Human placenta metabolizes fatty acids: implications for fetal fatty acid oxidation disorders and maternal liver diseases

The role of fat metabolism during human pregnancy and in placental growth and function is poorly understood. Mitochondrial fatty acid oxidation disorders in an affected fetus are associated with maternal diseases of pregnancy, including preeclampsia, acute fatty liver of pregnancy, and the hemolysis, elevated liver enzymes, and low platelets syndrome called HELLP. We have investigated the developmental expression and activity of six fatty acid beta-oxidation enzymes at various gestational-age human placentas. Placental specimens exhibited abundant expression of all six enzymes, as assessed by immunohistochemical and immunoblot analyses, with greater staining in syncytiotrophoblasts compared with other placental cell types. beta-Oxidation enzyme activities in placental tissues were higher early in gestation and lower near term. Trophoblast cells in culture oxidized tritium-labeled palmitate and myristate in substantial amounts, indicating that the human placenta utilizes fatty acids as a significant metabolic fuel. Thus human placenta derives energy from fatty acid oxidation, providing a potential explanation for the association of fetal fatty acid oxidation disorders with maternal liver diseases in pregnancy.

Anogenital distance is determined during early gestation in humans

STUDY QUESTION

Does cord blood androgen level obtained at birth affect the AGD in human newborns?

SUMMARY ANSWER

In human newborns, though males have a significantly longer AGD compared to females (as early as 22 weeks of gestation) the AGD is not affected by androgen levels at birth in both the sexes.

WHAT IS KNOWN ALREADY

Animal studies have reported a critical time period in early fetal life, termed the masculinization programming window (MPW) during which AGD is fixed by in utero androgen action and is unaffected by testosterone levels later during gestation. Thus, AGD may serve as a lifelong biomarker of androgen exposure during this window. This MPW is hypothesized to occur in humans at 8-14 weeks of gestation during which AGD is fixed. The effect of androgens (testosterone) on AGD after the MPW in humans is not known. Furthermore, altered AGD has been associated with various human reproductive health disorders in both males and females.

STUDY DESIGN, SIZE, DURATION

A prospective descriptive cohort study was performed using data from randomly selected neonates (n = 205) born at a single center over a period of 1 year (August 2015 to August 2016).

PARTICIPANTS/MATERIALS, SETTING, METHODS

AGDs in male (n = 117) and female infants (n = 88) together with penile width, glans girth and stretched penile length were measured by trained caregivers. Gestation ranged from 22 to 41 weeks and infants were examined within 24 h of birth (within 48-72 h in very sick preterm infants after clinical stabilization). AGD-1 was measured from the center of the anus to the posterior base of scrotum in males or to the posterior fourchette in females. AGD-2 was measured from the center of the anus to the anterior base of the penis in males or to the clitoris in females. Sex steroid hormones (testosterone, 17-OH progesterone (17-OHP) and androstenedione) were measured in serum prepared from umbilical cord blood samples taken at birth, using liquid chromatography-tandem mass spectrometry.

MAIN RESULTS AND THE ROLE OF CHANCE

Males had a significantly lower gestational age (mean ± SD; 34.6 ± 4.9 versus 36.1 ± 4.1 weeks, P = 0.04), and a significantly longer AGD-1 (mean ± SD; 21.6 ± 6.0 versus 12.7 ± 3.8 mm, P < 0.001) and AGD-2 (41.9 ± 8.7 versus 33.9 ± 7.1 mm, P = 0.004) compared to female infants, respectively. The cord serum testosterone levels were significantly higher for male than female infants [median, interquartile range; 13.0 (7.3, 20.5) versus 4.1 (2.5, 5.9), ng/dl, P < 0.001]. There was no difference in levels of 17-OHP (P = 0.697) or androstenedione (P = 0.601) between the two sexes. On multiple regression analysis after adjusting for potential confounders, none of the AGD's in both males and females correlated with any sex steroid hormonal levels. We also provide normative charts for penile length, penile width and glans girth in preterm and term infants.

