Vaginally-delivered Infants Research Articles

Impact of Postpartum Hospital Length-of-Stay on Infant Gut Microbiota: A Comprehensive Analysis of Vaginal and Caesarean birth

BackgroundThe primary concern with prolonged hospitalization following birth is the risk of acquiring hospital-acquired infections (HAIs) caused by opportunistic bacteria, which can alter the early establishment of gut microbiota. ObjectiveThis study aimed to assess the association between postpartum hospital length-of-stay (LOS) and the composition of gut microbiota at 3 and 12 months of age according to birth mode. MethodsA total of 1313 Canadian infants from the CHILD Cohort Study were involved in this study. Prolonged hospital LOS was defined as > 2 days following vaginal and > 3 days after caesarean section (CS) birth. Infants' gut microbiota was characterized by Illumina 16S rRNA sequencing of faecal samples at 3-4 months and 12 months. FindingsFollowing a prolonged hospital LOS, vaginally-delivered (VD) infants with no maternal intrapartum antibiotic (IAP) exposure had a higher abundance of bacteria in their gut known to cause HAIs, including Enterococcus at 3 and 12 months, Citrobacter at 3 months and C. difficile at 12 months. Enterococcus or Citrobacter abundance at 3 months significantly mediated the association between LOS, and low abundance of Bacteroidaceae, or higher Enterococcaeae/Bacteriodaceae or Enterobacteriaceae/Bacteroidaceae abundance ratios at 12 months of age in VD infants without IAP exposure. HAI-causing Enterobacteriaceae were also more abundant in later infancy with a longer hospital LOS following CS. In the absence of exclusive breastfeeding for 3 months or any breastfeeding at 12 months, the Porphyromonadaceae (of Bacteroidota) become depleted in CS infants with a prolonged LOS. ConclusionsProlonged hospital stay after birth is associated with infant gut dysbiosis.

Saccadic Latency Differences Between C-Section and Vaginally-Delivered Infants and Adults in a Visual Search Task

Saccadic Latency Differences Between C-Section and Vaginally-Delivered Infants and Adults in a Visual Search Task

Comparative analysis of thiol-disulfide homeostasis dynamics between elective cesarean section and uncomplicated vaginal delivery: insights into perinatal oxidative balance.

Thiols are organic compounds containing sulfhydryl groups that exert antioxidant effects via dynamic thiol-disulfide homeostasis. The shift towards disulfide indicates the presence of an oxidative environment. Different modes of delivery can affect thiol-disulfide homeostasis. Accordingly, we planned this research to evaluate the effects of the mode of delivery on thiol-disulfide homeostasis in both maternal serum and fetal cord blood samples. We conducted a prospective case-control study involving two groups: vaginal delivery (n=50) and elective cesarean section (CS) (n=45). The vaginal delivery group exclusively comprised uncomplicated term deliveries, while the CS group included pregnant individuals with scheduled cesarean deliveries due to the absence of spontaneous labor onset. Maternal serum and fetal cord blood samples were collected, and thiol-disulfide exchanges were analyzed using an automated method capable of measuring both aspects of the thiol-disulfide balance. The levels of native thiol (-SH) and total thiol in both maternal serum and fetal cord blood samples were significantly higher in the vaginal delivery group than those in the CS group. An important discovery of our study was that fetal cord disulfide (-SS) level, which may reflect oxidative stress, was higher in newborns born via vaginal delivery when examined alone. However, in both maternal and fetal cord blood, the combined ratios, SS/SH ratio (%), SS/Total thiol ratio (%), and SH/Total thiol ratio (%) were observed to be similar between the groups in both maternal and fetal cord blood. It was observed that as the mother's weight gained during pregnancy increased, SS/SH and SS/total thiol increased (positive correlation), while SH/total thiol decreased (negative correlation). Our results showed that the dynamic thiol-disulfide homeostasis was greatly influenced by the way of delivery and supported the idea that vaginally-delivered infants may have more oxidative stress.

Early Weight Loss Percentile Curves and Feeding Practices in Opioid-Exposed Infants.

