Preterm Boys Research Articles

The epidemiology of cryptorchidism and potential risk factors, including endocrine disrupting chemicals.

Congenital cryptorchidism, also known as undescended testis, is the condition where one or both testes are not in place in the scrotum at birth and is one of the most common birth defects in boys. Temporal trends and geographic variation in the prevalence of cryptorchidism from 1% to 9% have been reported in prospective cohort studies. The testes develop in the abdominal cavity and descend to the scrotum in two phases, which should be completed by gestational week 35. Thus, the risk of cryptorchidism is higher in preterm boys. In many cases a spontaneous descent occurs during the first months of life during the surge of gonadotropins and testosterone. If not, the testis is usually brought down to the scrotum, typically by surgery, to increase future fertility chances and facilitate cancer surveillance. The increasing frequency of impaired semen quality and testicular cancer, with which cryptorchidism is associated, represents a concern for male reproductive health in general and a need to understand its risk factors. The risk of cryptorchidism is closely related to gestational factors (preterm birth, low birth weight and intrauterine growth restriction), and especially maternal smoking seems to be a risk factor. Evidence is accumulating that the increasing prevalence of cryptorchidism is also related to prenatal exposure to environmental chemicals, including endocrine disrupting compounds. This association has been corroborated in rodents and supported by ecological studies. Conducting human studies to assess the effect of endocrine disrupting chemicals and their interactions is, however, challenged by the widespread concomitant exposure of all humans to a wide range of chemicals, the combined effect of which and their interactions are highly complex.

Minipuberty in Male Full-term Neonates Appropriate and Small for Gestational Age and in Preterm Babies: Data from a Single Centre

The postnatal activation of the hypothalamic-pituitary-gonadal (HPG) axis is usually known as “minipuberty”. There are still open questions about its biological function and significance depending on sex, gestational age (GA) and birth weight (BW) with few available longitudinal data. A single-centre, longitudinal study to quantify urinary follicle stimulating hormone (uFSH), luteinizing hormone (uLH) and testosterone (uTs) in male neonates. Neonates were enrolled and stratified into three subgroups: full-term boys appropriate for GA (FT AGA); FT boys with BW ≤3rd centile [FT small for gestational age (SGA)]; and preterm (PT) boys ≤33 weeks of GA. Urinary hormones were correlated to simultaneous auxological parameters, linear growth and external genitalia at scheduled time-points. Forty-six boys were recruited, with subgroup sizes FT AGA n=23, FT SGA n=11 and PT n=12. PT boys display a pulsatile pattern of urinary gonadotropins (uGns) with higher levels of uLH and a gradual increase of uTs. Testicular descent started from 29-32 weeks with the peak of uTs. During the first 12-months post-term age (PTA), FT AGA boys displayed a better linear growth (p<0.05). PT showed higher uGns levels until 3-months PTA. PT babies had higher uLH levels than FT AGA, with a peak at 7 and 30 days, during the first 90 days of life (p<0.001) and higher uTs levels. Correlation analysis between penile growth of all neonates and uTs was significant (p=0.04) but not within subgroups. This study investigated postnatal HPG axis activation in term and PT infants. Minipuberty may involve an early window of opportunity to evaluate the functionality of the HPG axis. Further studies with a long-term follow-up are needed with a special focus on possible consequences of GA and BW.

Pre- and peripubertal sex steroids are inversely associated with birth weight in preterm boys.

The relationship between sex hormone concentrations during childhood and birth weight (BW) is poorly understood. We aimed to investigate this relationship and the associations with anthropometric data at 5, 6, 7, 8, and 10 years of age in preterm boys. A prospective longitudinal single-centre study, including 58 boys with a BW of 1325-3320 gand gestational age (GA) of 32 + 2 to 36 + 6 weeks. Data on GA, BWand anthropometric data between 5 and 10 years of age were recorded. Testicular development was assessed at 8 and 10 years of age. Serum concentrations of sex steroids were analysed with gas chromatography-tandemmass spectrometry at 5-10 years and luteinizing hormone (LH) and follicle-stimulating hormone (FSH) with immunoassays at 10 years of age. At 8 years of age, testosterone and estrone correlated negatively with BW, (ρ = -0.35, p = .021) and (ρ = -0.34, p = .024), respectively. At 10 years of age, testosterone, dihydrotestosterone, estroneand estradiol correlated negatively with BW (ρ = -0.39, p = .010), (ρ = -0.38, p = .013), (ρ = -0.44, p = .003)and (ρ = -0.36, p = .019), respectively. Weight gain from birth correlated with testosterone at 5 years (ρ = 0.40, p = .002), 7 years (ρ = 0.30, p = .040), 8 years (ρ = 0.44, p = .003)and 10 years (ρ = 0.40, p = .008) of age. At 10 years of age, testosterone correlated with LH (ρ = 0.42, p = .006) and FSH (ρ = 0.33, p = .033) but not with testicular volume. Lower BW was associated with increased sex steroid concentrations from 8 years of age, independently of clinical signs of puberty.

