Family functioning, burden and parenting stress 2 years after very preterm birth

Background

Examining rates of difficulties in family functioning following very preterm birth has been a relatively neglected area of research.

Aims

To examine family functioning, burden and parenting stress in families with very preterm compared with term born children, and investigate influences of parental mental health problems and child neurodevelopmental disability on family outcomes in families with preterm children.

Study design

Participants were 184 very preterm and 71 term children and their parents. Parents completed the Family Assessment Device, Parenting Stress Index and Impact on Family questionnaires when their children were 2 years old (corrected for prematurity). Parental mental health and social risk information were also collected. Children were assessed for neurodevelopmental disability.

Results

Families with very preterm children reported poorer family functioning (p = .03) compared with families with term born children, with less evidence for differences between families with very preterm and term born children in parenting stress and family burden. Within very preterm families, parental mental health problems were associated with higher levels of parenting stress (p = .001), and parents of children with a neurodevelopmental disability were more likely to report higher family burden (p = .04).

Conclusions

For families with very preterm children, parental mental health symptoms and child neurodevelopmental disability may identify families at risk of greater stress and burden who may benefit from additional support.     

Fetal general movements and brain sonography in a population at risk for preterm birth

Background

General movements (GMs) assessed three months post term are related to brain injury and neurological outcome.

Aims

To study GMs in fetuses and their predictive value for echogenicity changes in the fetal brain.

Study design

Prospective study of fetal GMs (classified as normal or abnormal) and echogenicity changes in the periventricular, basal ganglia/thalami area, and ventricular system (classified as absent, mild or moderate).

Subjects

121 fetuses from pregnancies affected by hypertensive disorders and/or preterm labour, at risk for preterm birth (26-34 weeks gestational age).

Outcome measures

Prevalence of abnormal GMs, GM parameters (amplitude, speed and complexity), and moderate echogenicity changes in the fetal brain (periventricular ≥ IB, intraventricular grade II/III, and basal ganglia/thalamus locally increased). Predictive values of GMs for clinical parameters and moderate echogenicity changes.

Results

GMs were abnormal in 58%, with amplitude affected in 96%, and speed and complexity in 59%. Abnormal GMs correlated with oligohydramnios (p = 0.002) and hypertensive disorders (p = 0.015). Echogenicity changes of the brain were absent, mild and moderate in 27%, 39% and 31%, respectively. The sensitivity of GMs for moderate echogenicity changes in the three areas combined was 0.65, and the periventricular area 0.85, specificity both 0.44, negative predictive values 0.73 and 0.96 respectively.

Conclusions

Qualitative abnormal GMs are frequent in fetuses of compromised pregnancies, and correlate with hypertensive disorders and oligohydramnios. The amplitude of GMs was most frequently affected. Abnormal GMs relate to moderate echogenicity changes especially in the periventricular area of the fetal brain, while normal GMs predict absence of moderate echogenicity changes.     

The quality of fetal arm movements as indicators of fetal stress

Background

Although a number of studies have found that maternal stress affects the fetus, it is unclear whether jerky fetal movements observed on ultrasound scans are indicative of fetal stress, or whether they are part of normal development.

Aims

The present study was designed to examine the relationship between jerky fetal arm movements in relation to fetal age and stress.

Methods

Video recordings were made of routine ultrasound scans of 57 fetuses (age range 8 to 33 weeks) classified into three age groups: 1st trimester (8-12 weeks, N = 9), 2nd trimester (13-24 weeks, N = 38), and 3rd trimester (26-33 weeks, N = 10). Following previous research on stress behaviour in neonates, a fetal index of stress was derived from frequency of hiccup, back arch and rhythmical mouthing.

Results

Results indicated that while stress level was unrelated to fetal age, jerkiness of arm movements was significantly associated with the fetal stress index but not age.

Conclusions

Our findings suggest that jerky arm movements in fetuses are suggestive of fetal stress.     

Gender-related effects of prenatal administration of estrogen and progesterone receptor antagonists on VEGF and surfactant-proteins and on alveolarisation in the developing piglet lung

Background

Vascular endothelial growth factor (VEGF) is essential for embryonic lung development and has been shown to be regulated by estradiol (E2) and progesterone (P).