We examined weight loss patterns and feeding practices of infants hospitalized for neonatal opioid withdrawal syndrome (NOWS) managed by the eat, sleep, console approach, which emphasizes nonpharmacologic treatment. Although feeding practices during hospitalization vary widely, weight loss patterns for infants managed under this approach have not yet been described. Of 744 infants with NOWS born from 2014 to 2019 at our institution, 330 met inclusion criteria (≥35 weeks' gestation and no NICU transfer). We examined maximum weight loss and created weight loss percentile curves by delivery type using mixed effects quantile modeling with spline effect for hour of life; 95% confidence intervals (CI) were compared to published early weight loss nomograms. In the cohort, the mean gestational age was 39.2 weeks, mean birth weight was 3.1 kg, and mean length of stay was 6.5 days; 94.6% did not require pharmacologic treatment. Median percent weight loss was significantly more compared to early weight loss nomograms for both vaginally-delivered infants at 48 hours (6.9% [95% CI: 5.8-8.5] vs 2.9%) and cesarean-delivered infants at 48 hours (6.5% [95% CI: 4.1-9.1] vs 3.7%) and 72 hours (7.2% [95%CI 4.7-9.9] vs 3.5%), all P < .001. Overall, 27.9% lost >10% birth weight. We demonstrate weight loss patterns of infants with NOWS managed by the eat, sleep, console approach at a single center. Infants with NOWS lose significantly more weight than nonopioid exposed infants and are at increased risk of morbidity and health care use. Studies to address optimal feeding methods in these infants are warranted.

Contribution of gut bacteria to arsenic metabolism in the first year of life in a prospective birth cohort

Gut bacteria are at the interface of environmental exposures and their impact on human systems, and may alter host absorption, metabolism, and excretion of toxic chemicals. We investigated whether arsenic-metabolizing bacterial gene pathways related to urinary arsenic concentrations. In the New Hampshire Birth Cohort Study, urine and stool samples were obtained at six weeks (n = 186) and one year (n = 190) of age. Inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and arsenobetaine (AsB) were quantified in infant urine samples using high-performance liquid chromatography with inductively coupled plasma mass spectrometry. Total arsenic exposure (tAs) was summarized as Σ(iAs, MMA, DMA) and log2-transformed. Fecal microbial DNA underwent metagenomic sequencing and the relative abundance of bacterial gene pathways were grouped as KEGG Orthologies (KOs) using BioBakery algorithms. Arsenic metabolism KOs with >80% prevalence were log2-transformed and modeled continuously using linear regression, those with <10% were not evaluated and those with 10–80% prevalence were analyzed dichotomously (detect/non-detect) using logistic regression. In the first set of models, tAs was regressed against KO relative abundance or detection adjusting for age at sample collection and child's sex. Effect modification by delivery mode was assessed in stratified models. In the second set of models, the association between the relative abundance/detection of the KOs and arsenic speciation (%iAs, %MMA, %DMA) was quantified with linear regression. Urinary tAs was associated with the increased relative abundance/detection odds of several arsenic-related KOs, including K16509, an arsenate reductase transcriptional regulator, with stronger associations among six-week-olds than one-year-olds. K16509 was also associated with decreased %MMA and increased %DMA at six weeks and one year. Notably, many associations were stronger among operatively-delivered than vaginally-delivered infants. Our findings suggest associations between arsenic-metabolizing bacteria in the infant gut microbiome and urinary arsenic excretion.

Abstract P034: The Association Of Breastfeeding With Lower Blood Pressure Is Stronger In Children Born Vaginally Compared To Cesarean Section

