Fetal cortisol in relation to labour, intrapartum events and mode of delivery

Obesity in pregnancy-Long-term effects on offspring hypothalamic-pituitary-adrenal axis and associations with placental cortisol metabolism: A systematic review

Obesity, affecting one in three pregnant women worldwide, is not only a major obstetric risk factor. The resulting low-grade inflammation may have a long-term impact on the offspring's HPA axis through dysregulation of maternal, placental and fetal corticosteroid metabolism, and children born of obese mothers have increased risk of diabetes and cardiovascular disease. The long-term effects of maternal obesity on offspring neurodevelopment are, however, undetermined and could depend on the specific effects on placental and fetal cortisol metabolism. This systematic review evaluates how maternal obesity affects placental cortisol metabolism and the offspring's HPA axis. Pubmed, Embase and Scopus were searched for original studies on maternal BMI, obesity, and cortisol metabolism and transfer. Fifteen studies were included after the screening of 4556 identified records. Studies were small with heterogeneous exposures and outcomes. Two studies found that maternal obesity reduced placental HSD11β2 activity. In one study, umbilical cord blood cortisol levels were affected by maternal BMI. In three studies, an altered cortisol response was consistently seen among offspring in childhood (n = 2) or adulthood (n = 1). Maternal BMI was not associated with placental HSD11β1 or HSD11β2 mRNA expression, or placental HSD11β2 methylation. In conclusion, high maternal BMI is associated with reduced placental HSD11β2 activity and a dampened cortisol level among offspring, but the data is sparse. Further investigations are needed to clarify whether the HPA axis is affected by prenatal factors including maternal obesity and investigate if adverse effects can be ameliorated by optimising the intrauterine environment.

The association between a single abnormal glucose and fetal c-peptide

AIM

We aimed to evaluated if fetuses of subjects with one elevated value on the 3-h GTT had a measurable physiologic difference in fetal C-peptide levels as compared to those with no elevated values on the GTT.

METHODS

We performed a prospective cohort study to evaluate insulin levels in singleton non-anomalous fetuses of subjects with one elevated value on the GTT as compared to subjects with no elevated values on their GTT. Fetal insulin levels were measured by fetal C-peptide in cord blood. Distribution of data was assessed and outliers representing values > the 99th and < the 1st percentiles were excluded. Data were log transformed to achieve normal distribution and univariable analyses were performed to compare fetal C-peptide levels, baseline maternal characteristics and perinatal outcomes in subjects with one elevated value as compared those with no elevated values.

RESULTS

Our analysis included 99 subjects, with 49 subjects in the one elevated value group and 50 subjects in the no elevated values group. Fetal C-peptide levels (picomoles per liters, pmol/L), were significantly higher in the elevated value group as compared to the no elevated value group (mean ± SD; 4.6 ± 0.8 vs. 4.3 ± 0.7, P = 0.046, respectively). In univariable analysis, there was no significant difference in maternal characteristics or adverse composite perinatal outcomes.

CONCLUSION

Fetuses of subjects who had one elevated value on their GTT had a measurable physiologic difference in C-peptide levels as compared to fetuses of subjects with no elevated values on the GTT.

The Interplay of Cesarean-Section Delivery and First-Birth Order as Risk Factors in Acute Lymphoblastic Leukemia

BACKGROUND

Childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) has been associated with early-life exposures, including birth by cesarean section (C-section), and a deficit of social exposure (first child). These exposures as proxies for microbiome acquisition in infancy are essential to prime the immune system and restrain later dysregulated immune responses that can trigger ALL in susceptible individuals. We tested risk factors pertaining to immune stimulation that may impact BCP-ALL development.

METHODS

Cases comprised 1,126 children (0-12 years) with ALL (BCP-ALL: 78.5%) from the EMiLI study group in Brazil (2002-2020). Age- and sex-matched controls (n = 2,252) were randomly selected from healthy children whose mothers participated in the National Placental and Umbilical Cord Blood Bank donation. Multiple logistic regression was run fitted and adjusted for selected covariates models.

RESULTS

C-section delivery was associated with increased risk for ALL [odds ratio (OR) ALL: 1.10; 95% confidence intervals (CI), 1.04-1.15; ORBCP-ALL: 1.09; 95% CI, 1.03-1.14], as well as being the firstborn child. Interaction analysis showed a significant effect of first birth on the observed C-section associations (P < 0.0001). Indeed, high-risk children, namely, firstborn children delivered via C-section were at increased risk for ALL (OR: 2.33; 95% CI, 2.40-4.84) compared with non-first, vaginally born children. An increased risk was found for firstborn children delivered by C-section and non-breastfed with ALL (ORALL: 2.32; 95% CI, 1.27-4.24; ORBCP-ALL: 2.37; 95% CI, 1.18-4.76).

CONCLUSIONS

Our observations are in accord with the prediction that exposures determining microbiome composition and adrenal pathway in infancy contribute to the risk of BCP-ALL.

IMPACT

These findings encourage the exploration of potential preventive interventions. See related commentary by Wiemels and Gallant, p. 292.

Association of cesarean section with risk of childhood leukemia: A meta-analysis from an observational study

Recent studies suggest that children born via cesarean section (CS) are predisposed to immune-mediated diseases later in life. The association between CS and childhood leukemia was investigated in this meta-analysis of observational studies. Two researchers independently searched PubMed, Web of Science, Embase, and Cochrane Library for literature on the association between CS and childhood leukemia before February 2022. And pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated to determine the link between CS and childhood leukemia. The preliminary search resulted in 1321 articles and 16 articles were finally included after screening. The primary outcome was the risk of leukemia in children born via CS versus those born vaginally. The results revealed that having a CS was associated with an increased risk of childhood leukemia compared to having vaginal section (VS) (OR = 1.07, 95% CI: 1.02-1.13, p = 0.01), especially for acute lymphoblastic leukemia (ALL) (OR = 1.09, 95% CI: 1.03-1.16, p = 0.004). Children delivered via elective CS had a higher risk of ALL (OR = 1.18, 95% CI: 1.07-1.31, p = 0.001), but emergency CS did not. It is worth noting that neither emergency CS nor elective CS were found to be associated with acute myeloid leukemia. Compared to VS, CS increased the risk of leukemia in children, with elective CS significantly increasing ALL risk.

Association between obstetric mode of delivery and emotional and behavioural problems in children and adolescents: the children of the 90s health study

PURPOSE

Existing evidence on the relationship between mode of delivery and offspring emotional and behavioural problems, especially in older age groups, is limited and inconsistent. This study aimed to examine the association between obstetric mode of delivery and emotional and behavioural problems in offspring aged 3-16 years.

METHODS

The sample for this study comprised participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) in the United Kingdom. The study cohort ranged from 7074 (at 3 years of age) to 4071 (at 16 years of age) mother-offspring pairs. Data on obstetric mode of delivery were abstracted from obstetric records by trained research midwives and classified as spontaneous vaginal delivery, assisted vaginal delivery and caesarean delivery (elective and emergency). Offspring emotional and behavioural problems were measured using the Strengths and Difficulties Questionnaire (SDQ) when the child was 3, 7, 9, 11, and 16 years. Logistic regression analyses were used to examine associations.

RESULTS

Assisted vaginal delivery was associated with an increased risk of emotional problems at age 11 years (OR = 1.42; 95% CI 1.11-1.81). No significant associations were observed at ages 3, 7, 9 and 16. We found no evidence of associations between caesarean delivery (elective or emergency) and emotional and behavioural measures in offspring across all age groups.

CONCLUSION

Mode of delivery does not appear to be associated with emotional and behavioural problems in children and adolescents. Further research is needed to understand the potential longer-term effects of assisted vaginal deliveries on offspring emotional development.

Can maternal hormones play a significant role in delivery mode?

The aim of this study was primarily to evaluate the levels of progesterone, oestradiol and relaxin during different delivery modes and secondarily to assess specific traits and changes in maternal pelvic dimensions during pregnancy and childbirth, in correlation with foetal size and maternal hormonal profile. Nulliparous women (n = 448) were evaluated at three different stages, during first trimester, at the time of admission for childbirth and finally just before childbirth. Each examination included clinical internal pelvimetry, blood sample collection for defining the hormones levels in peripheral maternal circulation and ultrasonographic measurements of specific variables of the pubic symphysis and the foetus. We included 304 nulliparous women divided in three groups. According to our results, there was statistically significant difference at the mean progesterone, oestradiol and relaxin range during different modes of childbirth (p-value < .01). We also found significant correlation between the newborn's weight and the changes in pubic symphysis dimensions. However, no significant association was noted between maternal hormones studied and the changes in pelvic dimensions.IMPACT STATEMENTWhat is already known on this subject? Mode of childbirth can be affected by various aspects, like maternal pelvic anatomy, foetal size and hormonal status at the time of labour. Hormonal fluctuations along with mechanical forces caused by the foetus are believed to lead to morphological alterations to promote natural vaginal childbirth.What do the results of this study add? Our results clearly showed that successful vaginal delivery is characterised by the prevalence of a hyperoestrogenic environment with higher values of intrapartum oestradiol range and significant increase in maternal serum relaxin levels. We also proved that progesterone levels do not decrease during vaginal childbirth, and we concluded that foetal size seems to be the most crucial factor causing alterations in maternal pelvis during parturition.What are the implications of these findings for clinical practice and further research? Our findings could form part of a set of key factors included in future algorithms or computerised biomechanical models for predicting potential childbirth mode. Larger multicenter studies should confirm our results and evaluate their clinical significance in the decision making to ensure safe childbirth and optimal maternal and perinatal outcomes.

