Differences in Factors Associated With Preterm and Term Stillbirth: A Secondary Cohort Analysis of the DESiGN Trial.

OBJECTIVE: To identify whether maternal and pregnancy characteristics associated with stillbirth differ between preterm and term stillbirth. DESIGN: Secondary cohort analysis of the DESiGN RCT. SETTING: Thirteen UK maternity units. POPULATION: Singleton pregnant women and their babies. METHODS: Multiple logistic regression was used to assess whether the 12 factors explored were associated with stillbirth. Interaction tests assessed for a difference in these associations between the preterm and term periods. MAIN OUTCOME MEASURE: Stillbirth stratified by preterm (<37+0 weeks') and term (37+0-42+6 weeks') births. RESULTS: A total of 195 344 pregnancies were included. Six hundred and sixty-seven were stillborn (3.4 per 1000 births), of which 431 (65%) were preterm. Significant interactions were observed for maternal age, ethnicity, IMD, BMI, parity, smoking, PAPP-A, gestational hypertension, pre-eclampsia and gestational diabetes but not for chronic hypertension and pre-existing diabetes. Stronger associations with term stillbirth were observed in women with obesity compared to BMI 18.5-24.9 kg/m2 (BMI 30.0-34.9 kg/m2 term adjusted OR 2.1 [95% CI 1.4-3.0] vs. preterm aOR 1.1 [0.8-1.7]; BMI ≥ 35.0 kg/m2 term aOR 2.2 [1.4-3.4] vs. preterm aOR 1.5 [1.2-1.8]; p-interaction < 0.01), nulliparity compared to parity 1 (term aOR 1.7 [1.1-2.7] vs. preterm aOR 1.2 [0.9-1.6]; p-interaction < 0.01) and Asian ethnicity compared with White (p-interaction < 0.01). A weaker or lack of association with term, compared to preterm, stillbirth was observed for older maternal age, smoking and pre-eclampsia. CONCLUSION: Differences in association exist between mothers experiencing preterm and term stillbirth. These differences could contribute to design of timely surveillance and interventions to further mitigate the risk of stillbirth.

A nationwide birth cohort in Japan showed increased risk of early childhood hospitalisation in infants born small for gestational age.

AIM: To examine associations between children being born small for gestational age and childhood hospitalisation following term and preterm births. METHODS: This study included 34 564 children from a nationwide population-based longitudinal survey starting in 2010, comprising 32 603 term births and 1961 preterm births. Children's hospitalisation history was examined during two observational periods, 6-18 and 6-66 months of age. Logistic regression analysis was conducted, adjusting for child and parental confounders, with children born appropriate for gestational age as reference. RESULTS: Children born small for gestational age were more likely to be hospitalised during early childhood than those born appropriate for gestational age. The odds ratio (95% confidence interval) for hospitalisation from 6 to 66 months of age was 1.19 (1.05-1.34) in term children born small for gestational age and 1.47 (1.05-2.06) for preterm children born small for gestational age, compared with those born appropriate for gestational age. The risk of hospitalisation from 6 to 66 months of age in children born small for gestational age was observed for bronchitis/pneumonia. CONCLUSION: We observed the adverse effects of small for gestational age on hospitalisation during early childhood in both term and preterm births, particularly for bronchitis and pneumonia.

Evaluation of possible associated factors for early childhood caries: are preterm birth and birth weight related?

BACKGROUND: This study aimed to evaluate the oral and dental health of preschool children aged 12-71 months living in the Eastern Anatolia Region of Turkey, and to examine the effects of low birth weight (LBW) and preterm, early term and term birth on dental caries. METHODS: 475 participants were included in the study. Intraoral examinations were performed and evaluated for the presence of early childhood caries (ECC). These values ​​are; Relationships such as age, gender, birth weight, week of birth, tooth brushing frequency, cariogenic nutrition, and parental education levels were examined. The obtained data were analyzed statistically (chi-square, t-test, artificial neural network (ANN)). RESULTS: Of the 475 participants, whose parents agreed to fill out the questionnaire, 250 were female and 225 were male. While the mean age was 49.78 ± 14.78 months for those with ECC, it was 38.93 ± 17.96 months for those without. Higher duration of breastfeeding (p = 0.04), education level of parents (p = 0.001), lower socioeconomic level (p = 0.001), and lower brushing frequency (p = 0.001) were also found to be significantly associated with ECC. ECC was seen in 90% of 77 children with a history of preterm birth. In LBW, this rate was 83%. According to the ANN result, in preterm birth; 12.9% affected ECC by LBW. CONCLUSION: According to the results of our study, both LBW and preterm delivery were found to be associated with ECC and S-ECC (severe early childhood caries). An additional study on parents of preterm/LBW infants would be beneficial. In the early period, regular dental examination, implementation of preventive and preventive treatments, and nutrition education to parents can make a significant difference in the prevention of ECC.