Introduction: A recent study of mother-child pairs in Canada (Miliku et al., JAHA 2021) found that ever (vs. never) breastfeeding was associated with lower blood pressure (BP) in early childhood. The authors posited the effect is modulated by the microbiome. However, they did not examine if the breastfeeding effect is stronger in vaginally-delivered infants, whom host more bacterial species (e.g., Bifidobacteria ) that bioconvert human milk oligosaccharides into BP-lowering butyrate. Given their population was majority White, it is unknown if breastfeeding lowers BP in non-White populations. Hypothesis: Introduction to breast milk in infancy lowers BP in childhood, particularly among vaginally delivered infants, in a racially diverse population. Methods: We used data from the Boston Birth Cohort. We assessed breastfeeding status during the postnatal follow up at &lt;2 years of age. Ever breastfeeding was defined as exclusively breastfed or a mix of breastfed and bottle-fed. We obtained repeated clinical measures of childhood systolic BP (SBP) across 0-17 years of age. We calculated age-, sex-, and height- specific child BP percentiles according to the 2017 American Academy of Pediatrics Clinical Practice Guidelines. We used linear regression with GEE with a link function and AR-1 correlation to examine the association of ever breastfeeding with child SBP. We controlled for maternal age, education, smoking, parity, pre-pregnancy BMI, hypertension, and child low birthweight, preterm birth, age, and sex. We assessed effect modification by race and delivery mode. Results: Our analytic sample comprised 19,597 BP measurements from 2,077 children, who were 52% male, 66% black, and had a mean age of 8 years. Among our sample, 33% were born preterm, 59% were vaginally delivered, and 74% were ever breastfed. Ever (vs. never) breastfeeding was associated with 1.74 percentile (95% CI: -3.66, 0.19; p=0.08) lower SBP. In children who were delivered vaginally, ever breastfeeding was associated with 2.63 percentile (95% CI: -5.12, -0.14; p=0.04) lower SBP. In contrast, among children delivered by Cesarean section, SBP percentile was not significantly reduced (95% CI: -3.45, 2.59; p=0.78) among ever breastfed. Moreover, ever breastfeeding was more strongly associated with lower BP among participants who self-identified as non-Black (3.40 percentile lower SBP; 95% CI: -6.30, -0.49; p=0.02) vs. Black (0.98 percentile lower SBP; 95% CI: -3.42, 1.45; p=0.43). Conclusion: In our racially diverse cohort, ever vs. never breastfeeding was associated with lower BP among children who were delivered vaginally, but not among those delivered by Cesarean section. The protective association of ever breastfeeding on child BP was also weaker in those born to mothers who self-identified as Black, highlighting the need for more research on the effects of breastfeeding on cardiometabolic health in racial minority groups.

Infant Feeding Alters the Longitudinal Impact of Birth Mode on the Development of the Gut Microbiota in the First Year of Life.

Cesarean-delivered (CD) infants harbor a distinct gut microbiome from vaginally delivered (VD) infants, however, during infancy, the most important driver of infant gut microbial colonization is infant feeding. Earlier studies have shown that breastfeeding is associated with higher levels of health-promoting bacteria such and Bifidobacterium and Bacteroides via modulation of the immune system, and production of metabolites. As the infant gut matures and solid foods are introduced, it is unclear whether longer duration of breast feeding restore loss of beneficial taxa within the intestinal microbiota of operatively delivered infants. Within the New Hampshire Birth Cohort Study, we evaluated the longitudinal effect of delivery mode and infant feeding on the taxonomic composition and functional capacity of developing gut microbiota in the First year of life. Microbiota of 500 stool samples collected between 6 weeks and 12 months of age (from 229 infants) were characterized by 16S ribosomal RNA sequencing. Shotgun metagenomic sequencing was also performed on 350 samples collected at either 6 weeks or 12 months of age. Among infant participants, 28% were cesarean-delivered (CD) infants and most (95%) initiated breastfeeding within the first six months of life, with 26% exclusively breastfed and 69% mixed-fed (breast milk and formula), in addition to complementary foods by age 1. Alpha (within-sample) diversity was significantly lower in CD infants compared to vaginally delivered (VD) infants (P < 0.05) throughout the study period. Bacterial community composition clustering by both delivery mode and feeding duration at 1 year of age revealed that CD infants who were breast fed for < 6 months were more dissimilar to VD infants than CD infants who breast fed for ≥ 6 months. We observed that breastfeeding modified the longitudinal impact of delivery mode on the taxonomic composition of the microbiota by 1 year of age, with an observed increase in abundance of Bacteroides fragilis and Lactobacillus with longer duration of breastfeeding among CD infants while there was an increase in Faecalibacterium for VD infants. Our findings confirm that duration of breastfeeding plays a critical role in restoring a health-promoting microbiome, call for further investigations regarding the association between breast milk exposure and health outcomes in early life.

Differences in Visual Search and Eye Movements Between Caesarean-Section and Vaginally-Delivered Infants and Adults

Differences in Visual Search and Eye Movements Between Caesarean-Section and Vaginally-Delivered Infants and Adults

Does birth mode modify associations of maternal pre-pregnancy BMI and gestational weight gain with the infant gut microbiome?