Longitudinal Sex Steroid Data in Relation to Birth Weight in Preterm Boys.

There is a lack of knowledge on longitudinal sex steroid patterns during infancy, especially for boys born preterm or with low birth weight (LBW). To find out whether LBW boys have a disturbed sex steroid profile during infancy. Population-based longitudinal study performed at Sahlgrenska University Hospital, Gothenburg, Sweden. Ninety-eight singleton boys (47 LBW) born at gestational age 32.0 to 36.9 weeks were included. Because of dropout, 83 of the boys were still in the study at 10 months' corrected age. Serum androgen and estrogen concentrations were analyzed by gas chromatography-tandem mass spectrometry and IGF-I was determined with radioimmunoassay in umbilical cord and at 0, 2, 5, and 10 months' corrected age. Serum levels of androstenedione, estrone, and estradiol declined gradually from birth to 10 months corrected age. In both LBW boys and their counterparts, a surge was seen at 2 months' corrected age (3 months' chronological age) for testosterone, median (range) 6.5 (2.0-18.9) nmol/L, and in dihydrotestosterone 1.2 (0.4-4.3) nmol/L. At birth, LBW boys had higher median testosterone (0.7 vs 0.4 nmol/L, P = 0.019), and at 0 months' corrected age, both had higher testosterone (5.7 vs 3.5 nmol/L, P = 0.003) and dihydrotestosterone (1.2 vs 0.9 nmol/L, P = 0.006) than their counterparts. At 10 months' corrected age, catch-up in weight SD score from birth correlated with testosterone (rho = 0.27, P = 0.044) and androstenedione (rho = 0.29, P = 0.027). Moderately to late preterm LBW boys showed a disturbed sex hormone profile, with elevated concentrations of androgens in early infancy.

Sex Differences in Patent Ductus Arteriosus Incidence and Response to Pharmacological Treatment in Preterm Infants: A Systematic Review, Meta-Analysis and Meta-Regression.

A widely accepted concept in perinatal medicine is that boys are more susceptible than girls to complications of prematurity. However, whether this ‘male disadvantage of prematurity’ also involves persistent patent ductus arteriosus (PDA) has been scarcely investigated. Our aim was to conduct a systematic review and meta-analysis on studies addressing sex differences in the risk of developing PDA among preterm infants. We also investigated whether the response to pharmacological treatment of PDA differs between boys and girls. PubMed/Medline and Embase databases were searched. The random-effects male/female risk ratio (RR) and 95% confidence interval (CI) were calculated. We included 146 studies (357,781 infants). Meta-analysis could not demonstrate sex differences in risk of developing any PDA (37 studies, RR 1.03, 95% CI 0.97 to 1.08), hemodynamically significant PDA (81 studies, RR 1.00, 95% CI 0.97 to 1.02), or in the rate of response to pharmacological treatment (45 studies, RR 1.01, 95% CI 0.98 to 1.04). Subgroup analysis and meta-regression showed that the absence of sex differences was maintained over the years and in different geographic settings. In conclusion, both the incidence of PDA in preterm infants and the response rate to pharmacological treatment of PDA are not different between preterm boys and girls.

Prevalence of congenital cryptorchidism in Estonia.

