Maternal selenium,copper and zinc concentrations in pregnancy associated with small‐for‐gestational‐age infants

Pregnancy during adolescence increases the risk of adverse pregnancy outcome, especially small‐for‐gestational‐age (SGA) birth, which has been linked to micronutrient deficiencies. Smoking has been shown to be related to lower micronutrient concentrations. Different ethnicities have not been examined. We used a subset from a prospective observational study, the About Teenage Eating study consisting of 126 pregnant adolescents (14–18‐year‐olds) between 28 and 32 weeks gestation. Micronutrient status was assessed by inductively coupled mass spectrometry. Smoking was assessed by self‐report and plasma cotinine, and SGA was defined as infants born <10th corrected birthweight centile. The main outcome measures were as follows: (1) maternal plasma selenium, copper and zinc concentrations in adolescent mothers giving birth to SGA vs. appropriate‐for‐gestational‐age (AGA) infants; and (2) comparison of micronutrient concentrations between women of different ethnicities and smoking habits. The plasma selenium {mean ± standard deviation (SD) [95% confidence interval (CI)]} concentration was lower in the SGA [n = 19: 49.4 ± 7.3 (CI: 45.9, 52.9) µg L^?1] compared with the AGA [n = 107: 65.1 ± 12.5 (CI: 62.7, 67.5) µg L^?1; P < 0.0001] group. Smoking mothers had a lower selenium concentration compared with non‐smokers (P = 0.01) and Afro‐Caribbean women had higher selenium concentrations compared with White Europeans (P = 0.02). Neither copper nor zinc concentrations varied between groups. Low plasma selenium concentration in adolescent mothers could contribute to the risk of delivering an SGA infant, possibly through lowering placental antioxidant defence, thus directly affecting fetal growth. Differences in plasma selenium between ethnicities may relate to variation in nutritional intake, requiring further investigation.     

Optimal birth weight percentile cut‐offs in defining small‐ or large‐for‐gestational‐age

Aims: It remains questionable what birth weight for gestational age percentile cut‐offs should be used in defining clinically important poor or excessive foetal growth. We aimed to evaluate the optimal birth weight percentile cut‐offs for defining small‐ or large‐for‐gestational‐age (SGA or LGA). Methods: In a birth cohort‐based analysis of 17 979 120 non‐malformation singleton live births, U.S. 1995–2001, we assessed the optimal birth weight percentile cut‐offs for defining SGA and LGA. The 25th–75th percentile group served as the reference. Primary outcomes are the risk ratios (RR) of neonatal death and low 5‐min Apgar score (<4) comparing SGA or LGA versus the reference group. More than 2‐fold risk elevations were considered clinically significant. Results: The 15th birth weight cut‐off already identified SGA infants at more than 2‐fold risk of neonatal death at pre‐term, term or post‐term, except for extremely pre‐term births <28 weeks (continuous risk reductions over increasing birth weight percentiles). LGA was associated with a reduced risk of low 5‐min Apgar score at pre‐term, but an elevated risk at term and post‐term. The 97th cut‐off identified LGA infants at 2‐fold risk of low 5‐min Apgar at term. Conclusion: The commonly used 10th and 90th birth weight percentile cut‐offs for defining SGA and LGA respectively seem largely arbitrary. The 15th and 97th percentiles may be the optimal cut‐offs to define SGA and LGA respectively.     

Systematic review indicates postnatal growth in term infants born small‐for‐gestational‐age being associated with later neurocognitive and metabolic outcomes

We systematically reviewed papers published in English between 1994 and October 2015 on how postnatal weight gain and growth affect neurodevelopment and metabolic outcomes in term‐born small‐for‐gestational‐age (SGA) infants. Two randomised trials reported that enriched infant formulas that promoted early growth also increased fat mass, lean mass and blood pressure (BP), but had no effect on early neurocognitive outcomes. Meanwhile, 31 observational studies reported consistent positive associations between postnatal weight gain and growth with neurocognitive outcomes, adiposity, insulin resistance and BP. Conclusion: Few intervention studies exist, despite consistent positive associations between early growth and neurocognition in term‐born SGA infants.     

A case–control study to examine the association between breastfeeding during late pregnancy and risk of a small‐for‐gestational‐age birth in Lima,Peru

Excessive demands on maternal nutritional status may be a risk factor for poor birth outcomes. This study examined the association between breastfeeding during late pregnancy (≥28 weeks) and the risk of having a small‐for‐gestational‐age (SGA) newborn, using a matched case–control design (78 SGA cases: birthweight <10th percentile for gestational age; 150 non‐SGA controls: 50th percentile <birthweight <90th percentile for gestational age). Between March 2006 and April 2007, project midwives visited daily three government hospitals in Lima, Peru and identified cases and matched controls based on hospital, gestational age, and inter‐gestational period. Mothers were interviewed and clinical chart extractions were completed. Factors associated with risk of SGA were assessed by their adjusted odds ratios (aOR) from conditional logistic regression. Exposure to an overlap of breastfeeding during late pregnancy was not associated with an increased risk of having a SGA newborn [aOR = 0.58, 95% confidence interval (CI): 0.10–3.30]. However, increased risk was associated with having a previous low‐birthweight birth (aOR = 6.53; 95% CI: 1.43–29.70) and a low intake of animal source foods (<25th percentile; aOR = 2.26; 95% CI: 1.01–5.04), and tended to be associated with being short (<150 cm; aOR = 2.05; 95% CI: 0.92–4.54). This study found no evidence to support the hypothesis that breastfeeding during late pregnancy increases the risk for SGA; however, studies with greater statistical power are needed to definitively examine this possible association and clarify whether there are other risks to the new baby, the toddler and the pregnant woman.     