Background:Mother-to-newborn transmission of obesity-associated microbiota may be modified by delivery mode. Prospective data to test this hypothesis are still sparse.Objective:To examine prospective associations of maternal pre-pregnancy BMI and gestational weight gain with the infant gut microbiome by delivery-mode strata.Subjects/Methods:In 335 mother-infant pairs in the New Hampshire Birth Cohort, we ascertained data from questionnaires and medical records, and generated microbiome data from 6-week-old infants’ stool using Illumina 16S rRNA gene sequencing (V4-V5 region). Analyses were stratified by delivery mode and conducted before and after adjusting for potential confounders, which included maternal age, education, parity, and Mediterranean diet score.Results:Among 335 mothers, 56% had normal pre-pregnancy BMI (<25, referent), 27% were overweight (BMI 25.1–30), and 18% obese (BMI >30). Among the 312 mothers with weight gain data, 10% had inadequate weight gain, 30% adequate (referent), and 60% excess. In the vaginal-delivery group, maternal overweight or obesity was associated with higher infant gut microbiome diversity and higher abundance of 15 operational taxonomic units (OTUs), including overrepresentation of Bacteroides fragilis, Escherichia coli, Veillonella dispar and OTUs in the genera Staphylococcus and Enterococcus. Delivery mode modified associations of pre-pregnancy BMI with several genera, including the most abundant genus, Bacteroides (P for interaction = 0.05). In the Cesarean-delivered group, there were no significant associations between pre-pregnancy BMI, or gestational weight gain categories with infant microbiome (alpha) diversity or OTUs.Conclusions:Among vaginally-delivered infants, maternal overweight and obesity was associated with altered infant gut microbiome composition and higher diversity. These associations were not observed in Cesarean-delivered infants, whose microbiome development, we have shown, differs from vaginally-delivered infants. Our study provides additional evidence of delivery-mode dependent associations of maternal weight status with the infant gut microbiota. The role of these associations in mediating the intergenerational cycle of obesity warrants further examination.

Does cesarean delivery impact infant weight gain and adiposity over the first year of life?

Background:Potentially driven by the lack of mother-to-infant transmission of microbiota at birth, Cesarean delivery has been associated with higher offspring obesity. Yet, no studies have examined when delivery-mode differences in adiposity begin to emerge. In this study, we examine differences in infant weight and adiposity trajectories from birth to 12 months by delivery mode.Methods:From 2013 to 2015, we recruited pregnant women into the Nurture Study and followed up their 666 infants. We ascertained maternal delivery method and infant birth weight from medical records. We measured weight, length, and skinfolds (subscapular, triceps, abdominal) when infants were 3, 6, 9 and 12 months of age. The main outcome, infant weight-for-length z score, was derived based on the WHO Child Growth Standards. We used linear regression to assess the difference at each time point and used linear mixed models to examine the growth rate for infant weight and adiposity trajectories. We controlled for maternal age, race, marital status, education level, household income, smoking status, maternal pre-pregnancy body mass index, and infant birth weight.Results:Of the 563 infants in our final sample, 179 (31.8%) were Cesarean delivered. From birth to 12 months, the rate of increase in weight-for-length z score was 0.02 units/month (p=0.03) greater for Cesarean-delivered than vaginally-delivered infants. As a result of more rapid growth, Cesarean-delivered infants had higher weight-for-length z score (0.26 units, 95% CI 0.05–0.47) and sum of subscapular and triceps (SS+TR) skinfolds (0.95mm, 95% CI 0.30–1.60)—an adiposity indicator—at 12 months, compared to vaginally-delivered infants.Conclusion:Compared to vaginal delivery, Cesarean delivery was associated with greater offspring rate of weight gain over the first year and differences in adiposity that appear as early as 3 months of age. Monitoring Cesarean-delivered infants closely for excess weight gain may help guide primordial prevention of obesity later in life.

Prospects for primary prevention of type 1 diabetes by restoring a disappearing microbe

Prevention of childhood-onset type 1 diabetes has become more urgent with its marked increased incidence in recent decades in the modern world. Temporally associated with the rising incidence of type 1 diabetes, as well as other autoimmune and allergic diseases in childhood in modern times, is the disappearance of Bifidobacterium and specifically Bifidobacterium longum subsp. infantis (B. infantis) predominance in the intestinal microbiota of breastfed, vaginally-delivered infants. B. infantis efficiently metabolizes human milk oligosaccharides (HMOs) without cross-feeding free sugar monomers to other commensals or pathogens and thereby dominates the intestinal microbiota of breastfed infants. Increased levels of short-chain fatty acids (SCFA), which stimulate both immunoregulation and healthy intestinal and pancreatic β-cell function, are generated by B. infantis. Based on recent observations of the intestinal microbiota in early life in young children who develop type 1 diabetes and demonstration of the robust preventive effects of SCFA in animal models of autoimmune diabetes, we hypothesize that restoring a B. infantis-dominant microbiota early in infancy will prevent islet autoimmunity and childhood-onset type 1 diabetes.