Cryptorchidism is one of the most common urogenital malformations. Cryptorchidism prevalence varies greatly in different countries and populations. The aim of the current study was to determine and analyse cryptorchidism prevalence in Estonia. During 2012-2015, all consecutively born 5014 boys at Tartu University Hospital were examined for cryptorchidism. All the subjects with cryptorchidism were followed up for at least 6 months to assess spontaneous testicular descent. Note that 2.1% cases had one or both testicles undescended at birth, 1.6% cases at expected date of birth, 1% cases at 3 months of age, and 0.8% cases at the age of 6 months had cryptorchidism. Cryptorchidism prevalence at birth was higher in preterm boys (11.9%), boys of low birth weight (16.7%) and boys small for gestational age (14%) but was lower in full-term newborn boys (1.1%). During follow-up, testes descended spontaneously in 61.6% of boys, more commonly in prematurely born boys (92%) and boys with low gestational weight (93%) as compared to full-term cryptorchid boys (29.2%) and cryptorchid boys with normal birth weight (34%). At the age of 6 months, cryptorchidism prevalence was equalized in preterm boys (0.9%) and boys with low birth weight (1%) as compared to full-term boys (0.7%) and boys with normal birth weight (0.7%). Boys SGA required surgical intervention more commonly than boys with normal birth weight. Ethnically, cryptorchidism prevalence at birth was similar among Estonians and non-Estonians. Our data revealed that cryptorchidism prevalence, especially in full-term boys, is lower in Estonia than reported in the other Nordic-Baltic countries and worldwide.

The Quality of Interactive Behaviors in the Context of Prematurity: Fathers, Mothers, Daughters, and Sons.

This study examined the quality of interaction between preterm-born preschoolers and their mothers and fathers, focusing on the role of child and parental sex. Participants included 88 preterm-born children (<37 wk gestational age) and 44 full-term-born children (≥37 wk gestational age) aged 3 1/2 years and their parents. Mother-child and father-child dyads were observed during a structured interactive task. Children's cooperation-compliance and negativity-hostility behaviors were coded using the Coding System for Mother-Child Interactions, and parents' sensitive behavior was coded using the Ainsworth Sensitivity Scale. There was no association between preterm birth and the quality of child and parents' interactive behaviors. In the full-term group, fathers exhibited lower levels of sensitive behavior than mothers, but in the preterm group, both parents exhibited similar levels of sensitive behavior. Preterm boys exhibited more interactive difficulties than preterm girls, but there was no significant effect of child sex on full-term children's interactive behaviors. Children exhibited more compliance-cooperation and less negativity-hostility toward fathers than toward mothers. The findings suggest that prematurity in itself does not affect the quality of parent-preterm child interactive behaviors as the children enter the preschool period. Preterm boys seem to be at higher risk for interactive difficulties than girls, and thus, child sex should be considered when monitoring and examining the development of preterm children.

Male Disadvantage in Oxidative Stress-Associated Complications of Prematurity: A Systematic Review, Meta-Analysis and Meta-Regression.

A widely accepted concept is that boys are more susceptible than girls to oxidative stress-related complications of prematurity, including bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), and periventricular leukomalacia (PVL). We aimed to quantify the effect size of this male disadvantage by performing a systematic review and meta-analysis of cohort studies exploring the association between sex and complications of prematurity. Risk ratios (RRs) and 95% CIs were calculated by a random-effects model. Of 1365 potentially relevant studies, 41 met the inclusion criteria (625,680 infants). Male sex was associated with decreased risk of hypertensive disorders of pregnancy, fetal distress, and C-section, but increased risk of low Apgar score, intubation at birth, respiratory distress, surfactant use, pneumothorax, postnatal steroids, late onset sepsis, any NEC, NEC > stage 1 (RR 1.12, CI 1.06–1.18), any IVH, severe IVH (RR 1.28, CI 1.22–1.34), severe IVH or PVL, any BPD, moderate/severe BPD (RR 1.23, CI 1.18–1.27), severe ROP (RR 1.14, CI 1.07–1.22), and mortality (RR 1.23, CI 1.16–1.30). In conclusion, preterm boys have higher clinical instability and greater need for invasive interventions than preterm girls. This leads to a male disadvantage in mortality and short-term complications of prematurity.