Mode of Delivery, Birth Characteristics, and Early-Onset Non-Hodgkin Lymphoma in a Population-Based Case-Control Study

BACKGROUND

The etiology of non-Hodgkin lymphoma (NHL) in children and in adolescents and young adults (AYA) is not well understood.

METHODS

We evaluated potential associations between mode of delivery, birth characteristics, and NHL risk in a population-based case-control study, which included 3,064 cases of NHL [490 with Burkitt lymphoma, 981 with diffuse large B-cell lymphoma (DLBCL), and 978 with T-cell NHL) diagnosed at the age of 0 to 37 years in California during 1988 to 2015 and 153,200 controls frequency matched on year of birth. Odds ratios (OR) and 95% confidence intervals (CI) were estimated from an unconditional multivariable logistic regression model that included year of birth and birth characteristics.

RESULTS

Individuals born via cesarean section had a decreased risk of pediatric Burkitt lymphoma (age 0-14 years; OR = 0.71, 95% CI: 0.51-0.99) and pediatric T-cell NHL (OR = 0.73, 95% CI: 0.55-0.97) compared with those born vaginally. Having a birth order of second (OR = 0.73, 95% CI: 0.57-0.93) or third or higher (OR = 0.76, 95% CI: 0.58-0.99) was associated with a lower risk of pediatric T-cell NHL compared with first-borns. AYA (age 15-37 years) with a heavier birthweight had an elevated risk of DLBCL (OR for each kg = 1.16, 95% CI: 1.00-1.35). Associations between other birth characteristics, including plurality, maternal age, maternal education, and NHL risk, also exhibited variations across subgroups based on age of diagnosis and histologic subtype.

CONCLUSIONS

These findings support a role of mode of delivery and birth characteristics in the etiology of early-onset NHL.

IMPACT

This study underscores the etiologic heterogeneity of early-onset NHL.

The Hormonal Milieu by Different Labor Induction Methods in Women with Previous Cesarean Section: a Prospective Randomized Controlled Trial

The physiological pattern of hormonal and signaling molecules associated with labor induction is not fully clear. We conducted a preliminary study in order to investigate hormonal changes during labor induction in women with previous cesarean section. Eighty-seven women at term, with previous cesarean section, were randomized to undergo induction of labor by breast stimulation or intracervical balloon and compared with spontaneous labor (controls). Maternal serum levels of oxytocin, prostaglandin F2α, prostaglandin E2, prolactin, estradiol, and cortisol were analyzed at 0, 3, and 6 h post-induction initiation. Fetal umbilical cord hormones were measured. No significant difference was found in the induction-to-delivery time or mode of delivery between the induction groups. Maternal serum oxytocin levels decreased to a lesser extent in the breast stimulation group vs. the control group (p=0.003, p<0.001). In the breast stimulation and control groups, prostaglandin E₂ levels increased as labor progressed (p=0.005, 0.002, respectively). Prostaglandin F2α levels decreased over time in the balloon group (p=0.039), but increased in the control group (p=0.037). Both induction methods had similar outcomes. The hormonal studies ascertained the hypothesized mechanisms, with oxytocin level higher during breast stimulation and lower in balloon induction. These observations could help clinicians determine the appropriate method for cervical ripening in women with previous cesarean section. Larger future studies are needed to examine the effect of these hormonal trends on the rate of successful labor induction and complications, such as uterine rupture, in women with previous uterine scars. ClinicalTrials.gov Identifier NCT04244747.

Birth signalling hormones and the developmental consequences of caesarean delivery

Rates of delivery by caesarean section (CS) are increasing around the globe and, although several epidemiological associations have already been observed between CS and health outcomes in later life, more are sure to be discovered as this practice continues to gain popularity. The components of vaginal delivery that protect offspring from the negative consequences of CS delivery in later life are currently unknown, although much attention to date has focused on differences in microbial colonisation. Here, we present the case that differing hormonal experiences at birth may also contribute to the neurodevelopmental consequences of CS delivery. Levels of each of the 'birth signalling hormones' (oxytocin, arginine vasopressin, epinephrine, norepinephrine and the glucocorticoids) are lower following CS compared to vaginal delivery, and there is substantial evidence for each that manipulations in early life results in long-term neurodevelopmental consequences. We draw from the research traditions of neuroendocrinology and developmental psychobiology to suggest that the perinatal period is a sensitive period, during which hormones achieve organisational effects. Furthermore, there is much to be learned from research on developmental programming by early-life stress that may inform research on CS, as a result of shared neuroendocrine mechanisms at work. We compare and contrast the effects of early-life stress with those of CS delivery and propose new avenues of research based on the links between the two bodies of literature. The research conducted to date suggests that the differences in hormone signalling seen in CS neonates may produce long-term neurodevelopmental consequences.

Perinatal cortisol and blood glucose concentrations in bitches and neonatal puppies: effects of mode of whelping

The decision on how and when to assist whelping is crucial for the survival rate of puppies and health status of the dam. However, medical or surgical therapy in dystocia can impact both maternal and neonatal stress and glucose response differently. This study aims to compare perinatal cortisol and glucose among different modes of delivery in bitches and neonates. We analyzed 50 puppies derived from 27 healthy bitches. According to the condition at birth, bitches and their puppies were allocated into either a Eutocia Group (vaginal birth with no whelping assistance), Fetal Dystocia Group (whelping assistance with fetal manipulation), Maternal Dystocia Group (whelping assistance because of partial uterine inertia corrected by oxytocin administration), or Cesarean Section Group (fetal or maternal dystocia bitches subjected to C-section). Maternal blood cortisol and glucose concentrations were analyzed during the perinatal period (prepartum, intrapartum, postpartum, and 1 h after postpartum). Neonatal blood samples were collected within 5 min and 1 h after birth for assessment of cortisol and glucose. Maternal dystocia bitches had higher cortisol concentrations at postpartum than the Fetal Dystocia Group. At 1 h postpartum, the Cesarean Section Group had higher cortisol concentrations compared with fetal dystocia bitches. The Eutocia Group presented increased cortisol concentrations at intrapartum and postpartum, whereas fetal dystocia bitches had higher intrapartum cortisol concentrations than at 1 h postpartum. The Maternal Dystocia Group presented higher postpartum cortisol concentrations than at prepartum and 1 h postpartum. Maternal glucose had a progressive increase throughout peripartum and was higher during postpartum and at 1 h postpartum. C-section bitches had the highest blood glucose concentration. Neonatal cortisol concentrations at birth were higher than 1 h after birth. Fetal dystocia puppies had higher cortisol concentrations, whereas caesarian section puppies had lower cortisol levels. Fetal dystocia and C-section puppies had higher glucose concentrations than the Eutocia Group. In conclusion, maternal dystocia leads to high cortisol concentrations in bitches immediately postpartum, whereas only fetal dystocia causes increased neonatal cortisol concentrations. Moreover, fetal dystocia and C-section are hyperglycemic obstetrical conditions for neonatal puppies; on the other hand, only C-section causes hyperglycemia in bitches.

Cesarean delivery and infant cortisol regulation

BACKGROUND

Cesarean delivery reduces the risk of infant and maternal morbidity and mortality when medically indicated, however, the cesarean delivery rate is estimated to be two to three times higher than medically necessary. The World Health Organization and American College of Obstetricians and Gynecologists have expressed concern over the high rates of cesarean delivery, citing evidence that cesarean delivery has negative short- and long-term consequences for the health of the infant, mother, and for future pregnancies. Infants delivered by cesarean are at an increased risk of metabolic disease and immune dysfunction throughout the lifespan. Preliminary research suggests that the hypothalamic pituitary adrenal (HPA) axis is a plausible pathway linking cesarean delivery to poor health later in life. The present study examines the relation between mode of delivery and HPA axis function in six-month-old infants. We also examine whether the cesarean delivery was elective or indicated altered to the relation between mode of delivery and infant cortisol profiles.

METHODS

The sample included 136 mother/infant pairs. Thirty-nine women delivered by cesarean and 97 delivered vaginally. Maternal and infant medical records were reviewed for prenatal medical history and birth outcomes. Infant saliva was collected for cortisol analysis at a 6-month well-baby checkup. Samples were collected upon arrival to the appointment (baseline) and 20 min after exposure to a painful stressor, the inoculation procedure (response). A mixed model ANCOVA was conducted to determine whether salivary cortisol concentrations differed between the two delivery groups. To examine whether complications related to having an indicated cesarean delivery contributed to any association between mode of delivery and cortisol production, cortisol concentrations were compared between the subgroup of infants whose cesarean deliveries were elective (e.g. maternal request or previous cesarean delivery) to infants delivered vaginally.

RESULTS

Infants delivered by cesarean had lower cortisol concentrations at baseline and after the inoculation procedure compared to those delivered vaginally. Further, the relation between mode of delivery and cortisol levels persisted even when the analyses were restricted to compare only the elective cesarean deliveries (e.g. maternal request or previous cesarean delivery) to those delivered vaginally.

DISCUSSION

This study provides evidence for an association between cesarean delivery and infant HPA axis function in infancy. Findings are consistent with the hypothesis that the HPA axis is a plausible pathway that links cesarean delivery with long-term health outcomes.