The impacts of delivery mode on infant\u2019s oral microflora

This study investigated the effects of different delivery modes on oral microflora in healthy newborns immediately post-partum, and provided evidence for microbial colonization disruption induced by medical procedures. Eighteen infants delivered by cesarean section and 74 by vaginal delivery were included in the study. High-throughput sequencing of 16S bacterial rRNA was performed on oral samples collected immediately after birth. All data were analyzed using bioinformatics approaches. Our results indicated that different oral bacteria were found between infants delivered by cesarean section compared to vaginal delivery group. Lactobacillus, Prevotella and Gardnerella were the most abundant genera in the vaginal group, while Petrimonas, Bacteroides, Desulfovibrio, Pseudomonas, Staphylococcus, Tepidmicrobium, VadinCA02, and Bifidobacterium were dominant bacteria in the cesarean section (C-section) group. Furthermore, bacteria isolated from 27 vaginally-delivered infants were not clustered into the vaginal group. Most of them spent more than 24 hours in the delivery room and this led to repeated sterilization procedures. We hypothesized that repeated sterilization might have influenced oral microflora in those cases. To conclude, this study suggested that different modes of birth delivery affect oral microflora in healthy infants. In addition, attention shall be paid to the clinical practice of repeated sterilization of the vulva that possibly obstructs the colonization of vaginal bacterial.

Colonization and Succession within the Human Gut Microbiome by Archaea, Bacteria, and Microeukaryotes during the First Year of Life.

Perturbations to the colonization process of the human gastrointestinal tract have been suggested to result in adverse health effects later in life. Although much research has been performed on bacterial colonization and succession, much less is known about the other two domains of life, archaea, and eukaryotes. Here we describe colonization and succession by bacteria, archaea and microeukaryotes during the first year of life (samples collected around days 1, 3, 5, 28, 150, and 365) within the gastrointestinal tract of infants delivered either vaginally or by cesarean section and using a combination of quantitative real-time PCR as well as 16S and 18S rRNA gene amplicon sequencing. Sequences from organisms belonging to all three domains of life were detectable in all of the collected meconium samples. The microeukaryotic community composition fluctuated strongly over time and early diversification was delayed in infants receiving formula milk. Cesarean section-delivered (CSD) infants experienced a delay in colonization and succession, which was observed for all three domains of life. Shifts in prokaryotic succession in CSD infants compared to vaginally delivered (VD) infants were apparent as early as days 3 and 5, which were characterized by increased relative abundances of the genera Streptococcus and Staphylococcus, and a decrease in relative abundance for the genera Bifidobacterium and Bacteroides. Generally, a depletion in Bacteroidetes was detected as early as day 5 postpartum in CSD infants, causing a significantly increased Firmicutes/Bacteroidetes ratio between days 5 and 150 when compared to VD infants. Although the delivery mode appeared to have the strongest influence on differences between the infants, other factors such as a younger gestational age or maternal antibiotics intake likely contributed to the observed patterns as well. Our findings complement previous observations of a delay in colonization and succession of CSD infants, which affects not only bacteria but also archaea and microeukaryotes. This further highlights the need for resolving bacterial, archaeal, and microeukaryotic dynamics in future longitudinal studies of microbial colonization and succession within the neonatal gastrointestinal tract.

Partial restoration of the microbiota of cesarean-born infants via vaginal microbial transfer.

Exposure of newborns to the maternal vaginal microbiota is interrupted with cesarean birthing. Babies delivered by Cesarean section (C-section) acquire a microbiota that differs from that of vaginally delivered infants, and C-section delivery has been associated with increased risk for immune and metabolic disorders. Here we conducted a pilot study in which infants delivered by C-section are exposed to maternal vaginal fluids at birth. Similar to vaginally delivered babies, the gut, oral, and skin microbiome of these newborns during the first 30 days of life was enriched in vaginal bacteria underrepresented in unexposed C-section infants, albeit similarity to vaginally-delivered infants was higher in oral and skin than in anal samples. Although the long-term health consequences of restoring the microbiota of C-section born infants remain unclear, our results demonstrate that vaginal microbes can be partially restored at birth in C-section delivered babies.

