant individual and offspring.

Effect of ferric ions on Cronobacter sakazakii growth, biofilm formation, and swarming motility.

Cronobacter sakazakii (C. sakazakii) is a common food-borne pathogen that induces meningitis, sepsis, and necrotizing enterocolitis, primarily in newborns and infants. Iron plays a pivotal role in the growth of cells and biofilm formation. However, the effects of hemin (ferric ion donor) on C. sakazakii cells are scarcely known. Here, we explored the effect of ferric ions on the growth of planktonic C. sakazakii, biofilm formation, and swarming motility by crystal violet staining (CVS), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and swarming assay. Our study demonstrated that ferric ions facilitated the growth of planktonic C. sakazakii, while hemin at concentrations ranging from 50 to 800 µmol/L promoted biofilm formation and at concentrations between 50 and 200 µmol/L enhanced the swarming motility of C. sakazakii. Furthermore, high hemin concentrations (400-800 µmol/L) were found to reduce flagellar length, as confirmed by transmission electron microscopy (TEM). These findings indicated that ferric ions mediated the swarming motility of C. sakazakii by regulating flagellar assembly. Finally, transcriptomic analysis of C. sakazakii was performed at hemin concentrations of 0, 50, and 200 µmol/L, which revealed that several genes associated with iron transport and metabolism, and flagellar assembly were essential for the survival of C. sakazakii under hemin treatment. Our findings revealed the molecular basis of ferric ions on C. sakazakii growth and biofilm formation, thus providing a novel perspective for its prevention and control.

Emotional response in babies' pupil contagion.

In this study, it was investigated whether an emotional response would occur in pupil contagion by using skin conductance response (SCR) in 5- and 6-month-old infants. In the experiment, emotional responses to pupil diameter change (dilating/constricting) between the face and eyes regions were compared by using pupil diameter response and SCR. The results showed that pupil diameter responses to pupil diameter changes did not differ between face and eyes regions. The emotional response indicated by the SCR significantly increased when participants looked at dilating pupils of face stimuli compared with when participants looked at constricted pupils of face stimuli. In addition, we found a significant correlation between SCR and pupil dilation in the face. This means that pupil diameter expansion significantly increases emotional response in pupil dilation of the face region.

Controlling posture to see the world: The integration of visual task demands and postural sway in sitting and standing infants.

Our ability to integrate posture with visually demanding tasks is a critical aspect of motor behavior flexibility. When looking at a small object, excessive body movements impair an individual's ability to visually attend to the object. To overcome this problem, we adjust our postural sway to successfully focus on the object. The goal of the current study was to assess whether infants also adjust postural sway when engaged in a challenging visual task. The participants, 19 independently sitting infants (Sitters) and 21 newly independently standing infants (Standers), sat or stood on a force plate while viewing differently sized images displayed on a monitor (smaller images: 8 × 6.5 cm or 3 × 3 cm; larger images: 13 × 16 cm or 13 × 13 cm). Regardless of image size, Standers were less stable than Sitters with larger sway areas and faster sway velocities. Both Sitters and Standers adjusted sway area but not sway velocity, based on image size. Sitters and Standers differed in how they controlled sway dynamics. Standers but not Sitters altered sway dynamics based on image size. Overall, infants used posture-specific adaptive control strategies to make fine-grained adjustments based on image size. The development of the ability to integrate posture with a visually demanding task further emphasizes the capability of advanced complex motor behaviors during infancy, enabling infants to flexibly attend to important aspects of their environment at different postural positions.

Diabetes ketoacidosis and Recurrent Childhood Stroke-like Episodes.