Extracellular vesicles as markers and mediators of pregnancy complications: gestational diabetes, pre-eclampsia, preterm birth and fetal growth restriction.

In high income countries, approximately 10% of pregnancies are complicated by pre-eclampsia (PE), preterm birth (PTB), fetal growth restriction (FGR) and/or macrosomia resulting from gestational diabetes (GDM). Despite the burden of disease this places on pregnant people and their newborns, there are still few, if any, effective ways of preventing or treating these conditions. There are also gaps in our understanding of the underlying pathophysiologies and our ability to predict which mothers will be affected. The placenta plays a crucial role in pregnancy, and alterations in placental structure and function have been implicated in all of these conditions. As extracellular vesicles (EVs) have emerged as important molecules in cell-to-cell communication in health and disease, recent research involving maternal- and placental-derived EV has demonstrated their potential as predictive and diagnostic biomarkers of obstetric disorders.  This review will consider how placental and maternal EVs have been investigated in pregnancies complicated by PE, PTB, FGR and GDM and aims to highlight areas where further research is required to enhance the management and eventual treatment of these pathologies.

Birth Weight in Consecutive Pregnancies and Maternal Cardiovascular Disease Mortality Among Spontaneous and Iatrogenic Term Births: A Population-Based Cohort Study.

Knowledge on the association between offspring birth weight and long-term risk of maternal cardiovascular disease (CVD) mortality is often based on firstborn infants without consideration of women's consecutive births. We studied long-term CVD mortality according to offspring birth weight patterns among women with spontaneous and iatrogenic term deliveries in Norway (1967-2020). We constructed birth weight quartiles (Qs) by combining standardized birth weight with gestational age in quartiles (Q1, Q2/Q3, and Q4) for the women's first 2 births. Mortality was estimated using Cox regression and expressed as hazard ratios (HRs) with 95% confidence intervals (CIs). Changes in offspring birth weight quartiles were associated with long-term maternal CVD mortality. Compared with women who had 2 term infants in Q2/Q3, women with a first offspring in Q2/Q3 and a second in Q1 had higher mortality risk (HR = 1.33, 95% CI: 1.18, 1.50), while risk was lower if the second offspring was in Q4 (HR = 0.78, 95% CI: 0.67, 0.91). The risk increase associated with having a first infant in Q1 was eliminated if the second offspring was in Q4 (HR = 0.99, 95% CI: 0.75, 1.31). These patterns were similar for women with iatrogenic and spontaneous deliveries. Inclusion of information from subsequent births revealed heterogeneity in maternal CVD mortality which was not captured when using only information based on the first offspring.

No major differences in perinatal and maternal outcomes between uninterrupted embryo culture in time-lapse system and conventional embryo culture.