Pediatrics Consequences of Caesarean Section-A Systematic Review and Meta-Analysis

BACKGROUND

Cesarean section is a surgical procedure, which is the most frequently performed in gynecology and obstetrics. It is commonly believed that an operative delivery is a less painful and safer mode of delivery, which translates into an increasing number of the procedures performed without medical indications. The maternal sequelae of cesarean sections are well elucidated and widely discussed in the literature, while long-term neonatal consequences still remain the issue of research and scientific dispute. The aim of the present paper was to perform a systematic review of current literature regarding pediatrics consequences of cesarean section.

METHODS

We reviewed available data from PubMed, Science Direct as well as Google Scholar bases concerning early and long-term neonatal sequelae of operative deliveries. The following key words were used: "cesarean section", "caesarean section", "neonatal outcomes", "respiratory disorders", "asthma", "obesity", "overweight", and "neurological disorders". A total of 1636 papers were retrieved out of which 27 were selected for the final systematic review whereas 16 articles provided data for meta-analysis. Statistical analyses were performed using RevMan 5.4. To determine the strength of association between the caesarean section and respiratory tract infections, asthma, diabetes type 1 as well as obesity the pooled odds ratios (OR) with the 95% confidence intervals (CI) were calculated.

RESULTS

Conducted meta-analyses revealed that caesarean section is a risk factor for respiratory tract infections (pooled OR = 1.30 95%CI 1.06-1.60, p = 0.001), asthma (pooled OR = 1.23 95%CI 1.14-1.33, p < 0.00001) as well as obesity (pooled OR = 1.35 95%CI 1.29-1.41, p < 0.00001) in offspring.

CONCLUSIONS

The results of the studies included indicated that children delivered by cesarean section more commonly developed respiratory tract infections, obesity and the manifestations of asthma than children delivered vaginally. The risk of developing diabetes mellitus type 1 or neurological disorders in offspring after caesarean section is still under discussion.

Cesarean section and risk of childhood leukemia: a systematic review and meta-analysis

BACKGROUND

A large number of studies pointed that being delivered by cesarean section (CS) would affect the health outcomes of offspring, however, whether CS would affect the risk of childhood leukemia remained uncertain. This study conducted a meta-analysis to quantitatively evaluate whether being delivered by CS would influence the onset of childhood leukemia.

METHODS

PubMed, Embase and Web of Science databases were searched from 3rd June, 1950 to 13th October, 2019 to identify the literature, which examined the relationship between CS and childhood leukemia. This study used Newcastle-Ottawa Scale to assess the quality of literature. Subgroup analyses were conducted on region, mode of delivery, design of the study and number of confounders adjusted. Egger's test and Begg's test were performed to evaluate possible publication bias.

RESULTS

The pooled odds ratio (OR) estimates illustrated that children delivered by CS had a higher risk of developing leukemia [OR 1.10, 95% confidence interval (CI) 1.04-1.17, P = 0.002] and lymphoblastic leukemia (OR 1.12, 95% CI 1.03-1.23, P = 0.009), while a significant association for myeloid leukemia was not observed (OR 1.05, 95% CI 0.92-1.20, P = 0.451). Results of subgroup analyses indicated that elective CS would increase the risk of childhood lymphoblastic leukemia (OR 1.16, 95% CI 1.06-1.27, P = 0.002). However, a statistical relationship between emergency CS and lymphoblastic leukemia was not observed (OR 1.07, 95% CI 0.93-1.23, P = 0.364).

CONCLUSIONS

CS would increase the risk of childhood lymphoblastic leukemia. It is worth noting that subgroup analyses shows that elective CS rather than emergency CS increases the risk of lymphoblastic leukemia in offspring.

The role of maternal environment on calibrating "Mini Puberty" in early infant development

The postnatal period is a time of increased brain development and plasticity which have enduring influences on brain and behavior. Infants demonstrate a transient surge in testosterone (T) during development referred to as "mini puberty". The utility of studying mini puberty in psychobiology has only recently emerged. Life-history theory postulates that infants "use" the maternal environment-pre and postnatally-to calibrate growth and timing of sexual maturity. As such, variability in infant T levels is not arbitrary and can be predicted by theory. We examine the role of maternal pre- and postnatal cortisol. Using saliva samples (n = 193 dyads), we predicted that higher levels of maternal cortisol are associated with higher levels of infant T. We found only maternal postnatal cortisol had a relationship with infants' mini puberty. This relationship was in the predicted direction and remained after controlling for numerous variables. Discussion will include the potential role of mini puberty as an inflection point where systems related to growth, sexual maturation, and psychosexual behavior can be calibrated and coordinated.

Does the Caesarean Section Impact on 11β HSD2 and Fetal Cortisol?

Purpose: Comparison of the activity of 11beta-hydroxysteroid dehydrogenase type 2 in the placenta and the umbilical cord blood cortisol level between caesarean sections with or without uterine contraction and vaginal delivery groups. Cortisol is the main stress hormone responsible for the normal adaptation of the neonate to extrauterine life. The disorders resulting from a dysfunction of the 11β-HSD 2–cortisol system can explain the higher risk of developing diseases in children born by caesarean section. Methods: 111 healthy, pregnant women in singular pregnancy at term of delivery were included into the study. The study comprised 11β-HSD 2 in placental tissue from 49 pregnant women delivering by elective caesarean section and 46 pregnant women delivering by vagina. In 16 cases of the elective caesarean section, regular uterine contractions were declared. Cortisol level was estimated in umbilical cord blood directly after delivery. Results: We found no statistically significant differences in the activity of 11β-HSD 2 in placentas delivered via caesarean sections (29.61 on average in elective caesarean sections and 26.65 on average in intrapartum caesarean sections) compared to vaginal deliveries (31.94 on average, p = 0.381), while umbilical cord blood cortisol in the elective caesarean sections group was significantly lower (29.86 on average) compared to the vaginal deliveries (55.50 on average, p < 0.001) and intrapartum caesarean sections (52.27 on average, p < 0.001). Conclusions: The model of placental 11β-HSD 2 activity and umbilical cord blood cortisol concentration seems to be significant in conditions of stress associated with natural uterine contractions in labour.

Associations of per-/polyfluoroalkyl substances with glucocorticoids and progestogens in newborns

BACKGROUND

Exposure to per-/polyfluoroalkyl substances (PFASs) can disrupt endocrine hormones in humans. Prior studies have focused on the harmful effects of the two traditional per-/polyfluoroalkyl substances (PFASs), perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Other PFASs, used as the replacements of PFOS and PFOA, are widely and increasingly detected in humans. Whether these replacements influence glucocorticoids and progestogens in newborns remains unknown.

OBJECTIVE

To investigate the associations between exposures of PFOS, PFOA and their replacements and glucocorticoids and progestogens in newborns.

METHODS

We measured the concentrations of 13 PFASs, 3 glucocorticoids (11-deoxycortisol, cortisol and cortisone) and 2 progestogens [progesterone, 17-hydroxyprogesterone (17OHP)] in the cord sera of 374 neonates in a birth cohort from Wuhan, China, between 2013 and 2014. We evaluated the associations of each PFAS with glucocorticoids and progestogens using multiple linear regression models, and multiple comparisons were additionally corrected via false discovery rates (FDR).

RESULTS

Out of the 13 PFASs, 9 were detected in over 95% of cord sera. The Chinese specific PFOS replacement - 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA, trade name F-53B) was positively associated with 13.13% change in cortisol in girls (95% CI = 4.47%, 22.52%, for each IQR increase in 6:2 Cl-PFESA). Seven PFASs had positive associations with the precursor of cortisol, namely 11-deoxycortisol (percent change ranged from 6.41% to 11.24%, for each IQR increase in PFASs). Perfluorobutane sulfonate (PFBS) in cord sera was positively associated with progesterone in the linear model, whereas PFOS and perfluorohexane sulfonate (PFHxS) levels were associated with progesterone in the quartile models. No PFASs were related to 17OHP or cortisone.

CONCLUSIONS

In this study, PFOS, PFOA and/or their replacements were positively associated with progesterone, cortisol and 11-deoxycortisol in newborns. These results suggested that not only PFOS and PFOA, but also other PFASs have potential impacts on glucocorticoids and progestogens in newborns.

Salivary cortisol levels as a biomarker for severity of withdrawal in opioid-exposed newborns

BACKGROUND

Scoring tools used to quantify withdrawal in infants with neonatal abstinence syndrome (NAS) are often confounded by subjective measurements. This study assessed salivary cortisol as an objective biomarker of withdrawal severity in opioid-exposed newborns.

METHODS

A prospective study was conducted in 25 full-term opioid-exposed newborns monitored for NAS. Morning and evening salivary cortisol levels were collected starting within 48 h post birth until initiation of pharmacologic treatment for withdrawal (Pre-Treatment) or when the infant was discharged without pharmacotherapy (No Treatment).

RESULTS

Cortisol levels in the Pre-Treatment group (n = 11) were significantly higher within the first week of life (median 1.74 µg/dl) than in the No Treatment group (n = 11; median 0.72 µg/dl; P = 0.003); three infants had inadequate saliva volume for cortisol assay. Cortisol significantly decreased after 72 h post birth among infants discharged without pharmacotherapy (≤72 h median 1.25 µg/dl; ≥72 h median 0.58 µg/dl; P = 0.022), whereas cortisol remained elevated for infants subsequently treated for severity of withdrawal. No cortisol circadian rhythm was observed for either group.

CONCLUSIONS

Salivary cortisol in opioid-exposed newborns may provide an index of stress and help identify infants who will have more severe clinical presentation of NAS. Such a biomarker would allow risk stratification for early treatment and discharge decisions.