A 13-year and 4-month-old girl was brought to the emergency department due to fever, dizziness,vomiting, and blurred vision. Laboratory data revealed hyperglycemia with an HbA1C of 7.3 percent, ketonuria, and lactic acidosis. The initial impression was diabetic ketoacidosis. During admission, recurrent focal impaired awareness seizures were noted, and magnetic resonance imaging of the brain revealed multiple brain infarctions in the bilateral cerebrum. Mitochondrial gene report showed A3243 G with 64 percent heteroplasmy, and mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes was diagnosed. At 16 years and 7 months old, recurrence of vomiting and onset of right hemianopia and mild right limb weakness were observed and follow-up T2 images showed massive edema in her left parieto-occipital region. At 16 years and 10 months old, she developed clonus in her left hand associated with an unsteady gait and blurred vision. MRI of the brain revealed recurrent brain infarction, and T2 images showed massive edema of the right parieto-occipital region. MELAS is a rare disease entity and occasionally comorbid with mitochondrial diabetes in childhood. Characteristic radiological features of MELAS include infarction-like lesions over the parieto-occipital or parieto-temporal areas, which help distinguish MELAS from childhood ischemic stroke.

CpxAR two-component system contributes to virulence properties of Cronobacter sakazakii.

Cronobacter sakazakii (C. sakazakii) is a foodborne pathogen which threaten susceptible hosts including infants. CpxA/CpxR, a regulatory two-component system (TSC), contributes to stress response and virulence in various Gram-negative pathogens, but its role in C. sakazakii has not been thoroughly studied. In this study, we constructed CpxA, CpxR, CpxAR deletion and complementation strains. The mutants showed weakened bacterial adhesion to and invasion of HBMEC and Caco-2, reduced intracellular survival and replication of C. sakazakii within RAW264.7 macrophages, and decreased translocation of HBMEC and Caco-2 monolayers. Mutants demonstrated lower levels of tight junction proteins disruption and reduced apoptosis and cytotoxicity in Caco-2 monolayer compared to wild type strain. CpxAR TCS deletion mutants demonstrate attenuated virulence in newborn mice, which was evidenced by fewer bacterial cells loads in tissues and organs, lower levels of intestinal epithelial barrier dysfuction and milder damages in intestinal tissues. All these phenotypes were recovered in complemented strains. In addition, qRT-PCR results showed that CpxAR TCS of C. sakazakii played roles in regulating the expression of several genes associated with bacterial virulence and cellular invasion. These findings indicate that CpxAR TCS is an important regulatory mechanism for virulence of C. sakazakii, which enrich our understanding of genetic determinants of pathogenicity of the pathogen.

Prenatal Measurements of Congenital Lung Malformations: Can They Predict Postnatal Size?

INTRODUCTION: Prenatally diagnosed congenital lung malformations (CLMs) are monitored via ultrasound and measured by congenital pulmonary airway malformation volume ratios (CVRs) which can predict postnatal respiratory symptoms. This study compared CVR to postnatal lesion size to help guide prenatal counseling. METHODS: A retrospective chart review evaluated the prenatal imaging and postnatal outcomes for patients who were prenatally diagnosed with CLMs and had a postnatal computed tomography (CT) scan at one institution. RESULTS: Fifty-seven patients were included. Four had symptoms requiring urgent resection. The remaining were discharged and had clinic follow-up with CT scan to determine next steps: five had no identified lesions, eight had lesions whose diagnosis did not warrant an operation, and 40 had lesions whose diagnosis rendered size a factor in operative decision-making. Of these 40, 26/40 patients (65%) underwent elective resection (median maximum CVR 0.97; median lesion size 4 cm) and 14/40 patients (35%) were observed without resection (median maximum CVR 0.5; median lesion size 3 cm). There was a positive correlation between prenatal CVR and postnatal lesion size, with R-squared = 0.46. Maximum CVRs were better than last CVRs when predicting whether postnatal CT size would fall above or below our institution's level of recommended resection, with an area under the curve of 0.85 and a CVR cut-point of 0.61. CONCLUSIONS: For newborns with asymptomatic CLMs, higher maximum CVRs correlated with larger size on postnatal CT. A maximum CVR ≤0.6 was correlated with a smaller postnatal CT size that may be eligible for nonoperative management. While these results are not intended to recommend surgery based on higher CVRs alone, this information could potentially be used to reassure expectant parents whose babies' prenatal imaging demonstrate lower maximum CVRs.