STUDY QUESTION: Is embryo culture in a closed time-lapse system associated with any differences in perinatal and maternal outcomes in comparison to conventional culture and spontaneous conception? SUMMARY ANSWER: There were no significant differences between time-lapse and conventional embryo culture in preterm birth (PTB, <37 weeks), low birth weight (LBW, >2500 g) and hypertensive disorders of pregnancy for singleton deliveries, the primary outcomes of this study. WHAT IS KNOWN ALREADY: Evidence from prospective trials evaluating the safety of time-lapse incubation for clinical use show similar embryo development rates, implantation rates, and ongoing pregnancy and live birth rates when compared to conventional incubation. Few studies have investigated if uninterrupted culture can alter risks of adverse perinatal outcomes presently associated with IVF when compared to conventional culture and spontaneous conceptions. STUDY DESIGN, SIZE, DURATION: This study is a Swedish population-based retrospective registry study, including 7379 singleton deliveries after fresh embryo transfer between 2013 and 2018 from selected IVF clinics. Perinatal outcomes of singletons born from time-lapse-cultured embryos were compared to singletons from embryos cultured in conventional incubators and 71 300 singletons from spontaneous conceptions. Main perinatal outcomes included PTB and LBW. Main maternal outcomes included hypertensive disorders of pregnancy (pregnancy hypertension and preeclampsia). PARTICIPANTS/MATERIALS, SETTING, METHODS: From nine IVF clinics, 2683 singletons born after fresh embryo transfer in a time-lapse system were compared to 4696 singletons born after culture in a conventional incubator and 71 300 singletons born after spontaneous conception matched for year of birth, parity, and maternal age. Patient and treatment characteristics from IVF deliveries were cross-linked with the Swedish Medical Birth Register, Register of Birth Defects, National Patient Register and Statistics Sweden. Children born after sperm and oocyte donation cycles and after Preimplantation Genetic testing cycles were excluded. Odds ratio (OR) and adjusted OR were calculated, adjusting for relevant confounders. MAIN RESULTS AND THE ROLE OF CHANCE: In the adjusted analyses, no significant differences were found for risk of PTB (adjusted OR 1.11, 95% CI 0.87-1.41) and LBW (adjusted OR 0.86, 95% CI 0.66-1.14) or hypertensive disorders of pregnancy; preeclampsia and hypertension (adjusted OR 0.99, 95% CI 0.67-1.45 and adjusted OR 0.98, 95% CI 0.62-1.53, respectively) between time-lapse and conventional incubation systems. A significantly increased risk of PTB (adjusted OR 1.31, 95% CI 1.08-1.60) and LBW (adjusted OR 1.36, 95% CI 1.08-1.72) was found for singletons born after time-lapse incubation compared to singletons born after spontaneous conceptions. In addition, a lower risk for pregnancy hypertension (adjusted OR 0.72 95% CI 0.53-0.99) but no significant difference for preeclampsia (adjusted OR 0.87, 95% CI 0.68-1.12) was found compared to spontaneous conceptions. Subgroup analyses showed that some risks were related to the day of embryo transfer, with more adverse outcomes after blastocyst transfer in comparison to cleavage stage transfer. LIMITATIONS, REASONS FOR CAUTION: This study is retrospective in design and different clinical strategies may have been used to select specific patient groups for time-lapse versus conventional incubation. The number of patients is limited and larger datasets are required to obtain more precise estimates and adjust for possible effect of additional embryo culture variables. WIDER IMPLICATIONS OF THE FINDINGS: Embryo culture in time-lapse systems is not associated with major differences in perinatal and maternal outcomes, compared to conventional embryo culture, suggesting that this technology is an acceptable alternative for embryo incubation. STUDY FUNDING/COMPETING INTEREST(S): The study was financed by a research grant from Gedeon Richter. There are no conflicts of interest for all authors to declare. TRIAL REGISTRATION NUMBER: N/A.

Effects of daily full-term infant skin-to-skin contact on behavior and cognition at age three - secondary outcomes of a randomized controlled trial.

BACKGROUND: Daily skin-to-skin contact (SSC) during early infancy fosters the long-term development of children born preterm. This is the first randomized controlled trial assessing the potential beneficial effects of daily SSC on executive functioning and socio-emotional behavior of children born full-term. Whether children of mothers who experienced prenatal stress and anxiety benefitted more from SSC was also explored. METHODS: Pregnant women (N = 116) were randomly assigned to a SSC or care-as-usual (CAU) condition. Women in the SSC condition were instructed to perform one hour of SSC daily from birth until postnatal week five. Prenatal stress was measured with questionnaires on general and pregnancy-specific stress and anxiety completed by the mothers in gestational week 37. At child age three, mothers filled in questionnaires on children's executive functioning, and externalizing and internalizing behavior. Analyses were performed in an intention-to-treat (ITT), per-protocol, and dose-response approach. Netherlands Trial Register: NL5591. RESULTS: In the ITT approach, fewer internalizing (95% CI = 0.11-1.00, U = 2148.50, r = .24, p = .001) and externalizing (95% CI = 0.04-2.62, t = 2.04, d = 0.38, p = .04) problems were reported in the SSC condition compared to the CAU condition. Multivariate analyses of variance did not show group differences on executive functioning. Additional analyses of covariance showed no moderations by maternal prenatal stress. CONCLUSIONS: Current findings indicate that early daily SSC in full-term infants may foster children's behavioral development. Future replications, including behavioral observations of child behavior to complement maternal reports, are warranted.

The Associated Factors of Low Birthweight Among Term Singletons in Japan: A Pregnancy Birth Registry Analysis.