Effects of preterm birth induced with or without exogenous glucocorticoids on the ovine glucose-insulin axis

Antenatal exogenous glucocorticoids (ANG) are standard management for women at risk of preterm birth but are reputed to impair glucose tolerance in preterm offspring. We compared lambs born preterm (137 days gestation) following labour induced with exogenous glucocorticoids (G-Prem, glucocorticoid-induced preterm group), or with a progesterone synthesis inhibitor (NG-Prem, non-glucocorticoid-induced preterm group), with term-born lambs (Term; 149 days). We assessed glucose tolerance, insulin secretion and sensitivity at 4 and 10 months n = 11-14/group) and pancreatic and hepatic gene and protein expression at 4 weeks post-term (4 weeks; n = 6/group) and 12 months (12 months; n = 12-13/group). NG-Prem had higher plasma glucose concentrations than G-Prem, but not Term, at 4 months (Mean[SEM] mM: NG-Prem = 4.1[0.1]; G-Prem = 3.4[0.1]; Term = 3.7[0.1]; p = 0.003) and 10 months (NG-Prem = 3.9[0.1]; G-Prem = 3.5[0.1]; Term = 3.7[0.1]; p = 0.01). Insulin sensitivity decreased from 4 to 10 months, in NG-Prem but not in Term (Mean[SEM] µmol·ml-1·kg-1·min-1·ng-1, 4 vs. 10 months: NG-Prem = 18.7[2.5] vs. 9.5[1.5], p < 0.01; Term: 12.1[2.8] vs. 10.4[1.5], p = 0.44). At 12 months, β-cell mass in NG-Prem was reduced by 30% vs. G-Prem (p < 0.01) and 75% vs. Term (p < 0.01) and was accompanied by an increased β-cell apoptosis: proliferation ratio at 12 months. At 12 months, pancreatic glucokinase, igf2 and insulin mRNA levels were reduced 21%-71% in NG-Prem vs. G-Prem and 42%-80% vs. Term. Hepatic glut2 mRNA levels in NG-Prem were 250% of those in G-Prem and Term. Thus, induction of preterm birth without exogenous glucocorticoids more adversely affected pancreas and liver than induction with exogenous glucocorticoids. These findings do not support that ANG lead to long-term adverse metabolic effects, but support an effect of preterm birth itself.

Elective and nonelective cesarean section and obesity among young adult male offspring: A Swedish population-based cohort study

BACKGROUND

Previous studies have suggested that cesarean section (CS) is associated with offspring overweight and obesity. However, few studies have been able to differentiate between elective and nonelective CS, which may differ in their maternal risk profile and biological pathway. Therefore, we aimed to examine the association between differentiated forms of delivery with CS and risk of obesity in young adulthood.

METHODS AND FINDINGS

Using Swedish population registers, a cohort of 97,291 males born between 1982 and 1987 were followed from birth until conscription (median 18 years of age) if they conscripted before 2006. At conscription, weight and height were measured and transformed to World Health Organization categories of body mass index (BMI). Maternal and infant data were obtained from the Medical Birth Register. Associations were evaluated using multinomial and linear regressions. Furthermore, a series of sensitivity analyses were conducted, including fixed-effects regressions to account for confounders shared between full brothers. The mothers of the conscripts were on average 28.5 (standard deviation 4.9) years old at delivery and had a prepregnancy BMI of 21.9 (standard deviation 3.0), and 41.5% of the conscripts had at least one parent with university-level education. Out of the 97,291 conscripts we observed, 4.9% were obese (BMI ≥ 30) at conscription. The prevalence of obesity varied slightly between vaginal delivery, elective CS, and nonelective CS (4.9%, 5.5%, and 5.6%, respectively), whereas BMI seemed to be consistent across modes of delivery. We found no evidence of an association between nonelective or elective CS and young adulthood obesity (relative risk ratio 0.96, confidence interval 95% 0.83-1.10, p = 0.532 and relative risk ratio 1.02, confidence interval 95% 0.88-1.18, p = 0.826, respectively) as compared with vaginal delivery after accounting for prepregnancy maternal BMI, maternal diabetes at delivery, maternal hypertension at delivery, maternal smoking, parity, parental education, maternal age at delivery, gestational age, birth weight standardized according to gestational age, and preeclampsia. We found no evidence of an association between any form of CS and overweight (BMI ≥ 25) as compared with vaginal delivery. Sibling analysis and several sensitivity analyses did not alter our findings. The main limitations of our study were that not all conscripts had available measures of anthropometry and/or important confounders (42% retained) and that our cohort only included a male population.

CONCLUSIONS

We found no evidence of an association between elective or nonelective CS and young adulthood obesity in young male conscripts when accounting for maternal and prenatal factors. This suggests that there is no clinically relevant association between CS and the development of obesity. Further large-scale studies are warranted to examine the association between differentiated forms of CS and obesity in young adult offspring.

TRIAL REGISTRATION

Registered as observational study at ClinicalTrials.gov Identifier: NCT03918044.

The association between caesarean section delivery and later life obesity in 21-24 year olds in an Urban South African birth cohort

BACKGROUND

Obesity is an important public health problem and rates have reached epidemic proportions in many countries. Studies have explored the association between infants delivered by caesarean section and their later life risk of obesity, in many countries outside Africa. As a result of the increasing caesarean section and obesity rates in South Africa, we investigated the association in this country.

METHODS

This was a retrospective analysis of data that were collected from a prospective South African birth cohort (Birth to Twenty Plus), established in 1990. A total of 889 young adults aged 21-24 years were included in the analysis. Poisson regression models were fitted to assess the association between mode of delivery and early adulthood obesity.

RESULTS

Of the 889 young adults, 106 (11.9%) were obese while 72 (8.1%) were delivered by caesarean section; of which 14 (19.4%) were obese. Caesarean section delivery was significantly associated with obesity in young adults after adjusting for potential confounders like young adults' sex and birth weight, mothers' parity, and education (incidence rate ratio 1.64, 95% CI 1.01-2.68, p = 0.045).

CONCLUSION

The association of caesarean section with early adulthood obesity should be interpreted with caution because data on certain key confounding factors such as mothers' pre-pregnancy body mass index and gestational diabetes were not available. Further research from Africa, with larger sample sizes and databases with useful linking of maternal and infant data, should be conducted.

Physiological and psychological stress responses to labor and delivery as expressed by salivary cortisol: a prospective study

BACKGROUND

Labor is considered a stressful event, yet no study has described the course of stress measured by cortisol during labor and postpartum.

OBJECTIVE

The objective of the study was to describe the patterns of physiological and psychological stress during labor as measured by salivary cortisol concentrations and stress questionnaires and their correlation to obstetric and neonatal outcomes.

STUDY DESIGN

This prospective, observational study included 167 women with low-risk, singleton, term deliveries at a tertiary academic center. Physiological stress was evaluated by salivary cortisol measurements and emotional stress by questionnaire (stress scale ranging from 0 to 10) during the latent phase, active phase, and full dilation stages of labor as well as 2 minutes, 2 hours, and 24 hours after delivery. Cord blood cortisol and pH were also obtained. Modes of delivery, complications during labor and delivery, and early neonatal outcomes were evaluated.

RESULTS

Salivary cortisol concentrations increased gradually from latent phase to active phase. The maximum increase was observed within 2 minutes of the delivery (from an average of 1.06 μg/dL to 1.67 μg/dL; 57% increase). Within 2 hours after delivery, cortisol decreased and reached a nongravid concentration after 24 hours (0.16 μg/dL). Cortisol concentrations during labor and up to 2 hours postpartum were above the average concentration of nongravid women (0.5 μg/dL). Women with epidural anesthesia had lower cortisol concentrations at complete dilation (P = .026) and 2 hours postpartum (P = .016) compared with women without epidural. Psychological stress peaked during latent and full dilation phases (mean 4.56 and 4.29, respectively). Maximum decrease from 4.29 to 2.04 (52%) occurred immediately postpartum. Cord cortisol was higher among women delivered by vacuum extraction compared with spontaneous vaginal delivery (17 ± 2 vs 11 ± 3.8, P = .03).

CONCLUSION

This study reveals the course of cortisol concentrations during labor for low-risk pregnancies, with maximum increase immediately postpartum. Subjective stress levels decreased over the course of labor. Salivary cortisol portrays stress during labor and may be used as a reference to evaluate complicated pregnancies and to evaluate the role of cortisol during these deliveries.

Investigating Stress Response during Vaginal Delivery and Elective Cesarean Section through Assessment of Levels of Cortisol, Interleukin 6 (IL-6), Growth Hormone (GH) and Insulin-Like Growth Factor 1 (IGF-1)

Background: How do stress related phenomena during labor differ between vaginal delivery (VD) and elective cesarean section (CS), remains of heightened interest. The purpose of this study is to investigate discrepancies regarding the stress response during VD and CS. Methods: Cortisol, interleukin 6 (IL-6), growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels from parturients’ peripheral blood were evaluated on three time-points, namely during the first stage of labor (TP1), two hours post labor (TP2) and 48 h post labor (TP3). Levels were also evaluated from the umbilical cord blood. A total of 50 women were enrolled in this prospective cohort study, with 24 and 26 subjected to CS and VD, respectively. Results: No statistically significant differences were observed between the two groups at TP1. Only GH levels presented the same pattern during the three time-points among both groups. In the umbilical cord blood, the CS group presented statistically significant higher IGF-1 and GH levels. In the umbilical cord blood, IGF-1 and GH levels were positively correlated, while GH and cortisol levels were negatively correlated. Conclusion: CS is a less stressful procedure than VD and is further associated with less intense inflammation, albeit with a longer inflammatory response period. Labor physiology during CS differs considerably regarding respective observations during VD. This merits extensive investigation in order to decipher these data for optimal clinical practice and guidelines.