External cephalic version after previous cesarean section—a clinical dilemma

OBJECTIVES: To describe our limited experience with external cephalic version from breech to vertex presentation at term, with the use of ritodrine tocolysis, in women who had undergone a previous cesarean delivery. METHODS: Eleven parturients after previous cesarean delivery underwent external version after 36 gestational weeks, utilizing tocolysis with ritodrine, after excluding cases of lowlying placenta, severe oligohydramnion or ruptured membranes. Patients were then followed until delivery and scar examination was carried out after vaginal delivery, or at re-cesarean section, according to mode of delivery. RESULTS: All 11 attempted versions were successful. Six patients subsequently delivered vaginally and five by re-cesarean section. None of the uterine scars showed any signs of dehiscence. Three of the five infants delivered by re-cesarean section weighed over 4000 g, whereas all of the vaginally-delivered infants weighed under 3500 g. CONCLUSIONS: External cephalic version to vertex presentation after previous cesarean section was successful in all 11 carefully selected patients. No untoward effects were noted, and no signs of scar dehiscence were found. The safety and efficacy of this procedure after previous cesarean delivery should be examined further.

Platelet ultrastructure of high-risk premature infants

Hemorrhagic and thrombotic complications are common in the term and preterm infant. Limited information is currently available about neonatal platelet structure and function, and how these may predispose infants to bleeding problems. This study comparing platelet ultrastructure of 71 different term and preterm infants with that of 15 adult control subjects revealed certain platelet morphological differences. Specifically, the adult platelets had more pseudopods, larger glycogen deposits, more visible microtubular structure, markedly fewer alpha granules, and smaller areas/ perimeters than the infant platelets. Also, in infants greater than 31 weeks gestation, the platelets of vaginally-delivered infants were larger than those of both infants delivered by C-section and normal adults. These differences in platelet size and morphology may be related to developmental differences and/or the stress of delivery. These findings provide a framework for further exploration of neonatal platelet structure and function.

Pregnancy at forty and over: a case-control study

We compared obstetric prognosis in 327 women ≥ 40 years old (148 nulliparas, 279 multiparas) with 20–30-year-old matched controls who delivered at our department between 1988 and 1990. Gestational diabetes and chronic hypertension were the only more frequent antepartum complications in cases than controls (2.4% vs. 0.3% and 3.4% vs. 0.3%, respectively). There were more premature deliveries in cases than controls (19% vs. 8%) but no difference in postdate deliveries. Cesarean section was more frequent in cases than controls in both nulliparas (64% vs. 30%) and multiparas (43% vs. 12%). Incidence of abdominal delivery for acute obstetrical indications was not increased in older gravidas. Significant differences were observed in low birthweight (17% vs. 5%) and 5-min Apgar score < 7 (8% vs. 2%). Most of the abnormal Apgar scores were recorded after cesarean section; values for vaginally-delivered infants were comparable in older and younger women. Perinatal mortality was similar in the two groups.

INFANT TEMPERAMENT ACCORDING TO RISK STATUS AND TYPE OF DELIVERY

The present study examined both parents' ratings of infant temperament according to the infant's risk status and type of delivery. Ninety parents rated their 45 infants, 23 of whom were low-risk and 22 who were high-risk with medical complications, on the Revised Infant Temperament Questionnaire (RITQ). Type of delivery was not related to the easy-difficult ratings of the high-risk babies; however, a strong trend (p<.067) emerged in the low-risk sample with C-section babies receiving more difficult ratings than the vaginally-delivered infants. As the easy-difficult ratings of the RITQ are determined by 5 individual profiles, these profiles were analyzed according to risk status and delivery type. The high-risk infants received more positive ratings on the mood profile than the low-risk infants (p<.04), while low-risk, C-section babies received the most negative ratings on mood (p<.04). Low-risk, C-section and high-risk, vaginally-delivered infants were rated more withdrawing than the low-risk, vaginally-delivered and high-risk, C-section babies (p<.001). In addition, there were trends for the high-risk babies to receive more rhythmic ratings than the low-risk infants (p<.06); vaginally-delivered infants were rated more adaptable than the C-section babies (p<.053); and low-risk, C-section babies were rated the least adaptable of all the infants (p<.07).