BACKGROUND: Progress in reducing the global low birthweight (LBW) has been insufficient. Although the focus has been on preventing preterm birth, evidence regarding LBW in term births is limited. Despite its low preterm birth prevalence, Japan has a higher LBW proportion than other developed countries. This study aimed to examine the prevalence of LBW in term singleton births and its associated factors using a national database. METHODS: We retrospectively analyzed the data of neonates registered in the Japan Society of Obstetrics and Gynecology Successive Pregnancy Birth Registry System who were born 2013-2017. Exclusion criteria included stillbirths, delivery after 42 gestational weeks, and missing data. Logistic regression analyses were performed to investigate the maternal and perinatal factors associated with LBW in term singletons using the data of 715,414 singleton neonates. RESULTS: The overall prevalence of LBW was 18.3%, and 35.7% of LBWs originated from singleton term pregnancies. Multiple logistic regression analyses indicated that both modifiable and non-modifiable factors were independently associated with LBW in term neonates. The modifiable maternal factors included pre-pregnancy underweight, inadequate gestational weight gain, and smoking during pregnancy, while the non-modifiable factors included younger maternal age, nulliparity, hypertensive disorders of pregnancy, cesarean section delivery, female offspring, and congenital anomalies. CONCLUSION: Using the Japanese pregnancy birth registry data, more than one-third of LBWs were found to originate from singleton term pregnancies. Both modifiable and non-modifiable factors were independently associated with LBW in term neonates. Prevention strategies on modifiable risk factor control will be effective in reducing LBW worldwide.

Perinatal mortality and neonatal and maternal outcome per gestational week in term pregnancies: A registry-based study.

INTRODUCTION: Human pregnancy is considered term from 37+0/7 to 41+6/7 weeks. Within this range, both maternal, fetal and neonatal risks may vary considerably. This study investigates how gestational age per week is related to the components of perinatal mortality and parameters of adverse neonatal and maternal outcome at term. MATERIAL AND METHODS: A registry-based study was made of all singleton term pregnancies in the Netherlands from January 2014 to December 2017. Stillbirth and early neonatal mortality, as components of perinatal mortality, were defined as primary outcomes; adverse neonatal and maternal events as secondary outcomes. Neonatal adverse outcomes included birth trauma, 5-minute Apgar score ≤3, asphyxia, respiratory insufficiency, neonatal intensive care unit admission and composite neonatal outcome. Maternal adverse outcomes included instrumental vaginal birth, emergency cesarean section, obstetric anal sphincter injury, postpartum hemorrhage, hypertensive disorders of pregnancy and composite maternal outcome. The primary outcomes were evaluated by comparing weekly prospective risks of stillbirth and neonatal death using a fetuses-at-risk approach. Secondly, odds ratios (OR) for perinatal mortality, adverse neonatal and maternal outcome using a births-based approach were compared for each gestational week with all births occurring after that week. RESULTS: Data of 581 443 births were analyzed. At 37, 38, 39, 40, 41 and 42 weeks, the respective weekly prospective risks of stillbirth were 0.015%, 0.022%, 0.031%, 0.036%, 0.069% and 0.081%; the respective weekly prospective risks of early neonatal death were 0.051%, 0.047%, 0.032%, 0.031%, 0.039% and 0.035%. The OR for adverse neonatal outcomes were the lowest at 39 and 40 weeks. The OR for adverse maternal outcomes, including operative birth, continuously increased with each gestational week. CONCLUSIONS: The prospective risk of early neonatal death for babies born at 39 weeks is lower than the risk of stillbirth in pregnancies continuing beyond 39+6/7 weeks. Birth at 39 weeks was associated with the best combined neonatal and maternal outcome, fewer operative births and fewer maternal and neonatal adverse outcomes compared with pregnancies continuing beyond 39 weeks. This information with appropriate perspectives should be included when counseling term pregnant women.

Association between gestational weight gain and preterm birth and post-term birth: a longitudinal study from the National Vital Statistics System database.