Adrenal function of extremely premature infants in the first 5 days after birth

Background There is limited data on adrenal function in the early days after birth in extremely premature infants. The relationship between plasma adrenocorticotrophic (ACTH) and cortisol hormone is central to the integrity of the hypothalamic-pituitary-adrenal (HPA) axis yet there are no studies examining this relationship in prematurity. Methods The aim of this study was to examine the relationship between early morning plasma cortisol and ACTH concentrations during the first 5 days after birth in infants born at less than 28 weeks' gestation and to identify any independent factors that determine plasma cortisol levels in these infants during extreme prematurity. We prospectively studied early morning plasma ACTH and cortisol concentrations in infants born below 28 weeks' gestation during the first 5 days of birth. Plasma cortisol was measured without extraction, using DPC Immulite® 2000 using a solid phase 2 site chemiluminescent immunometric assay. ACTH was measured using a radioimmunoassay. Spearman's correlation was used to examine the relationship between cortisol and ACTH. Multiple regression analysis was used to examine the relationship between plasma cortisol and clinical risk index for babies (CRIB) score, antenatal dexamethasone, mode of delivery and gestation. Results There were 95 infants (53 males) of mean gestation 25.3 ± 1.3 standard deviation (SD) (range 23-27 + 6) weeks. The mean birth weight was 809 ± 17.0 g. The mean plasma cortisol was 400.5 ± 42.6 nmol/L and the mean plasma ACTH was 4.5 ± 0.9 pmol/L. Early morning plasma cortisol correlated significantly with gestation (R = 0.4, p = 0.005). Early morning plasma ACTH did not correlate with early morning plasma cortisol (R = -0.12, p = 0.7). Multiple regression analysis showed that gestation was the only independent determinant of early morning plasma cortisol concentration (beta coefficient = -0.4, p = 0.04). Conclusions The relationship between early morning plasma ACTH and plasma cortisol is either not established or is impaired in infants of less than 28 weeks' gestation in the first 5 days after birth. The plasma cortisol level is mainly determined by gestation and is not directly related to illness severity, antenatal steroids or plasma ACTH in these infants in the first 5 days after birth.

Maternal Blood Pressure, Cord Glucocorticoids, and Child Neurodevelopment at 2 Years of Age: A Birth Cohort Study

BACKGROUND

Pregnancy hypertensive disorders have impaired neurodevelopment in offspring. We aimed to explore the association of normal range maternal blood pressure (BP) with child neurodevelopment, as well as the possible role of placental 11-beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2) therein.

METHODS

Among 1,008 mother-child pairs recruited in Wuhan, China, in 2013-2015, we measured maternal third-trimester BP (systolic BP (SBP) and diastolic BP (DBP)) and cord glucocorticoids (cortisol and cortisone), a marker reflecting placental 11β-HSD2 activity. We evaluated child neurodevelopment using the Bayley Scales of Infant Development (BSID) with obtaining the Mental and Psychomotor Development Index (MDI and PDI). Multiple regression and mediation analysis were performed to estimate the effect.

RESULTS

Each 5 mm Hg increase in maternal third-trimester SBP was associated with 1.54 points decrease in MDI (95% confidence interval (CI) = -2.60, -0.48) and 1.23 points decrease in PDI (95% CI = -2.14, -0.31); similar association was observed between DBP and BSID (adjusted β = -1.32; 95% CI = -2.53, -0.10 for MDI and -1.37; 95% CI = -2.42, -0.33 for PDI). Also, we found significant associations between cord cortisol/cortisone ratio and PDI (adjusted β = 2.95; 95% CI = 0.91, 4.99), as well as between maternal BP and cord cortisol/cortisone ratio (adjusted β = -0.03; 95% CI = -0.06, -0.01 for both SBP and DBP). Mediation analysis revealed that cord cortisol/cortisone ratio explained 6.29% of the association between SBP and PDI, and 6.85% between DBP and PDI.

CONCLUSIONS

Increased maternal normal range BP may affect child neurodevelopment. Furthermore, placental 11β-HSD2 activity might be involved in the process.

Association of Elective and Emergency Cesarean Delivery With Early Childhood Overweight at 12 Months of Age

IMPORTANCE

Global cesarean delivery (CD) rates have more than doubled over the past 2 decades, with an increasing contribution from elective CDs. Cesarean delivery has been linked to early childhood overweight and obesity, but limited studies have examined elective and emergency CDs separately.

OBJECTIVE

To investigate whether elective or emergency CD was associated with risk of early childhood overweight.

DESIGN, SETTING, AND PARTICIPANTS

Data were drawn from the Growing Up in Singapore Toward Healthy Outcomes (GUSTO) study, an ongoing prospective mother-child birth cohort study. Participants were pregnant women aged 18 years or older with homogeneous parental ethnic background in their first trimester recruited between June 2009 and September 2010 (n = 1237) at 2 major public hospitals in Singapore. Those with type 1 diabetes or undergoing chemotherapy or psychotropic drug treatment were excluded. Data analysis commenced in October 2017.

EXPOSURES

Delivery mode obtained from clinical records. Elective and emergency CD examined separately against vaginal delivery as reference.

MAIN OUTCOMES AND MEASURES

Body mass index-for-age z scores at age 12 months calculated based on 2006 World Health Organization Child Growth Standards from infant weight and recumbent crown-heel length measurements taken between December 2010 and April 2012. High body mass index status at risk of overweight was defined as a z score of more than 1 SD and less than or equal to 2 SDs. Overweight was defined as a z score of more than 2 SDs.

RESULTS

Among 727 infants analyzed (51.2% [372] male), 30.5% (222) were born via CD, of which 33.3% (74) were elective. Prevalence of at risk of overweight and overweight at age 12 months was 12.2% (89) and 2.3% (17), respectively. Elective CD was significantly associated with at risk of overweight or overweight at age 12 months after adjusting for maternal ethnicity, age, education, parity, body mass index, antenatal smoking, hypertensive disorders of pregnancy, gestational diabetes, and sex-adjusted birth weight-for-gestational age (odds ratio, 2.05; 95% CI, 1.08-3.90; P = .03). The association persisted after further adjustment for intrapartum antibiotics and first 6 months infant feeding, 2 potential mediators of early childhood overweight and obesity (odds ratio, 2.02; 95% CI, 1.05-3.89; P = .04). No significant associations were found for emergency CD. Analysis with multiple imputation for missing covariates yielded similar results.

CONCLUSIONS AND RELEVANCE

Choice of delivery mode may influence risk of early childhood overweight. Clinicians are encouraged to discuss potential long-term implications of elective CD on child metabolic outcomes with patients who intend to have children.

The effect of the modes of delivery on the maternal and neonatal dynamic thiol-disulfide homeostasis

Background: Thiols are organic compounds containing sulfhydryl groups which exert antioxidant effects via dynamic thiol-disulfide homeostasis. The shift towards disulfide indicates the presence of oxidative environment. The thiol-disulfide homeostasis has not been studied in different mode of delivery before. Aims: To investigate the effects of mode of parturition on the thiol-disulfide homeostasis in mothers and term infants. Study design: The participants were grouped according to the mode of their delivery: group vaginal delivery (VD, n = 40) and group cesarean section (C/S, n = 40). Three serum samples were collected: from mothers at the beginning of labor, from the cord blood (CB), and from the infants at the 24th hour after birth. The dynamic thiol-disulfide homeostasis in both groups were compared. Results: The levels of native-thiol and total-thiol in CB were significantly higher in VD group than those with C/S group. The levels of disulfide were higher in infants born by C/S compared with those born by VD. The disulfide-to-native thiol ratio, disulfide-to-total thiol ratio, and native thiol-to-total thiol ratio were similar between two groups. Conclusion: Our results showed that the dynamic thiol-disulfide homeostasis of the neonate was greatly influenced by the way of delivery and supported that vaginally delivered infants have less oxidative stress.

Pregnancy and perinatal conditions and atopic disease prevalence in childhood and adulthood

BACKGROUND

Previous studies showed controversial results for the influence of pregnancy-related and perinatal factors on subsequent respiratory and atopic diseases in children. The aim of this study was to assess the association between perinatal variables and the prevalence of asthma, bronchial hyperreactivity (BHR), flexural eczema (FE), allergic rhinitis, and sensitization in childhood and early adulthood.

METHODS

The studied population was first examined in Munich and Dresden in 1995/1996 at age 9-11 years. Participants were followed until age 19-24 years using questionnaires and clinical examinations. Associations between perinatal data and subsequent atopic diseases were examined using logistic regression analyses adjusting for potential confounders.

RESULTS

Cesarean section was statistically significantly associated with BHR in early adulthood (odds ratio 4.8 [95% confidence interval 1.5-15.2]), while assisted birth was associated with presence of asthma symptoms in childhood (2.2 [1.2-3.9]), FE symptoms (2.2 [1.2-4.3]) and doctor's diagnosis of atopic dermatitis (1.9 [1.0-3.4]) in childhood, and sensitization in early adulthood (2.2 [1.1-4.3]). Lower birth length (1.9 [1.1-3.2]), lower birthweight (0.5 [0.3-0.9]), and higher birthweight (0.6 [0.4-1.0]) were predictive of sensitization in early adulthood compared to average birth length and birthweight, respectively. None of the other perinatal factors showed statistically significant associations with the outcomes.