Real world research on the growth pattern of preterm children with different birth weight

Objective: To investigate the physical indices and growth status of preterm children aged 0 to 4 years with different birth weight. Methods: Following the real world research approach, the current study retrospectively collected e-chart information of 8 496 preterm children from the child health care system of the Children's Hospital of Chongqing Medical University from December 2010 to December 2017, with 203 123 full-term children followed up during the same period as controls. Premature children were divided into normal birth weight (NBW) group, low birth weight (LBW) group, and very low birth weight (VLBW) group based on their birth weights. The weight and length development within 48 months of age of preterm boys and girls in each group were measured and recorded to establish a numerical table and analyze the growth levels, growth rate, and proportionality. The t-test or chi-square test was used for between-group comparison. Results: Of the 8 496 preterm children, 4 839 were girls and 3 657 boys, including 525 in the VLBW group, with an average birth weight of (1.28±0.14) kg, 3 862 in the LBW group, with an average birth weight of (2.07±0.28) kg, and 4 109 in the NBW group, with an average birth weight of (2.86±0.35) kg. The weight at the actual age of 2-<3 months ((5.61±0.96) vs. (5.64±0.78) kg in boys, (5.11±0.67) vs. (5.18±0.71) kg in girls) and the length at the actual age of 8-<10 months ((70.3±2.4) vs. (70.6±2.4) cm in boys, (68.9±2.2) vs. (68.9±2.4) cm in girls) in the NBW group reached the average weight and length of full-term children. The difference of physical growth before 24 months of age between LBW and control group decreased as children age, with that of LBW group approaches the average of full-term children after 24 months of age, with a weight difference of 0.64-0.95 kg and height difference of 1.3-1.7 cm. The weight and height of the VLBW group were lower than those of full-term infants (2.80-2.86 kg and 3.3-4.3 cm, respectively) at 48 months of age. During 2-12 months of age, the corresponding values of the VLBW group were higher than that of the LBW and NBW groups by 0.35 kg and 0.71 kg, respectively. However, the corresponding values of the VLBW group were lower than that of the LBW and NBW groups(0.64 kg and 0.76 kg at 0-2 months of age, 1.04 kg and 1.49 kg at 12-48 months of age, respectively). The rates of delayed development, underweight, and emaciation were the highest in the VLBW group (all P<0.01), while the rates of overweight and obesity were the highest in the NBW group, with that of the VLBW group being lower than LBW group (P<0.01) at the age of 24-<36 months. Conclusions: Prior to 4 years of age, the time for preterm children to reach the average physical indices of full-term children differ by birth weights, hence warranting further examination of the corrected gestational age for preterm children. Normal birth weight preterm children present with the highest incidence of overweight and obesity and very low birth weight preterm children present with the highest incidence of growth disorders, marking both groups at high risks of malnutrition.

Adrenal androgen trajectories are established during childhood in preterm boys.

We investigated longitudinal adrenal androgen concentrations and any relationship between gestational age, birth size, anthropometric parameters and adrenal androgen concentrations during childhood in boys born moderate to late preterm. This longitudinal, prospective study included 58 boys born at 32+0 to 36+6weeks of gestation. Dehydroepiandrosterone sulphate and androstenedione were analysed by liquid chromatography-tandem mass spectrometry, and anthropometric data were recorded from 5 to 10years of age. Dehydroepiandrosterone sulphate concentrations correlated with weight standard deviations scores (SDS) from 7 to 10years of age and waist-to-height ratios at seven and 10years of age. Androstenedione correlated with weight SDS from 7 to 10years of age and waist-to-height ratios at 10years of age. Longitudinal analysis showed a relationship between weight SDS and waist-to-height SDS and dehydroepiandrosterone sulphate (p<0.001 and p<0.001, respectively) and androstenedione (p=0.002 and p=0.003, respectively), independently of age. The trajectories of anthropometric parameters and adrenal androgen secretion were consistent from 5 to 10years of age in this cohort. The body composition reflected by current weight and the waist-to-height ratio, rather than gestational age and birth size, was associated with adrenal androgen secretion.

Anatomical location of undescended testes and comparison between their size at different anatomical locations: A cross sectional study