BACKGROUND: To evaluate the association between gestational weight gain (GWG) and preterm birth and post-term birth. METHODS: This longitudinal-based research studied singleton pregnant women from the National Vital Statistics System (NVSS) (2019). Total GWG (kg) was converted to gestational age-standardized z scores. The z-scores of GWG were divided into four categories according to the quartile of GWG, and the quantile 2 interval was used as the reference for the analysis. Univariate and multivariate logistic regression analyses were performed to investigate the association between GWG and preterm birth, post-term birth, and total adverse outcome (preterm birth + post-term birth). Subgroup analysis stratified by pre-pregnancy body mass index (BMI) was used to estimate associations between z-scores and outcomes. RESULTS: Of the 3,100,122 women, preterm birth occurred in 9.45% (292,857) population, with post-term birth accounting for 4.54% (140,851). The results demonstrated that low GWG z-score [odds ratio (OR): 1.04, 95% confidence interval (CI): 1.03 to 1.05, P < 0.001], and higher GWG z-scores (quantile 3: OR: 1.42, 95% CI: 1.41 to 1.44, P < 0.001; quantile 4: OR: 2.79, 95% CI: 2.76 to 2.82, P < 0.001) were positively associated with preterm birth. Low GWG z-score (OR: 1.18, 95% CI: 1.16 to 1.19, P < 0.001) was positively associated with an increased risk of post-term birth. However, higher GWG z-scores (quantile 3: OR: 0.84, 95% CI: 0.83 to 0.85, P < 0.001; quantile 4: 0.59, 95% CI: 0.58 to 0.60, P < 0.001) was associated with a decreased risk of post-term birth. In addition, low GWG z-score and higher GWG z-scores were related to total adverse outcome. A subgroup analysis demonstrated that pre-pregnancy BMI, low GWG z-score was associated with a decreased risk of preterm birth among BMI-obesity women (OR: 0.96, 95% CI: 0.94 to 0.98, P < 0.001). CONCLUSION: Our result suggests that the management of GWG may be an important strategy to reduce the number of preterm birth and post-term birth.

Risk of early birth by body mass index in a propensity score-matched sample: A retrospective cohort study.

OBJECTIVE: Evaluate the risk of preterm (<37 weeks) or early term birth (37 or 38 weeks) by body mass index (BMI) in a propensity score-matched sample. DESIGN: Retrospective cohort analysis. SETTING: California, USA. POPULATION: Singleton live births from 2011-2017. METHODS: Propensity scores were calculated for BMI groups using maternal factors. A referent sample of women with a BMI between 18.5 and <25.0 kg/m2 was selected using exact propensity score matching. Risk ratios for preterm and early term birth were calculated. MAIN OUTCOME MEASURES: Early birth. RESULTS: Women with a BMI <18.5 kg/m2 were at elevated risk of birth of 28-31 weeks (relative risk [RR] 1.2, 95% CI 1.1-1.4), 32-36 weeks (RR 1.3, 95% CI 1.2-1.3), and 37 or 38 weeks (RR 1.1, 95% CI 1.1-1.1). Women with BMI ≥25.0 kg/m2 were at 1.2-1.4-times higher risk of a birth <28 weeks and were at reduced risk of a birth between 32 and 36 weeks (RR 0.8-0.9) and birth during the 37th or 38th week (RR 0.9). CONCLUSION: Women with a BMI <18.5 kg/m2 were at elevated risk of a preterm or early term birth. Women with BMI ≥25.0 kg/m2 were at elevated risk of a birth <28 weeks. Propensity score-matched women with BMI ≥30.0 kg/m2 were at decreased risk of a spontaneous preterm birth with intact membranes between 32 and 36 weeks, supporting the complexity of BMI as a risk factor for preterm birth. TWEETABLE ABSTRACT: Propensity score-matched women with BMI ≥30 kg/m2 were at decreased risk of a late spontaneous preterm birth.

Term breech presentation-Intended cesarean section versus intended vaginal delivery-A systematic review and meta-analysis.

INTRODUCTION: Three per cent of all infants are born in breech presentation, still the preferred way to deliver them remains controversial. The objective of this systematic review was to assess the safety for the mother and child depending on intended mode of delivery when the baby is in breech position at term. MATERIAL AND METHODS: The population (P) was pregnant women with a child in breech presentation, from gestational week 34+0 . The intervention (I) was the intention to deliver by cesarean section, the comparison (C) was the intention to deliver vaginally. Outcomes (O) were perinatal mortality, perinatal morbidity, maternal mortality, maternal morbidity, conversion of delivery mode, and the mother's experience. Systematic literature searches were performed. We included randomized trials, cohort studies with more than 500 women/group and case series for more than 15 000 women published between 1990 and October 2021, written in English or the Nordic languages. The certainty of evidence was assessed using the GRADE approach and data were pooled in meta-analyses. PROSPERO registration number: CRD42020209546. RESULTS: Thirty-two articles were included (with 530 604 women). The certainty of evidence was moderate or low because the study designs were mostly retrospective cohort studies. The only randomized trial showed reduced risk of perinatal mortality for planned cesarean section, risk ratio (RR) 0.27 (95% confidence interval [CI] 0.08-0.97, 2078 women, low certainty of evidence), stillbirths excluded. A meta-analysis of cohort studies resulted in a similar estimate, RR 0.36 (95% CI 0.25-0.51, 21 studies, 388 714 women, low certainty of evidence). We also found reduced risk for outcomes representing perinatal morbidity 0-28 days: 5-min Apgar score less than 7 in one randomized controlled trial: RR 0.27 (95% CI 0.12-0.58, 2033 women, moderate certainty of evidence), and in a meta-analysis: RR 0.1 (95% CI 0.14-0.26, 18 studies, 217 024 women, moderate certainty of evidence); APGAR score less than 4 at 5 min: RR 0.39 (95% CI 0.19-0.81, five studies, 44 498 women, low certainty of evidence); and pH less than 7.0: RR 0.23 (95% CI 0.12-0.43, four studies, 13 440 women, low certainty of evidence). Outcomes for the mother were similar in the groups except for reduced risk for experience of urinary incontinence in the group of planned cesarean section: RR 0.62 (95% CI 0.41-0.93, one study, 1940 women, low certainty of evidence). The conversion rate from planned vaginal delivery to emergency cesarean section ranged from 16% to 51% (median 41.8%, 10 studies, 50 763 women, moderate certainty of evidence). CONCLUSIONS: Intended cesarean section may reduce the risk of perinatal mortality and perinatal as well as some maternal morbidity compared with intended vaginal delivery. It is uncertain whether there is any difference in maternal mortality. The conversion rate from intended vaginal delivery to emergency cesarean section is high.