CONCLUSIONS

Our results indicate that children who are born by cesarean section and especially by assisted birth, might be at greater risk for developing asthma, FE, and sensitization and should hence be monitored. Prenatal maternal stress might partly explain these associations, which should be further investigated.

Basal and reactivity levels of cortisol in one-month-old infants born to overweight or obese mothers from an ethnically and racially diverse, low-income community sample

Establishing typical values of the steroid hormone cortisol at rest and after challenge is critical for understanding how environmental factors impact stress regulation and overall development, beginning at birth. Yet most extant samples are small or based upon low-risk populations, and few studies address the potential role of maternal weight during pregnancy in their study designs or sampling strategy. Here we report basal and reactivity levels of salivary cortisol within a racially and ethnically diverse sample of 132 infants approximately one month of age (Age in days: M=37.61, SD=7.27) born to lower income overweight or obese mothers. Reactivity was assessed in response to a multi-domain infant stressor paradigm, which included assessment via the Newborn Behavioral Observation (NBO) system and extensive anthropometric measurements. Sample means for basal, post stressors, and reactivity to the NBO were significantly lower than those reported in reviews of low-risk samples. Parity was associated with cortisol levels such that first-born infants had lower resting cortisol and higher reactivity than infants born to multiparous women. Latino infants had lower basal cortisol. No other demographic characteristics significantly predicted cortisol. The variability in cortisol levels present in this sample suggests that considerable psychophysiological diversity may exist in samples of low-SES or high-risk participants. Findings provide useful ranges for samples of racially and ethnically diverse newborns from low-income families.

Cesarean Delivery and Risk of Infant Leukemia: A Report from the Children's Oncology Group

Background: Studies have reported increased risks of pediatric acute lymphoblastic leukemia (ALL) among children born by cesarean delivery (CD). However, no previous study has examined the impact of CD on risk of infant leukemia specifically.Methods: In this study, 443 infants diagnosed with acute leukemia, including both ALL and acute myelogenous leukemia (AML), were identified at Children's Oncology Group institutions between January 1996 and December 2006; 324 controls frequency matched by year of birth were identified though random digit dialing and random selection from U.S. birth registries. Using interview data and, for a subset of participants, medical record data, we analyzed CD overall and by indications that likely resulted in pre-labor CD (PLCD) or emergency CD (ECD). Odds ratios (ORs) and 95% confidence intervals (CIs) for risk of ALL and AML were estimated using multivariable unconditional logistic regression models, adjusted for year of birth, birth weight, and maternal race.Results: We observed an increased point estimate for the association between CD and ALL (OR, 1.52 and 95% CI, 1.02-2.25). We did not observe an association between CD and AML (OR, 1.02 and 95% CI, 0.64-1.62). In analyses of indication for CD, we observed elevated effect estimates for the associations of both PLCD and ECD and infant ALL.Conclusions: Our analysis suggests an increased risk of infant ALL following CD, including both PLCD and ECD. Altered microbiota colonization may be involved in development of leukemia in infants, but clear biological mechanisms have yet to be determined.Impact: This study provides the first in-depth examination of CD and infant leukemia. Cancer Epidemiol Biomarkers Prev; 27(4); 473-8. ©2018 AACR.

Mode of delivery and child and adolescent psychological well-being: Evidence from Hong Kong's "Children of 1997" birth cohort

Mode of delivery (vaginal or cesarean section) is thought to affect gut microbiota, which in turn may affect psychological well-being. As such, mode of delivery is potentially a modifiable factor for psychological well-being. Here we examined the association of mode of delivery with child and adolescent psychological well-being. We used multivariable linear regression in a population-representative Hong Kong Chinese birth cohort, “Children of 1997,” to examine the adjusted associations of mode of delivery with behavioral problems assessed from parent-reported Rutter score at ~7 (n = 6294) and ~11 years (n = 5598), self-esteem assessed from self-reported Culture-Free Self-Esteem Inventory score at ~11 years (n = 6937) and depressive symptoms assessed from self-reported Patient Health Questionnaire-9 score at ~13 years (n = 5797). Cesarean Section (CS) was associated with children born in private hospitals, boys, and firstborns, higher maternal body mass index, higher maternal age, preeclampsia, higher socioeconomic position (SEP) and maternal birth in Hong Kong. CS was unrelated to behavior, self-esteem and depressive symptoms adjusted for infant characteristics (sex, gestational age, birthweight, parity and breast feeding), maternal characteristics (mother’s age and place of birth) and SEP. In a developed non-Western setting, mode of delivery was not clearly associated with childhood or early adolescent psychological well-being.

Glucocorticoids are lower at delivery in maternal, but not cord blood of obese pregnancies

Glucocorticoids are vital for lung maturation. We previously showed that cortisol is lower in obese pregnancy. Whether this is maintained at delivery is unknown but is clinically relevant as maternal and cord blood cortisol levels are correlated and offspring of obese are more likely to need neonatal respiratory support. We hypothesized that glucocorticoids are lower in maternal and cord blood at delivery in obese pregnancies. Glucocorticoids (cortisol and corticosterone) and their inactive versions (cortisone and 11-dehydrocorticosterone) were measured by LC-MS/MS in maternal and cord plasma from 259 Caucasian women at delivery (BMI 18–55 kg/m²). Analyses adjusted for labour status, delivery mode, offspring gender, birthweight and gestational age. Cortisol and corticosterone were significantly higher in maternal than cord blood. Inactive versions were significantly higher in cord than maternal blood. Increased maternal BMI associated with lower maternal cortisol, corticosterone and 11-dehydrocorticosterone. Despite significant positive correlations between maternal and cord blood glucocorticoid levels, increased maternal BMI was not associated with lower cord blood glucocorticoid levels. Conditions at delivery may overcome any potential negative effects of low maternal glucocorticoids on the fetus in the short-term. This may not preclude the longer-term effects of fetal exposure to lower glucocorticoid levels during obese pregnancy.

Maternal predictors and quality of umbilical cord blood units

The aim of the study was to determine the relationship between the maternal age at delivery and selected properties of the cord blood stem cells. The study included 50 pregnant women aged between 18 and 38 years in which spontaneous labors or elective cesarean sections were performed. Umbilical cord blood was collected immediately after the women were delivered of newborns. The samples were analyzed in the Polish Stem Cells Bank in Warsaw. The highest mean WBC level (p < 0.05) was observed in the umbilical blood collected from patients aged 35 years and more. Similarly, the highest mean cell viability was observed in the umbilical cord blood collected from patients aged 35 and more. There were no statistically significant correlations between the CD34+ cells count and mean cell viability in the umbilical cord blood and the maternal age. With the significance level at p < 0.001, the females after spontaneous labor revealed a visibly higher WBC level than patients after a cesarean section. The higher mean WBC concentration (24.95 thousand/μl) was observed in the umbilical cord blood of patients aged 35 and more after spontaneous labors. In the same group, the umbilical cord blood was also characterized by the highest mean cell viability (98.72%). The number of nucleated cells in the umbilical cord blood collected in the perinatal period increases together with the maternal age. In the course of physiological spontaneous labors, the collected umbilical cord blood has more nucleated cells as compared with elective caesarian sections.

Decreased neonatal pain response after vaginal-operative delivery with Kiwi OmniCup versus metal ventouse

BACKGROUND

Vaginal delivery, especially operative assisted vaginal delivery, seems to be a major stressor for the neonate. The objective of this study was to evaluate the stress response after metal cup versus Kiwi Omnicup® ventouse delivery.

METHODS

The study was a secondary observational analysis of data from a former prospective randomised placebo controlled multicentre study on the analgesic effect of acetaminophen in neonates after operative vaginal delivery and took place at three Swiss tertiary hospitals. Healthy pregnant women ≥35 weeks of gestation with an estimated fetal birth weight above 2000 g were recruited after admission to the labour ward. Pain reaction was analysed by pain expression score EDIN scale (Échelle Douleur Inconfort Nouveau-Né, neonatal pain and discomfort scale) directly after delivery. For measurement of the biochemical stress response, salivary cortisol as well as the Bernese Pain Scale of Newborns (BPSN) were evaluated before and after an acute pain stimulus (the standard heel prick for metabolic testing (Guthrie test)) at 48-72 h.

RESULTS

Infants born by vaginal operative delivery displayed a lower pain response after plastic cup than metal cup ventouse delivery (p < 0.001), but the pain response was generally lower than expected and they recovered fully within 72 h.

CONCLUSIONS

Neonatal pain response is slightly reduced after use of Kiwi OmniCup® versus metal cup ventouse.

TRIAL REGISTRATION

Trial was registered under under NCT00488540 on 19th June 2007.