Refeeding syndrome in a small‐for‐dates micro‐preemie receiving early parenteral nutrition

This report describes a small‐for‐date extremely low birth weight infant who manifested bradycardic events, respiratory failure, and hemolytic jaundice during her first week of life. These complications were attributed to severe hypophosphatemia and hypokalemia. Inadequate supply and refeeding syndrome triggered by early aggressive parenteral nutrition were responsible for electrolyte abnormalities.     

Gestational age assessment in Japanese low birthweight infants

We evaluated the validity of the Ballard scoring system for assessing gestational age in Japanese low birthweight infants. Infants included in this study were 116 neonates who were admitted to seven hospitals in Hokkaido. Gestational ages of all infants were prenatally established by ultrasonographic measurement of the crown-rump length performed between 8 and 12 weeks of gestation (clinical age). Of these, 74 infants were appropriate for gestational age (AGA) and the remaining were small for gestational age (SGA). Mean birthweight was 1703 g and 34% (39/116) were <1500 g. The correlation coefficient for the total population was 0.93 (P < 0.001). Although mean Ballard age tended to overestimate clinical age, mean differences between Ballard age and clinical age did not exceed 0.6 weeks. Agreement within 2 weeks among all infants was 86.2%. Percentages of agreement within 2 weeks did not differ to a statistically significant degree between AGA and SGA. These results indicate that the Ballard method is of value in assessing gestational age in Japanese low birthweight infants.     

Gestational weight gain and newborn anthropometric outcomes in rural Bangladesh

Low gestational weight gain (GWG) is a known predictor of fetal growth restriction in higher income countries, but there is little information on this association in lower income countries. Our objective is to describe the association between GWG and birth outcomes among pregnant women in rural Bangladesh. Pregnant women were identified in a community‐based programme and enrolled into the study at an average of 13 weeks' gestation (n = 4,011). Maternal weight and height were measured at enrolment, maternal weight was measured at 36 weeks' gestation, and newborns were measured after birth. Rate of GWG (g/weeks) was calculated, and women were categorized as having adequate or inadequate GWG (Institute of Medicine recommendations). Newborn anthropometric outcomes included weight‐for‐age z score (WAZ), length‐for‐age z score (LAZ), head‐circumference‐for‐age z score (HCZ), body mass index (BMI)‐for‐age z score (BMIZ), low birthweight (LBW < 2,500 g), WAZ < ?2, LAZ < ?2, HCZ < ?2, BMIZ < ?2, and small for gestational age (SGA: <10th percentile). Multivariate models were adjusted for confounders. Only 26% of the 2,562 women in these analyses had adequate GWG. Compared with newborns of women with inadequate GWG, infants of women with adequate GWG had a lower risk of adverse anthropometric outcomes (relative risk [95% confidence interval]: LBW = 0.68 [0.59, 0.80], LAZ < ?2 = 0.64 [0.51, 0.80], HCZ < ?2 = 0.75 [0.60, 0.93], BMIZ < ?2 = 0.70 [0.59, 0.83], and SGA = 0.80 [0.73, 0.86]), but there was no significant difference in mean (SE) duration of gestation, 39.7 (0.08) versus 39.7 (0.05) weeks. In this population, GWG rate is a strong predictor of newborn anthropometric outcomes, but not duration of gestation.     

Body composition in appropriate and in small for gestational age infants

The body composition of 70 appropriate for gestational age newborn infants whose gestational age ranged from 32 to 41 weeks was determined by dual-energy X-ray absorptiometry during the first 48 h of life. The evolution of the bone mineral content, fat and lean mass was well correlated with gestational age ( r = 0.66, r = 0.66 and r = 0.82. respectively) but even more closely with birthweight ( r = 0.85, r = 0.91 and r = 0.97. respectively). The body composition of 20 symmetric small for gestational age infants (mean gestational age ± SD = 38.1 ± 1.2 weeks: mean birthweight ± SD = 2117 ± 183 g) was also studied. The total body fat, the lean mass and the bone mineral content of small for gestational age infants were decreased significantly in comparison with those of appropriate for gestational age infants with the same gestational age ( p ≤ 0.05, p ≤ 0.0001 and p ≤ 0.05) but was not significantly different from those observed in appropriate for gestational age infants of the same birthweight.