Maternal & perinatal outcome of fever in pregnancy in the context of dengue - A retrospective observational study.

Background & objectives: Pregnant women with dengue infection may be at increased risk of adverse maternal-foetal outcomes. This study was conducted to assess the maternal and perinatal outcomes in women who presented with fever and diagnosed to have dengue infection during pregnancy. Methods: A retrospective observational study was conducted on pregnant women admitted with fever, in a tertiary referral centre in South India, during January 2015 to December 2018. We compared outcomes of women diagnosed with dengue with that of women without dengue. The study outcomes included pre-term birth, stillbirth, low-birth weight (LBW), maternal mortality and thrombocytopenia. Results: During the study period, there were six maternal deaths following complications from dengue infection. Higher rates of thrombocytopenia (24.7% vs. 14.6%, P=0.02) were noted among those with recent dengue infection. The risk of still birth was 2.67 [95% confidence interval (CI) 1.09, 6.57], LBW [risk ratio (RR) 1.13, 95% CI 0.87, 1.45] and pre-term birth (RR 1.33, 95% CI 0.89, 1.97) among the cases. Interpretation & conclusions: Occurrence of adverse maternal and foetal outcomes was increased in pregnant women with fever diagnosed with dengue infection. Future studies are needed to formulate the optimum monitoring and treatment strategies in pregnant women, where dengue can have additive adverse effects to other obstetric complications.

Respiratory responses to hypoxia during rest and exercise in individuals born pre-term: a state-of-the-art review.

The pre-term birth survival rate has increased considerably in recent decades, and research investigating the long-term effects of premature birth is growing. Moreover, altitude sojourns are increasing in popularity and are often accompanied by various levels of physical activity. Individuals born pre-term appear to exhibit altered acute ventilatory responses to hypoxia, potentially predisposing them to high-altitude illness. These impairments are likely due to the use of perinatal hyperoxia stunting the maturation of carotid body chemoreceptors, but may also be attributed to limited lung diffusion capacity and/or gas exchange inefficiency. Aerobic exercise capacity also appears to be reduced in this population. This may relate to the aforementioned respiratory impairments, or could be due to physiological limitations in pulmonary blood flow or at the exercising muscle (e.g. mitochondrial efficiency). However, surprisingly, the debilitative effects of exercise when performed at altitude do not seem to be exacerbated by premature birth. In fact, it is reasonable to speculate that pre-term birth could protect against the consequences of exercise combined with hypoxia. The mechanisms that underlie this assertion might relate to differences in oxidative stress responses or in cardiopulmonary morphology in pre-term individuals, compared to their full-term counterparts. Further research is required to elucidate the independent effects of neonatal treatment, sex differences and chronic lung disease, and to establish causality in some of the proposed mechanisms that could underlie the differences discussed throughout this review. A more in-depth understanding of the acclimatisation responses to chronic altitude exposures would also help to inform appropriate interventions in this clinical population.

Impact of early term and late preterm birth on infants' neurodevelopment: evidence from a cohort study in Wuhan, China.