LIMITATIONS, REASONS FOR CAUTION

No data were collected on family history of genital malformation, infertility or hormonal disorders, parental endocrine-disrupting chemical exposure or diet pattern, any of which might have influenced the AGD and/or sex steroid hormone levels in the offspring.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that AGD in humans, like animals, is fixed in early gestation (likely during the hypothesized MPW) and is unaffected by androgen levels thereafter. Thus, AGD can serve as a biomarker of in utero androgen action during early gestation (likely 8-14 weeks) in humans. As such, causes of human newborn and adult reproductive health disorders, such as endocrine disruptors, should be explored during early gestation. However, further larger studies are needed to help corroborate these findings.

STUDY FUNDING/COMPETING INTERESTS

No specific funding was obtained for this study, and all authors have no conflict of interest to declare.

Early detection of bacteremia in the neonatal intensive care unit using the new BACTEC system

OBJECTIVE

With the newer techniques of culture analysis such as the BACTEC 9240 fluorometric detection system, detecting bacteremia in the neonate may be possible in a significantly shorter time. We hypothesized that neonatal bacteremia can be detected in less than 48 hours by this method.

STUDY DESIGN

Our study included a retrospective review of 613 blood cultures obtained during the period August 1, 1995 to March 18, 1996 taken from 325 infants who had cultures drawn with a sepsis work-up and/or repeat cultures who had initial positive cultures in our Neonatal Intensive Care Unit. Results of blood cultures were studied in conjunction with the variables of body weight, gestational age, organism grown, complete blood count (CBC), and timing of positive cultures. Statistical analyses were performed using Fisher's and two-tailed Student's t tests.

RESULTS

The results showed that of 325 infant blood cultures 49 (15%) were positive. Of these, 64% were coagulase-negative staphylococci, 14% viridans streptococci, 8% Escherichia coli, 4% Enterococcus sp., 4% Pseudomonas sp., 2% Enterobacter sp., 2% Klebsiella sp., and 2% Candida albicans. Of the positive blood cultures taken from infants not on antibiotics at the time of culture, 54% were detected positive at 18 hours, 71% at 24 hours, and 100% by 30 hours. Detection time by organism type was as follows: coagulase-negative staphylococci, 21.7 hours; viridans streptococci, 15.6 hours; E. coli, 7.5 hours; Enterococcus sp., 12 hours; Enterobacter sp., 5 hours; Klebsiella sp., 10 hours; and Pseudomonas sp., 12 hours.

CONCLUSION

Our results indicate that the BACTEC 9240 fluorometric detection system helps in early identification of neonatal bacteremia (in 24 to 30 hours), with Gram-negative organisms being detected earlier than Gram-positive organisms (p < 0.05) and having significantly higher immature neutrophils in a CBC (I:T ratio of > or = 0.2 (p < 0.001). Early detection of neonatal bacteremia using this method will allow earlier diagnosis and appropriate treatment of the potentially bacteremic and bacteremic infant.

Low caloric intake and high fluid intake during the first week of life are associated with the severity of bronchopulmonary dysplasia in extremely low birth weight infants

OBJECTIVE

To study whether there is an association between nutritional intake during the first week of life and severity of bronchopulmonary dysplasia (BPD) in extremely low birth weight (ELBW) infants.

METHODS

In a retrospective cohort study, medical records of all ELBW infants admitted to our Neonatal Intensive Care Unit (2010-2017) were reviewed for infants' demographics, clinical characteristics, nutritional intake during their first week of life, and BPD risk factors.

RESULTS

During the study period 226 infants were identified of whom 67% (151/226) had moderate-severe BPD and the rest served as controls. Overall infants with moderate-severe BPD were younger, smaller, and spent more time on mechanical ventilation than their controls [(mean±standard deviation) 24.7±1.7 vs. 26.8±2.0 weeks gestational age (p < 0.001); 678±154 vs. 837±129 grams (p < 0.001); and 37.9±23.6 vs. 13.7±15.3 days (p < 0.001) respectively]. During the first week of life, the average caloric, carbohydrate, protein and lipid intakes were significantly lower, and the average fluid intake was significantly higher in the moderate-severe BPD than the control group. After adjustment for confounders, fluid intake, and days on mechanical ventilation were significantly associated with moderate-severe BPD with an odds ratio [OR (95% confidence interval)] of 1.03 (1.01-1.04), and 1.05 (1.03-1.07) respectively. Daily caloric intake was associated with an increased risk for moderate-severe BPD [OR: 0.94 (0.91-0.97)].