Nonsyndromic Craniofacial Disorders.

We describe the investigation and management of select pediatric craniofacial disorders their recent advances. Positional plagiocephaly: The incidence of positional plagiocephaly has increased since the institution of the "safe to sleep" campaign to reduce sudden infant death syndrome. Positional plagiocephaly may be associated with underlying developmental delay. Nonsyndromic craniosynostosis: Treatment of nonsyndromic craniosynostosis depends on the age of the patient and the suture involved. Pediatric skull lesions: Management of skull lesions depends on histologic diagnosis. Some benign skull lesions are managed conservatively, whereas erosive and malignant lesions may require surgical excision, radiotherapy, chemotherapy, or multimodality treatment.

Role of inflammatory lipid and fatty acid metabolic abnormalities induced by plastic additives exposure in childhood asthma.

Lipid metabolism play an essential role in occurrence and development of asthma, and it can be disturbed by phthalate esters (PAEs) and organophosphate flame retardants (OPFRs). As a chronic inflammatory respiratory disease, the occurrence risk of childhood asthma is increased by PAEs and OPFRs exposure, but it remains not entirely clear how PAEs and OPFRs contribute the onset and progress of the disease. We have profiled the serum levels of PAEs and OPFRs congeners by liquid chromatography coupled with mass spectrometry, and its relationships with the dysregulation of lipid metabolism in asthmatic, bronchitic (acute inflammation) and healthy (non-inflammation) children. Eight PAEs and nine OPFRs congeners were found in the serum of children (1 - 5 years old) from Shenzhen, and their total median levels were 615.16 ng/mL and 17.06 ng/mL, respectively. Moreover, the serum levels of mono-methyl phthalate (MMP), tri-propyl phosphate (TPP) and tri-n-butyl phosphate (TNBP) were significant higher in asthmatic children than in healthy and bronchitic children as control. Thirty-one characteristic lipids and fatty acids of asthma were screened by machine-learning random forest model based on serum lipidome data, and the alterations of inflammatory characteristic lipids and fatty acids including palmitic acids, 12,13-DiHODE, 14,21-DiHDHA, prostaglandin D2 and LysoPA(18:2) showed significant correlated with high serum levels of MMP, TPP and TNBP. These results imply PAEs and OPFRs promote the occurrence of childhood asthma via disrupting inflammatory lipid and fatty acid metabolism, and provide a novel sight for better understanding the effects of plastic additives on childhood asthma.

Prenatal exposure to per- and polyfluoroalkyl substances and DNA methylation in the placenta: A prospective cohort study.

Epidemiological studies regarding the relationship between per- and polyfluoroalkyl substances (PFAS) and DNA methylation were limited. We investigated the associations of maternal PFAS concentrations with placental DNA methylation and examined the mediating role of methylation changes between PFAS and infant development. We measured the concentrations of 11 PFAS in maternal plasma during early pregnancy and infant development at six months of age. We analyzed genome-wide DNA methylation in 16 placental samples using reduced representation bisulfite sequencing. Additionally, we measured DNA methylation levels using bisulfite amplicon sequencing in 345 mother-infant pairs for five candidate genes, including carbohydrate sulfotransferase 7 (CHST7), fibroblast growth factor 13 (FGF13), insulin receptor substrate 4 (IRS4), paired like homeobox 2Ap (PHOX2A), and plexin domain containing 1 (PLXDC1). We found that placental DNA methylation profiles related to PFOA mainly enriched in angiogenesis and neuronal signaling pathways. PFOA was associated with hypomethylation of IRS4 and PLXDC1, and PFNA was associated with PLXDC1 hypomethylation. There were positive associations of CHST7 methylation with PFTrDA and IRS4 methylation with PFDoA and PFTrDA. PLXDC1 hypomethylation mediated the association between PFOA and suspected developmental delay in infants. Future studies with larger sample sizes are warranted to confirm these findings.