BACKGROUND: The incidences of early term and late preterm birth have increased worldwide during recent years. However, there is a lack of prospective study about the influence of early term and late preterm birth on infants' neurodevelopment, especially at the early stage. Therefore, we conducted this cohort study to investigate the impact of early term and late preterm birth on infants' neurodevelopment within 6 months. METHODS: This cohort study was conducted in Wuhan, China, between October 2012 and September 2013. A total of 4243 singleton infants born within 34-41 weeks of gestation at Wuhan Children's Hospital were included. The Gesell Developmental Scale (GDS) was utilized to evaluate the neurodevelopment of infants. RESULTS: Among the 4243 included participants, 155 (3.65%) were late preterm infants, 1288 (30.36%) were early term infants, and 2800 (65.99%) were full term infants. After adjusted for potential confounders, significant negative relationship was shown between late preterm birth and development quotient (DQ) in all domains of neurodevelopment: gross motor (ß = - 17.42, 95% CI: - 21.15 to - 13.69), fine motor (ß = - 23.61, 95% CI: - 28.52 to - 18.69), adaptability (ß = - 10.10, 95% CI: - 13.82 to - 6.38), language (ß = - 6.28, 95% CI: - 9.82 to - 2.74) and social behavior (ß = - 5.99, 95% CI: - 9.59 to - 2.39). There was a significant negative trend for early term birth in DQ of fine motor (ß = - 2.01, 95% CI: - 3.93 to - 0.09). Late preterm infants had a significantly elevated risk of neurodevelopmental delay in domains of gross motor (adjusted OR = 3.82, 95% CI: 2.67 to 5.46), fine motor (adjusted OR = 3.51, 95% CI: 2.47 to 5.01), and adaptability (adjusted OR = 1.60, 95% CI: 1.12 to 2.29), whereas early term birth was significantly associated with neurodevelopmental delay of fine motor (adjusted OR = 1.22, 95% CI: 1.05 to 1.42). CONCLUSIONS: This study suggested that late preterm birth mainly elevated the risk of neurodevelopmental delay of gross motor, fine motor, and adaptability, whereas early term birth was associated with the developmental delay of fine motor within 6 months. Further research is needed to determine the effectiveness and necessity of the interventions at the early stage for early term and late preterm infants who had suspected neurodevelopmental delay.

Guideline No. 424: Umbilical Cord Management in Preterm and Term Infants.

OBJECTIVE: To assess the impact of deferred (delayed) cord clamping (DCC) and umbilical cord milking in singleton and twin gestations on maternal and infant mortality and morbidity. TARGET POPULATION: People who are pregnant with preterm or term singletons or twins. BENEFITS, HARMS, AND COSTS: In preterm singletons, DCC for (ideally) 60 to 120 seconds, but at least for 30 seconds, reduces infant risk of mortality and morbidity. DCC in preterm twins is associated with some benefits. In term singletons, DCC for 60 seconds improves hematological parameters. In very preterm infants, umbilical cord milking increases risk for intraventricular hemorrhage. EVIDENCE: Searches of Medline, PubMed, Embase, and the Cochrane Library from inception to March 2020 were undertaken using Medical Subject Heading (MeSH) terms and key words related to deferred cord clamping and umbilical cord milking. This document represents an abstraction of the evidence rather than a methodological review. VALIDATION METHODS: The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations). INTENDED USERS: Maternity and newborn care providers.

Comparison of perianal skin barrier function with moisturizer application in Japanese full-term newborns.

BACKGROUND/OBJECTIVES: Some full-term newborns present with erythema and irritation of the buttocks and perianal area as early as the first 4 days of their lives. The effect of moisturizers in protecting this vulnerable skin has not been rigorously studied. This study aimed to clarify whether there is a difference in perianal skin barrier function with and without moisturizer application in the first month of life. METHODS: Comparative investigation of 118 full-term newborns was performed, and they were allocated to intervention (n = 63) and control groups (n = 55). The intervention group received moisturizer application to the perianal area, and the control group received care without application of moisturizer to the perianal area from the first day of life until the 1-month visit. Transepidermal water loss (TEWL), stratum corneum hydration (SCH), and skin surface pH in the perianal area were measured as the indicators of skin barrier function on days 1 and 5 after birth and at the 1-month visit. RESULTS: At the 1-month visit, TEWL was significantly decreased (intervention, 19.4 g/m2 /h; control, 25.8 g/m2 /h; p = .00) and SCH was significantly increased (intervention, 58.8 arbitrary units (a.u.); control, 46.5 a.u.; p = .00) in newborns using perianal moisturizer. The skin surface pH was not significantly different. CONCLUSIONS: The use of moisturizer was effective in protecting the skin barrier function of the perianal skin. Further investigations are needed to determine the effect on the frequency and extent of rashes in the perianal area.