CONCLUSION

Low caloric intake, and high fluid intake during the first week of life are associated with the severity of BPD in ELBW infants.

Hospital readmission and morbidity following early newborn discharge

To examine causes of newborn hospital readmission and morbidity related to early nursery discharge, we reviewed the charts of 664 newborns readmitted from home under the age of 15 days, between 1993 and 1995. Early discharge (ED) was defined as nursery length of stay of < or = 2 days. Morbidity related to ED: onset of symptoms within 1 day of ED; and in diseases with insidious onset: serum bilirubin level > 20 mg/dL (340 mumol/L), or dehydration following poor breastfeeding since birth. Seventeen percent of all readmitted infants had ED-related morbidity; 9% had major morbidity. Onset of symptoms prior to the age of 3 days occurred in 43% of ductal-dependent cardiac lesions, intestinal obstruction, seizures, and major infections. Morbidity was less pronounced in infants who were followed up within 2 days following ED. Specific findings related to subsequent morbidity were identified in the perinatal history of infants who were readmitted with major infections and with hyperbilirubinemia. Our findings suggest that: (1) close to half of the cases with acute-onset major morbidity can be identified within 3 days of birth, and (2) attention to the perinatal history and timely follow-up will contribute to a reduction in both morbidity and complications.

Slow enteral feeding decreases risk of transfusion associated necrotizing enterocolitis

BACKGROUND

Necrotizing Enterocolitis (NEC) is a multifactorial condition where PRBC transfusion is associated with necrotizing enterocolitis (TANEC) in about a third of all cases of NEC. We have investigated the role of feeding practices in incidence of TANEC. We sought to compare infants diagnosed with TANEC versus infants diagnosed with classic NEC and investigated the effects of a standardized slow enteral feeding (SSEF) protocol on TANEC incidence as well as the effects of SSEF on growth of infants with NEC.

METHODS

We conducted a retrospective cohort study, where medical records of infants born in a tertiary care neonatal intensive care unit (level IIIb) from January 1997 to May 2014 with birth weight < 1500 grams and gestational age≤34 weeks with NEC stage IIa or greater according to the modified Bell's staging were reviewed.

RESULTS

During the study period, 111 infants developed NEC, and 41/111 (37%) were diagnosed with TANEC. Infants with TANEC were smaller, more premature, had higher SNAPPE scores and were more anemic prior to transfusion compared with infants with 'classic NEC'. The severity of NEC did not differ between the two groups, however, infants with TANEC had worse outcomes and longer NICU stays. Introduction of SSEF protocol, led to a significant decrease in TANEC. There was no difference in weight and head circumference of infants in the two groups at 2 years corrected age.

CONCLUSION

SSEF led to a significant reduction in the incidence of TANEC without impairing growth at 2 years corrected age.

The concomitant use of vancomycin and piperacillin-tazobactam is associated with acute kidney injury (AKI) in extremely low birth weight infants (ELBW)

BACKGROUND

Late-onset sepsis is common in extremely low birth weight (ELBW) infants, and it leads to the use of antibiotics to cover resistant organisms, which can be nephrotoxic. Here we have investigated the role of vancomycin plus piperacillin-tazobactam on the rate of acute kidney injury (AKI).

METHODS

In a retrospective case-control study, medical records of all ELBW infants who were admitted to our Neonatal Intensive Care Unit (NICU) with late onset sepsis who were prescribed vancomycin plus piperacillin-tazobactam were reviewed for demographics, clinical characteristics, use of potential nephrotoxic medications and outcomes.

RESULTS

During the study period, 264 patients were admitted, of whom 28.4%(75/264) received vancomycin plus piperacillin-tazobactam and were matched with 64 controls. There were no differences in gestational age or birth weight between cases and controls [688±160 vs. 689±162 grams (p = 0.99), and 24.7±1.8 vs. 24.7±1.6 weeks (p = 0.99) respectively]. There was no difference in the rate of sepsis between cases and controls [76%(55/72) vs. 64%(41/64) respectively, p = 0.11]. Infants exposed to vancomycin plus piperacillin-tazobactam had a higher percentage of concomitant use of vasopressors and amphotericin. To adjust for confounders, a logistic regression analysis was conducted with AKI as the dependent variable. Use of vasopressors and vancomycin plus piperacillin-tazobactam were the only risk factors associated with AKI with an adjusted OR (95%CI) of 4.08 (1.90-8.74), p <  0.001; and 2.87 (1.26-6.53), p = 0.01 respectively.