Cesarean Section and Risk of Childhood Acute Lymphoblastic Leukemia in a Population-Based, Record-Linkage Study in California

The relationship of mode of delivery to risk of childhood acute lymphoblastic leukemia (ALL) is uncertain. After linking birth records and cancer registry data from California, we conducted a population-based case-control study to investigate the role of delivery by cesarean section (C-section) in the etiology of childhood ALL. This study included 5,081 cases and 18,927 matched controls born in 1978-2009; more detailed data were available on type of C-section (i.e., elective vs. emergency) for a subset of 1,552 cases and 5,688 controls. No association was observed between C-section overall and childhood ALL risk (<15 years of age), but elective C-section was associated with a significantly elevated risk of ALL (odds ratio (OR) = 1.17, 95% confidence interval (CI): 1.01, 1.36). At the peak ages of ALL incidence (2-4 years), C-section was associated with an 11% higher risk of ALL (OR = 1.11, 95% CI: 1.01, 1.22) compared with vaginal delivery, and the magnitude of the association was larger for elective C-section (OR = 1.38, 95% CI: 1.11, 1.70). Emergency C-section was not associated with childhood ALL. Because of design features minimizing nonparticipation and inaccurate recall, this record linkage-based study is less prone to bias. Our results suggest that delivery by elective C-section was associated with a higher risk of childhood ALL, especially at the peak ages of incidence. It is important to evaluate possible mechanisms, because this potential risk factor is modifiable.

Early-life factors affect risk of pain and fever in infants during teething periods

AIM

This longitudinal study aimed to investigate the prevalence of teething-related pain and fever and the early-life factors that may affect the risk of experiencing these disturbances within the first 1.5 years of life.

MATERIALS AND METHODS

Participants were recruited (n = 1033) through the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort (n = 1237). Interviews were performed tri-monthly regarding the prevalence of teething pain and fever in children from 6 to 18 months of age. Crude and multivariable analyses were conducted using Poisson-log regression models.

RESULTS

Prevalence rates for teething pain and fever were 35.5 and 49.9 % respectively. Multivariable Poisson regression analysis showed maternal second-hand tobacco smoke (SHS) exposure to increase the risk of both pain (mean ratio = 1.35; p = 0.006) and fever (mean ratio = 1.22; p = 0.025), whereas SHS exposure plus active smoking further increased risk of teething pain in the children (mean ratio = 1.89; p = 0.029). Delivery via Caesarean section increased risk of teething pain (mean ratio = 1.27; p = 0.033), while prenatal plasma vitamin D insufficiency lowered such a risk (mean ratio = 0.62; p = 0.012). Compared to Chinese infants, Indian babies exhibited lower risk of teething pain and fever (both p ≤ 0.001).

CONCLUSIONS

Early-life factors such as tobacco smoke exposure and vitamin insufficiency during pregnancy, ethnicity and childbirth via Caesarean section may significantly affect the child's susceptibility to teething-related pain and fever.

CLINICAL RELEVANCE

Knowledge of prevalence and risk factors of teething disturbances may better equip primary caregivers and healthcare professionals to accurately detect teething-related local and/or systemic signs/symptoms and effectively facilitate tobacco cessation among pregnant women.

Comparison of Oxidative Stress Markers and Serum Cortisol between Normal Labor and Selective Cesarean Section Born Neonates

INTRODUCTION

An imbalance between antioxidant and oxidant-generating systems in newborns can cause oxidative damage. The effect of modes of delivery on oxidative stress in neonates is not fully investigated.

AIM

This study was aimed to examine the effects of modes of delivery on oxidative stress markers and cortisol in newborns.

MATERIALS AND METHODS

In this study 60 term neonates {30 born via Normal Delivery (ND) and 30 born via elective Caesarean Delivery (CS)} at birth were enrolled. Glutathione Peroxidase (GPx), Catalase (CAT) and Superoxide Dismutase (SOD) activities were determined in umbilical cord blood in all neonates. Moreover serum cortisol, uric acid and Total Antioxidant Capacity (TAC) were measured.

RESULTS

GPx and SOD activities in cesarean born neonates were significantly higher than those of control subjects (p<0.05). TAC and CAT were not significantly different between the two groups. Serum cortisol was lower in caesarean born subjects as compared to normal born neonates. On the other hand uric acid concentration was higher in caesarean born neonates.

CONCLUSION

The obtained data indicated that babies born via caesarean section might be predisposed to pathological conditions due to altered antioxidant levels.

Caesarean delivery and risk of childhood leukaemia: a pooled analysis from the Childhood Leukemia International Consortium (CLIC)

BACKGROUND

Results from case-control studies have shown an increased risk of acute lymphoblastic leukaemia (ALL) in young children born by caesarean delivery, and prelabour caesarean delivery in particular; however, an association of method of delivery with childhood leukaemia subtypes has yet to be established. We therefore did a pooled analysis of data to investigate the association between childhood leukaemia and caesarean delivery.

METHODS

We pooled data from 13 case-control studies from the Childhood Leukemia International Consortium done in nine countries (Canada, Costa Rica, Egypt, France, Germany, Greece, Italy, New Zealand, and the USA) for births from 1970-2013. We analysed caesarean delivery overall and by indications that probably resulted in prelabour caesarean delivery or emergency caesarean delivery. We used multivariable logistic regression models, adjusted for child's birthweight, sex, age, ethnic origin, parental education, maternal age, and study, to estimate odds ratios (ORs) and 95% CIs for the risk of ALL and acute myeloid leukaemia (AML) in children aged 0-14 years at diagnosis.

FINDINGS

The studies provided data for 8780 ALL cases, 1332 AML cases, and 23 459 controls, of which the birth delivery method was known for 8655 (99%) ALL cases, 1292 (97%) AML cases, and 23 351 (>99%) controls. Indications for caesarean delivery were available in four studies (there were caesarean deliveries for 1061 of 4313 ALL cases, 138 of 664 AML cases, and 1401 of 5884 controls). The OR for all indications of caesarean delivery and ALL was 1·06 (95% CI 0·99-1·13), and was significant for prelabour caesarean delivery and ALL (1·23 [1·04-1·47]; p=0·018). Emergency caesarean delivery was not associated with ALL (OR 1·02 [95% CI 0·81-1·30]). AML was not associated with caesarean delivery (all indications OR 0·99 [95% CI 0·84-1·17]; prelabour caesarean delivery 0·83 [0·54-1·26]; and emergency caesarean delivery 1·05 [0·63-1·77]).

INTERPRETATION

Our results suggest an increased risk of childhood ALL after prelabour caesarean delivery. If this association is causal, maladaptive immune activation due to an absence of stress response before birth in children born by prelabour caesarean delivery could be considered as a potential mechanism.

FUNDING

National Cancer Institute.

Arginine Vasopressin and Copeptin in Perinatology

Arginine vasopressin (AVP) plays a major role in the homeostasis of fluid balance, vascular tonus, and the regulation of the endocrine stress response. The measurement of AVP levels is difficult due to its short half-life and laborious method of detection. Copeptin is a more stable peptide derived from the same precursor molecule, is released in an equimolar ratio to AVP, and has a very similar response to osmotic, hemodynamic, and stress-related stimuli. In fact, copeptin has been propagated as surrogate marker to indirectly determine circulating AVP concentrations in various conditions. Here, we present an overview of the current knowledge on AVP and copeptin in perinatology with a particular focus on the baby's transition from placenta to lung breathing. We performed a systematic review of the literature on fetal stress hormone levels, including norepinephrine, cortisol, AVP, and copeptin, in regard to birth stress. Finally, diagnostic and therapeutic options for copeptin measurement and AVP functions are discussed.

High-dose glucocorticoid therapy in the management of seizures in neonatal incontinentia pigmenti: a case report

Incontinentia pigmenti is an X-linked dominant disorder resulting from a mutation of IKBKG. This disorder has a classic dermatologic presentation, but neurologic involvement, with seizures and cortical infarction, can arise shortly after birth. There are no specific therapies available for the manifestations of incontinentia pigmenti. Here, we describe the clinical, electrographic, and neuroradiologic effect of systemic glucocorticoid therapy in a neonate with incontinentia pigmenti manifesting an epileptic encephalopathy. Treatment with dexamethasone led to a dramatic reduction in seizure activity and improvement in bullous lesions. A novel mutation in IKBKG is also reported.

Duration of gestation and mode of delivery affect the genes of transepithelial sodium transport in pulmonary adaptation

BACKGROUND

Respiratory distress due to inadequate lung liquid clearance is a significant problem in infants delivered late preterm or early term, especially by elective cesarean delivery (CD). Lung liquid clearance depends on epithelial ion transport and in animals is induced by glucocorticoids.

OBJECTIVES

In newborn late preterm and term infants to study airway epithelial gene expressions of epithelial sodium channel (ENaC), and the serum and glucocorticoid-inducible kinase 1 (SGK1), and their association with cortisol, mode of delivery, and gestational age (GA).

METHODS

Infants were delivered at 35(0/7)-41(6/7) weeks. Cortisol in umbilical cord plasma was analyzed with liquid chromatography-tandem mass spectrometry. ENaC and SGK1 mRNAs in airway epithelial cells obtained within 3 h and at 1 day postnatally were quantified with real-time PCR.

RESULTS

ENaC and SGK1 mRNAs were significantly lower in late preterm and early term infants than in those ≥ 39(0/7) weeks. Significant correlations existed between both ENaC and SGK1 and cord cortisol and GA. In term infants, SGK1 mRNA at 1.5 h was higher after vaginal delivery than elective CD.

CONCLUSIONS

In late preterm and early term infants, low expression of ENaC and SGK1 may parallel insufficient lung liquid clearance predisposing to respiratory distress. Lower SGK1 expression after term CD could translate into insufficient sodium and lung liquid absorption. The findings demonstrate a central role for cortisol in regulation of ENaC and potentially perinatal sodium and lung liquid clearance.