Introduction: Undescended testis (UDT) or cryptorchidism is a common childhood condition in which a boy is born without having one or both testes in their scrotum. It is a very frequent clinical finding in boys, with a prevalence of about 2-4%. The inguinoscrotal phase of testicular descent normally takes place in the last trimester of pregnancy. The regulation of prenatal testicular descent in humans is not fully understood, but numerous genetic and endocrinal factors are thought to have been involved. Preterm boys have been described to have a higher rate of UDT. The classification of UDT is performed according to palpable or nonpalpable testis. If the testis is located inside the normal path of descent, the testis is called ’intra-abdominal’, for those located in the abdomen is called ’intracanalicular’, for those located between the internal and external rings or ’suprascrotal’, for those located between the entrance of the scrotum and the external ring. This study was conducted to determine the frequency of anatomical location of undescended testis in pediatric patients undergoing orchidopexy as well as to compare the mean size of undescended testis at different anatomical location in pediatric patients undergoing orchidopexy as a secondary objective. Methods: It’s a cross sectional study of 94 patients with total 110 testes as per inclusion criteria. Study was performed at pediatric surgery department of Liaquat National university hospital Karachi, Pakistan for a duration of eight months. Orchidopexy was performed under general anesthesia as a surgical day care procedure. At orchiopexy, the outcome variables i.e. location and size of the testis was noted. The size of the testis was measured in anteroposterior and mediolateral dimensions vernier caliper, graduated in mm. The size of testis was calculated by modified Lambert’s formula (0.71xlengthxwidth2). All the collected data were entered into the proforma attached at the end. Results: Mean±SD of age was 4.29±2.19 with C.I (3.38…….4.74) years. Mean±SD of size of testis was 425.68±244.43 with C.I. (375.89……..475.47) mm. In location of testis 4 (4.2%) was located at intra-abdominal, 15 (16%) at intracanalicular and 75 (79.8%) was located at distal to superficial ring. Mean size of testis in intra-abdominal location was 276.29±145.47, intra-canalicular 367.89±196.15, distal to superficial ring was 442.27±54.08 and non-significant P-value was found i.e. (p=0.264). Conclusion: No significant difference was found between mean size of testis and location of undescended testis. The most common location was distal to superficial ring. Keyword: Testes; Undescended; Anatomical Location; Orchidopexy; Anatomical Location

The role of makorin ring finger protein-3, kisspeptin, and neurokinin B in the physiology of minipuberty.

There is no data regarding the interrelationships of circulating Makorin Ring Finger Protein-3 (MKRN3), Kisspeptin (KISS1), and Neurokinin B (NKB) concentrations during minipuberty in humans. To determine temporal changes in circulating concentrations of MKRN3, KISS1, NKB, and gonadotropins and investigate interrelationships between them in healthy full-term (FT) and preterm (PT) infants during minipuberty period. A prospective study of 6-month follow-up performed. Eighty-seven healthy newborns, 48 FT (19 boys/29 girls), and 39PT (21 boys/18 girls) (gestational age 31-37weeks), were included. Blood samples were taken at 7days (D7), 2months (M2), and 6months (M6) of age. Serum MKRN3, KISS1, NKB, LH, FSH, total testosterone (TT), and estradiol (E2) concentrations were measured. Seventy infants completed the study. MKRN3, KISS1, and NKB concentrations were similar in FT girls and boys. PT boys and girls also had similar concentrations of MKRN3, KISS1, and NKB. FT babies had significantly higher NKB concentrations than PT babies at D7, M2, and M6. MKRN3 and KISS1 concentrations do not differ between FT and PT babies. A strong positive correlation was found between MKRN3 and KISS1 at each time point and in all groups. FSH, LH, TT/E2 concentrations decrease while those of MKRN3 and KISS1 have a trend to increase toward the end of minipuberty. No correlation was detected between gonadotropins and MKRN3, KISS1, NKB concentrations. Strong positive correlation demonstrated between KISS1 and MKRN3 suggests that interrelationship between molecules controlling minipuberty is not similar to those at puberty.

Do preterm girls need different nutrition to preterm boys? Sex-specific nutrition for the preterm infant.