Estimation of gestational age in neonates using clavicular-pubis length on routine chest-abdomen radiographs.

BACKGROUND: Neonatal diseases differ depending on gestational age and weight. In the setting of an emergency in the neonatal intensive care unit (NICU), relevant clinical information is often not available when the first neonatal radiograph is obtained. When reading an initial chest-abdomen radiograph, the paediatric radiologist needs gestational age data for best radiologic practice. A transverse diameter of the chest has been previously described to estimate gestational age (GA). OBJECTIVES: To determine the strength of the correlation between GA/weight and clavicular-pubis length (CPL) on admission radiographs; to obtain a quadratic formula based on the correlation of CPL with GA and to demonstrate if a more simplified formula used by our group works as efficiently as the formula provided by the regression analysis. MATERIALS AND METHODS: A retrospective study was approved by the institutional review board and informed consent was waived. The length from the medial aspect of the clavicle to the pubic bone was measured on the initial portable chest-abdomen radiographs of 260 patients admitted to the NICU in 2016. Regression analysis was performed to investigate the association between CPL and GA/birth weight. RESULTS: One hundred eleven females and 149 males with GA between 23 and 42 weeks were evaluated. CPL was statistically associated with both GA (P<0,01) and birth weight. The estimation can be expressed with an equation of the model: GA (weeks) = (CPL in cm - 1.98)/0.42. A simplified formula: GA (weeks) = (CPL in cm) ×2+2, strongly correlates with the equation model. CONCLUSION: In patients in whom it is not known, GA can be estimated by measuring the length between medial clavicle and symphysis pubis using the formulae we propose.

Effects of skin-to-skin contact on full-term infants' stress reactivity and quality of mother-infant interactions.

Skin-to-skin contact (SSC) between mothers and their infants has beneficial effects in both preterm and full-term infants. Underlying mechanisms are largely unknown. This randomized controlled trial assessed whether daily SSC in full-term mother-infant dyads: (1) decreases infants' cortisol and behavioral reactivity to a mild naturalistic stressor, and (2) facilitates interaction quality between infants and mothers (i.e., improved maternal caregiving behavior and mother-infant adrenocortical synchrony). Pregnant Dutch women (N = 116) were recruited and randomly allocated to an SSC or care-as-usual condition. The SSC condition performed 1 h of SSC daily, from birth until postnatal week 5. In week 5, mothers bathed the infant (known mild stressor). Infant and maternal cortisol was sampled at baseline, 25 and 40 min after bathing, and infant and maternal behavior was rated. Results did not indicate effects of SSC on infant behavioral and cortisol reactivity to the bathing session. Similarly, no effect of SSC was found on maternal caregiving behavior and mother-infant adrenocortical synchrony. In conclusion, the findings provide no evidence that daily mother-infant SSC is associated with full-term infants' behavioral and adrenocortical stress reactivity or mother-infant interaction quality. Future studies should replicate these findings and unveil other potential mechanisms underlying beneficial effects of SSC.

The association between birth by caesarean section at term and offspring cognitive and academic performance: A birth cohort study.

BACKGROUND: Caesarean section (CS) is associated with an increased risk of adverse health outcomes for both mothers and offspring. The evidence for an association between CS and reduced offspring cognitive and academic performance has been inconsistent, with considerable limitations. AIM: The aim of this study is to compare cognitive and academic performance in childhood and early adulthood in offspring delivered by CS with those delivered vaginally at term. MATERIALS AND METHODS: Data on 4327 mothers and offspring from a longitudinal birth cohort study were analysed. Offspring cognitive performance was measured by the Picture Peabody Vocabulary Test-Revised (PPVT-R) at ages five and 21 and the Raven's Standard Progressive Matrices at age 14. Academic achievement was assessed using the Wide Range Achievement Test at age 14. RESULTS: After adjustment for confounding factors, there was no statistically significant association between cognitive performance and offspring birth mode at age five (P = 0.11). The adjusted difference of mean scores at five years on the PPVT-R for elective CS birth compared to those born by vaginal delivery was -2.2 (95% confidence interval (CI) -4.3 to -0.2), whereas for emergency CS it was 0.0 (95% CI -2.0 to 2.0). There were no differences in cognitive or academic performance at ages 14 and 21. CONCLUSION: Birth mode was not significantly associated with offspring cognitive or academic performance. Our study does not support concerns that CS is associated with a reduction in cognitive performance.