Neuroendocrinology of childbirth and mother-child attachment: the basis of an etiopathogenic model of perinatal neurobiological disorders

This review focuses on the neuroendocrine mechanisms in the mother and the newborn that are involved in the generation and consolidation of mother-child attachment. The role that different hormones and neurotransmitters play on the regulation of these mechanisms during parturition, the immediate postpartum period and lactation is discussed. Interferences in the initiation of mother-child attachment may have potential long-term effects for the behavior and affection of the newborn. Therefore, the possible consequences of alterations in the physiological neuroendocrine mechanisms of attachment, caused by elective Cesarean section, intrapartum hormonal manipulations, preterm delivery, mother-infant postpartum separation and bottle-feeding instead of breastfeeding are also discussed.

Lack of relationship between cord serum angiopoietin-like protein 4 (ANGPTL4) and lipolytic activity in human neonates born by spontaneous delivery

BACKGROUND

Ligands of peroxisome-proliferator activated receptors (PPARs), such as non-esterified fatty acids (NEFAs), induce expression of angiopoietin-like protein 4 (ANGPTL4). Recently ANGPTL4 has been reported to be a mediator of intracellular adipose lipolysis induced by glucocorticoids.

OBJECTIVE

To determine the concentrations of ANGPTL4 in cord serum of neonates born by spontaneous vaginal delivery (SVD) and by pre-labor cesarean section (CS) from healthy women, and to relate them to parameters of neonatal lipolytic activity at birth.

MEASUREMENTS

In 54 neonates born by SVD and in 56 neonates born by CS, arterial cord blood was drawn to determine insulin, cortisol, triacylglycerols (TAGs), glycerol, non-esterified fatty acids (NEFAs), individual fatty acids, ANGPTL4, adiponectin, retinol binding protein 4 (RBP4) and leptin.

RESULTS

Birth weight and neonatal fat mass in SVD and CS showed no difference, but the concentrations of glycerol, adiponectin, RBP4, NEFAs and most individual fatty acids were higher in cord serum of neonates born by SVD compared to CS, indicating a higher adipose tissue breakdown in the SVD group. The concentrations of TAG and cortisol were also higher and that of insulin was lower in cord serum of SVD compared to the CS group. However, the concentration in cord serum of ANGPTL4 did not differ between the two groups and no positive correlation with either NEFA or glycerol concentrations were detected.

CONCLUSION

ANGPTL4 is known to stimulate lipolysis in adults, but does not appear to mediate the increased activity in SVD, indicating the presence of different regulatory inputs.

ACTH and cortisol cord plasma concentrations in preterm and term infants

OBJECTIVE

To measure the adrenocorticotropic hormone (ACTH) and cortisol (F) cord plasma levels in preterm and term infants in relation to their mode of delivery.

STUDY DESIGN

We studied 180 newborns appropriate for gestational age (GA) with birth weights between 365 and 4380 g and GAs between 21 and 41 weeks divided into three groups: born by vaginal delivery (VD), elective cesarean section (ECS) and emergency cesarean section (EMCS). ACTH and F levels were valued with enzyme-linked immunosorbent assay testing. Median concentrations were compared between groups by Student's T-test for independent and paired data. Multiple regression analysis was used to investigate the effect of GA on F and ACTH concentrations.

RESULT

A significant positive correlation between GA and plasma concentrations of ACTH (P<0.05) was found in the whole population, but not between GA and F (P=NS). A significant positive correlation was found between GA and plasma concentrations of both ACTH (P=0.01) and F (P=0.03) in VD. In those born by ECS, we demonstrated a positive correlation not only between plasma concentrations of ACTH (P=0.0000) and F (P=0.00002), respectively, with GA, but also a correlation between ACTH and F (P=0.0004). No significant correlations were found in the EMCS group (P=NS).

CONCLUSION

Our results suggest simultaneous pituitary-adrenal maturation, which is complete only at term. The responsiveness of preterm babies to different stressful stimulations is similar to the terms' but quantitatively lower, and the secretion of ACTH and F may not suffice in severe pathological circumstances.

Ex vivo modeling of chemical synergy in prenatal kidney cystogenesis

Cyclic adenosine monophosphate (cAMP) drives genetic polycystic kidney disease (PKD) cystogenesis. Yet within certain PKD families, striking differences in disease severity exist between affected individuals, and genomic and/or environmental modifying factors have been evoked to explain these observations. We hypothesized that PKD cystogenesis is accentuated by an aberrant fetal milieu, specifically by glucocorticoids. The extent and nature of cystogenesis was assessed in explanted wild-type mouse embryonic metanephroi, using 8-Br-cAMP as a chemical to mimic genetic PKD and the glucocorticoid dexamethasone as the environmental modulator. Cysts and glomeruli were quantified by an observer blinded to culture conditions, and tubules were phenotyped using specific markers. Dexamethasone or 8-Br-cAMP applied on their own produced cysts predominantly arising in proximal tubules and descending limbs of loops of Henle. When applied together, however, dexamethasone over a wide concentration range synergized with 8-Br-cAMP to generate a more severe, glomerulocystic, phenotype; we note that prominent glomerular cysts have been reported in autosomal dominant PKD fetal kidneys. Our data support the idea that an adverse antenatal environment exacerbates renal cystogenesis.

Delayed lung liquid absorption after cesarean section at term

BACKGROUND

Delayed postnatal removal of lung liquid may result in respiratory distress, which is more common in infants born by cesarean section. Vertical artefacts (B-lines) arising from the lung surface in lung ultrasound have been shown to correlate with the liquid content of the lungs.

OBJECTIVES

We studied whether lung ultrasound could be used for the assessment of postnatal lung liquid in healthy term infants born vaginally and by cesarean section.

METHODS

Lung ultrasound was performed 1, 3 and 24 h after birth to 22 vaginally born infants and 20 infants born by elective cesarean section. The abundance of B-lines was scored for each infant and time point by two independent observers blinded to the mode of delivery and time point on the examination on a five-step scale.

RESULTS

In both groups, a significant decrease in abundance of B-lines, indicative of lung liquid absorption, was observed during the first 24 h. 3 h after birth cesarean section was associated with significantly higher lung liquid content than vaginal delivery.

CONCLUSION

The noninvasive bedside ultrasound method for estimation of lung liquid is a promising tool for the early identification of infants at risk for pulmonary maladaptation.

Stress and pain response of neonates after spontaneous birth and vacuum-assisted and cesarean delivery

OBJECTIVE

The objective of the study was to compare the stress response and pain expression of newborns (NBs) in the early postpartum period.

STUDY DESIGN

This was a prospective study with 280 NBs enclosed at 3 Swiss university hospitals. Stress response and pain reaction were analyzed according to the mode of delivery: elective cesarean section (ELCS), spontaneous vaginal delivery, and assisted vaginal delivery by vacuum extraction (VE). Saliva cortisol and clinical pain expression were evaluated after delivery and before and after heel prick for metabolic screening.

RESULTS

Significant differences were evident during the first 72 hours postpartum with highest nominations in the VE group. Meconium-stained amniotic fluid was the only intrapartum stress factor with an impact on clinical pain expression.

CONCLUSION

NBs delivered vaginally show a higher incidence of stress response and pain expression than infants of the ELCS group. The long-term impact of these findings remains to be determined.

The effect of mode of delivery on T regulatory (Treg) cells of cord blood

OBJECTIVE

To evaluate whether the mode of delivery (vaginal versus C-section) influences the levels of CD4+CD25+FOXP3+ Treg cells in cord blood and maternal peripheral blood and also to examine its relationship with plasma cortisol levels.

METHODS

Newborns either born vaginally (n = 19) or via elective C- section (n = 20) and their mothers, as well as 20 healthy but not pregnant women, were included in the study. CD4+CD25+FOXP3 (Treg) cells were examined by flow cytometry. Total lymphocyte counts (TLC) and serum cortisol levels were also determined for all the groups.

RESULTS

The percentages of CD4+CD25+FOXP3 cells and the serum cortisol levels of infants born vaginally (p < 0.004 and p < 0.0001) and their mothers (p < 0.0001 for both) were found to be significantly higher than those of newborns born by C-section and their mothers. Positive correlations were seen between CD4+CD25+FOXP3+ cells (r = 0.741) and serum cortisol levels (r = 0.468). No relationship was observed between newborns delivered by C-section and their mothers (r = 0.022 for both).

CONCLUSIONS

This study suggests that mode of delivery affects cord blood Treg cells. Higher CD4+CD25+FOXP3+ Treg cells of newborns and their mothers in vaginal delivery group and their relationship with serum cortisol levels suggest a stress phenomenon related to vaginal delivery.

The health implications of birth by Caesarean section

Since the first mention of fetal programming of adult health and disease, a plethora of programming events in early life has been suggested. These have included intrauterine and postnatal events, but limited attention has been given to the potential contribution of the birth process to normal physiology and long-term health. Over the last 30 years a growing number of studies have demonstrated that babies born at term by vaginal delivery (VD) have significantly different physiology at birth to those born by Caesarean section (CS), particularly when there has been no exposure to labour, i.e. pre-labour CS (PLCS). This literature is reviewed here and the processes involved in VD that might programme post-natal development are discussed. Some of the effects of CS are short term, but longer term problems are also apparent. We suggest that VD initiates important physiological trajectories and the absence of this stimulus in CS has implications for adult health. There are a number of factors that might plausibly contribute to this programming, one of which is the hormonal surge or "stress response" of VD. Given the increasing incidence of elective PLCS, an understanding of the effects of VD on normal development is crucial.