Boys born preterm are recognised to be at higher risk of adverse outcomes than girls born preterm. Despite advances in neonatal intensive care and overall improvements in neonatal morbidity and mortality, boys born preterm continue to show worse short- and long-term outcomes than girls. Preterm birth presents a nutritional crisis during a critical developmental period, with postnatal undernutrition and growth-faltering common complications of neonatal intensive care. Furthermore, this preterm period corresponds to that of rapid in utero brain growth and development, and the developmental window relating to foetal programming of adult non-communicable diseases, the prevalence of which are associated both with preterm birth and sex. There is increasing evidence to show that from foetal life, boys and girls have different responses to maternal nutrition, that maternal breastmilk composition differs based on foetal sex and that early neonatal nutritional interventions affect boys and girls differently. This narrative review examines the evidence that sex is an important moderator of the outcomes of preterm nutrition intervention, and describes what further knowledge is required before providing nutrition intervention for infants born preterm based on their sex. IMPACT: This review examines the increasing evidence that boys and girls respond differently to nutritional stressors before birth, that maternal breastmilk composition differs by foetal sex and that nutritional interventions have different responses based on infant sex. Boys and girls born preterm are given standard nutritional support which does not take infant sex into account, and few studies of neonatal nutrition consider infant sex as a potential mediator of outcomes. By optimising early nutrition for boys and girls born preterm, we may improve outcomes for both sexes. We propose future studies of neonatal nutritional interventions should consider infant sex.

Comparison of Blood Pressure and Kidney Markers between Adolescent Former Preterm Infants and Term Controls.

Background: Preterm infants are at an increased risk of developing hypertension and chronic kidney disease later in life. No recommendations exist for blood pressure (BP) and renal follow up for these patients. Aim: To compare BP and serum and urinary kidney markers between preterm-born adolescents and term-born controls. Methods: BP measurements in 51 preterm-born (≤32 weeks gestational age) and 82 term-born adolescents at the age of 10–15 years were conducted. Stepwise regression analysis explored the association between BP and participant characteristics. Kidney markers measured in the serum and urine were creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and uromodulin. Kidney markers measured in the serum were cystatin C, beta-2 microglobulin, and beta trace protein. Results: Systolic BP was significantly higher in preterm boys compared with term boys, but not in girls, and low birth weight was associated with higher BP in boys. In the preterm group, maternal hypertension/preeclampsia and adolescent height were associated with higher systolic BP. Serum creatinine and NGAL were significantly higher in the preterm group. Conclusions: Our study confirms an inverse sex-dependant relationship between birth weight and BP at adolescent age. The higher serum creatinine and NGAL in the preterm group may indicate that premature birth affects kidney function in the long term.

Language skills at corrected age 2;0 are poorer in extremely and very preterm boys but not girls compared with their full-term peers

PurposeTo date, there are contradictory findings concerning if, at which age, and to what extent children's language development is affected by prematurity at birth.The objective was to compare language skills of extremely preterm (EPT) and very preterm (VPT) girls and boys at 24 months corrected for gestational age (GA) at birth with those of full-term (FT) girls and boys, and to explore the effect of perinatal and demographic factors. MethodParents of 138 preterm (PT) children born <32 weeks' gestation (48 EPT with GA below 28 weeks, 90 VPT with GA 28–31 weeks) and of 150 FT controls completed the short Estonian version of the MacArthur-Bates Communicative Development Inventory: Words and Sentences (ECDI-II SF). Language skills of PT children were also assessed with the Bayley-III Language Scale (BSID-III), and compared with data from 152 FT controls. ResultsMean scores of all language measurements were significantly lower in boys (not girls) from both PT groups compared to FT girls and boys, while no significant differences were found between PT groups. Across groups, girls obtained significantly better language scores than boys. In PT children, being a girl, and attending day care at corrected age (CA) 2;0 years, predicted a larger expressive vocabulary (measured by the ECDI-II SF). Bayley language composite scores (sum of expressive and receptive language) were higher in PT girls than in boys, and the scores were negatively affected by the number of severe neonatal morbidities. ConclusionsThe findings highlight the importance of systematic language-focused assessments (using parents and trained examiners) of EPT and VPT boys, as well as the need to support their development.

Trends in sex-specific differences in outcomes in extreme preterms: progress or natural barriers?

ObjectiveTo examine the differences and trends of outcomes of preterm boys and girls born at <29 weeks’ gestation.DesignA retrospective cohort study.SettingData collected by the Canadian Neonatal Network.PatientsNeonates born at <29...

Neonatal cortical perceptions of maternal breast odours: A fNIRS study.