CONCLUSION

The use of vancomycin plus piperacillin-tazobactam in ELBW infants is associated with an increased risk for AKI.

Postnatal glucocorticoid use impacts renal function in VLBW neonates

BACKGROUND

Preterm neonates often require glucocorticoids to manage refractory hypotension, prevent, and treat bronchopulmonary dysplasia. We have investigated the effect of cumulative dose and duration of glucocorticoids on blood pressure and renal function in VLBW infants.

METHODS

In this retrospective cohort study, medical records of infants (GA ≤ 35 weeks) born January 2015 to December 2019 were reviewed to extract demographic and clinical characteristics, dose and duration of steroids, blood pressure (BP), and creatinine at the time of discharge from the neonatal intensive care unit.

RESULTS

Two hundred and eighty-three neonates with average GA (28 ± 3 weeks) and birthweight (1060±381 g). Twenty-eight percent (33/116) of infants who received postnatal steroids developed hypertension versus 16% (27/167) of controls (OR = 2.0, p = 0.011). There was a correlation between the cumulative dosage of postnatal steroids and systolic BP (R² = 0.06, p < 0.001). With increasing steroid dose and total steroid days, there was a significant increase in creatinine clearance at the time of discharge (R² = 0.13, p < 0.001; R² = 0.13, p < 0.001, respectively).

CONCLUSIONS

Cumulative dose of postnatal steroids and duration of use is associated with increased systolic BP in premature infants. Postnatal steroids should be used prudently to prevent long-term cardiovascular and renal morbidity.

IMPACT

Preterm neonates are exposed to a high dose of glucocorticoids during their neonatal intensive care stay. The dose and duration of use of postnatal glucocorticoids was associated with significant increase in blood pressure at the time of discharge in preterm neonates. Postnatal glucocorticoid use is associated with improved creatinine clearance likely due to a state of hyperfiltration and may lead to chronic kidney disease later in life. Postnatal glucocorticoids should be used prudently in this highly vulnerable population.

Furosemide Safety in Preterm Infants at Risk for Bronchopulmonary Dysplasia: A Randomized Clinical Trial

OBJECTIVE

To evaluate the safety of furosemide in preterm infants at risk of developing bronchopulmonary dysplasia (BPD).; Study design This multi-center, randomized, dose-escalating, placebo-controlled trial enrolled infants born <29 weeks gestational age at 7-28 days postnatal age and at risk for BPD. Infants were randomized 3:1 (furosemide:placebo) into 2 cohorts with escalating doses of furosemide to a maximum of 1 mg/kg intravenous (IV; or 2 mg/kg enteral) every 24 hours (cohort 1; n=40) or 1 mg/kg IV (or 2 mg/kg enteral) every 6 hours (cohort 2; n=40) for 28 days. The primary outcome effect of furosemide on total adverse events (AEs) and secondary outcomes BPD, death, hearing loss, serum electrolyte AEs, and nephrocalcinosis were estimated using logistic regression adjusted for gestational age.

RESULTS

We found 293 AEs in 74/80 (93%) infants, including 223 AEs among 56/61 (92%) infants who received furosemide and 70 AEs among 18/19 (95%) infants who received placebo (P>0.99). Adjusted analysis among all groups showed no difference in the odds of having moderate-to-severe BPD or death at 36 weeks post-menstrual age (P=0.32), hearing loss (P=0.78), or nephrocalcinosis (P=0.39). For serum electrolyte AE, odds ratio (furosemide vs placebo) was 4.46 (95% CI, 1.06-21.70; P=0.048) for cohort 1 and 7.89 (95% CI, 1.50-61.91; P=0.023) for cohort 2.

CONCLUSIONS

In preterm infants, furosemide did not increase overall incidence of AEs, hearing loss, or nephrocalcinosis, but did increase the incidence of electrolyte abnormalities. Furosemide given for 28 consecutive days was not associated with a difference in moderate-to-severe BPD or death at 36 weeks post-menstrual age.

CLINICALTRIALS

GOV: NCT02527798.