The aim was to determine whether preterm and full-term newborn infants could process maternal breast odour at a cortical level. Newborn infants were exposed to cloths containing their own mother's breast odour and freshly laundered control cloths for 10seconds, while functional near-infrared spectroscopy measured cortical activation in their olfactory processing areas. We studied 45 newborn infants born at 28-41weeks of gestation and divided them into three groups: full-term (37-41weeks), late preterm (33-36weeks) and very preterm (28-32weeks). Cortical activation was defined as a regional increase of oxyhaemoglobin following maternal breast odour stimuli. Full-term infants demonstrated bilateral activation of their olfactory cortices following exposure to maternal breast odour. Late preterm infants and very preterm boys exhibited unilateral cortical activation, unlike very preterm girls. Infants born from 32weeks, and possibly earlier, could process low concentration maternal odours at a cortical level, which suggests they were more aware of their environment. These findings could make a significant contribution to improving the sensory environment of preterm infants and improve bonding.

Sex differences in brain connectivity and male vulnerability in very preterm children.

Evidence indicates better cognitive and behavioral outcomes for females born very preterm (≤32 weeks gestation) compared to males, but the neurophysiology underlying this apparent resiliency of the female brain remains poorly understood. Here we test the hypothesis that very preterm males express more pronounced connectivity alterations as a reflection of higher male vulnerability. Resting state MEG recordings, neonatal and psychometric data were collected from 100 children at age 8 years: very preterm boys (n = 27), very preterm girls (n = 34), full‐term boys (n = 15) and full‐term girls (n = 24). Neuromagnetic source dynamics were reconstructed from 76 cortical brain regions. Functional connectivity was estimated using inter‐regional phase‐synchronization. We performed a series of multivariate analyses to test for differences across groups as well as to explore relationships between deviations in functional connectivity and psychometric scores and neonatal factors for very preterm children. Very preterm boys displayed significantly higher (p < .001) absolute deviation from average connectivity of same‐sex full‐term group, compared to very preterm girls versus full‐term girls. In the connectivity comparison between very preterm and full‐term groups separately for boys and girls, significant group differences (p < .05) were observed for boys, but not girls. Sex differences in connectivity (p < .01) were observed in very preterm children but not in full‐term groups. Our findings indicate that very preterm boys have greater alterations in resting neurophysiological network communication than girls. Such uneven brain communication disruption in very preterm boys and girls suggests that stronger connectivity alterations might contribute to male vulnerability in long‐term behavioral and cognitive outcome.

Identificación de problemas de conducta y emocionales en niños prematuros en el ámbito de atención primaria

ObjectiveTo demonstrate the usefulness, for use by the primary care pediatrician, of the BASC questionnaire (Behavior Assessment System for Children) for the early detection of psychological and behavioral problems in premature infants. DesignCross-sectional and descriptive study. SettingPrimary care (Health Area IV of the Principado of Asturias) and Hospital Universitario Central de Asturias, Spain. ParticipantsParents of 87 premature children with birth weight less than 1500g and 43 full-term controls, both aged 5-7 years. Main measurementsThe BASC questionnaire (parent version) was applied. ResultsPreterm children presented a high rate of inactivity (Z = −4.125, P < 0.001), anxiety (Z = −2.801, P = 0.005) and internalization problems (Z = −2.148, P = 0.032), being more evident at 5 years of age. Preterm boys show higher levels of hyperactivity (Z = −2.082, P = 0.037) and behavioural problems (Z = −2.354, P = 0.019) than girls, who presented more attentional problems (Z = −2.345; P = 0.019). ConclusionsThe BASC questionnaire is useful for the detection and early diagnosis at the primary care level of the behavioral and emotional problems of premature children.

Simple Categorization of Human Figure Drawings at 5 Years of Age as an Indicator of Developmental Delay

ABSTRACTPurpose: To elucidate the association between developmental stage of human figure drawing(HFD) and fine motor control, visual perception, and further investigate its potential to be used for screening developmental delay.Methods: Participants were 301 children at 5½ years of age, 176 born preterm and 125 at term, whose HFDs were categorized into six developmental stages. Motor-Free-Visual-Perception Test, Movement-ABC, Performance Intelligence Quotient (PIQ: Wechsler Scale), and the Visual-Motor Integration test were used. Fine motor functions were explored using ImageJ.Results: Age-expected HFDs were drawn by 87% of the children, while 13%, mostly preterm boys, drew immature ones. Stages of HFD were related to both PIQ and Movement-ABC. Visuomotor control and visual perception significantly explained the HFD. The sensitivity and specificity of HFD as a screening tool was moderate to good.Conclusions: HFD is influenced by visual perception and visuomotor control and can be used for screening developmental delay at preschool age.