Aim

To investigate the effects of prenatal E2 and P withdrawal by specific receptor antagonists on the mRNA expression of VEGF, surfactant proteins (SP-B and SP-C) and on alveolarisation in lung tissue of male and female pig fetuses.

Methods

Fetuses from 10 sows were randomized to receive either both an intramuscular injection of the E2 receptor blocker ICI 182.780 and the P receptor blocker RTI 3021-022 (ICI + RTI, n = 5) or a placebo injection (n = 5) at 90 days of gestation (DOG, 115 = term). After delivery by cesarean section on 114 DOG, tissue of the left lingula of the piglet's lung (28 placebo, 26 ICI + RTI) was obtained to determine the mRNA expression of VEGF, SP-B and SP-C. Lungs from 15 placebo and 14 ICI + RTI group piglets were removed and alveolar counts performed.

Results

The ICI + RTI group showed significantly lower SP-C mRNA expression and alveolar counts compared to the placebo group (p = 0.04 and 0.03, respectively). Diminished alveolarisation in the ICI + RTI group was mainly due to the reduction of alveolar counts in male piglets (p = 0.02). Within the placebo group VEGF and SP-B mRNA expression in male piglets were significantly lower compared to female piglets (p = 0.01 and 0.004, respectively). ICI + RTI treatment abolished this gender-related difference.

Conclusion

Estradiol and P antagonism affected gender-related differences of key proteins for pulmonary function and development and especially in males was associated with diminished alveolarisation.     

No short-term benefits of antenatal corticosteroid treatment in severely preterm growth restricted fetuses: A case-control study

Background

Antenatal corticosteroid administration to premature, growth restricted fetuses may not be beneficial and even have adverse effects on neonatal outcome.

Aims

To determine if preterm growth restricted fetuses benefit from antenatal corticosteroids.

Study design

Retrospective cohort study.

Methods

All singleton pregnancies with growth restricted fetuses delivered at our department before 34 weeks' gestation or weighing less than 1500 g, between January 2001 and December 2005, were retrospectively reviewed. Neonatal outcome was compared between growth restricted fetuses (defined as abnormal flow patterns in umbilical and middle cerebral arteries) that received antenatal CST (CST group) and those who did not receive antenatal CST (no CST group). The administration of CST appeared to be quasi randomized.

Results

A total of 88 pregnancies fulfilled the inclusion criteria (CST group, n = 54; no CST group, n = 34). The incidence of neonatal respiratory distress syndrome in the CST and no CST group was 42% (22/54) and 50% (17/34), respectively (p = 0.44). Neonatal mortality in the CST and no CST group was 9% (5/54) and 12% (4/34), respectively (p = 0.73). The prevalence of adverse neonatal outcome (neonatal mortality, major neonatal morbidity or severe cerebral lesions) in the CST and no CST group was 28% (15/54) versus 24% (8/34), (p = 0.62).

Conclusions

Administration of CST to growth restricted preterm fetuses does not appear to be beneficial with respect to short term neonatal outcome.     

Leptin determination in colostrum and early human milk from mothers of preterm and term infants

Background

Leptin is involved in the regulation of food intake and energy expenditure and is therefore important for growth and brain development. Analytical methods used for leptin measurement in human milk differ widely in the literature and yield varying results.

Aims

To compare different preparation methods for the analysis of leptin in human milk and to investigate the leptin levels in colostrum and mature human milk from mothers of preterm or term infants.

Methods

Mothers delivering a preterm (n = 37) or a term infant (n = 40) were recruited for a prospective study and were ask to collect breast milk on the 3rd and 28th day of lactation. Leptin, protein and fat concentrations were analysed. Clinical data of mother and child were recorded prospectively.

Results

Skim milk was most appropriate for leptin analysis. Human milk leptin concentrations did not differ between preterm and term human milk. In term milk, leptin concentration on day 28 was lower than on day 3 (p < 0.05). Milk leptin levels on the 3rd and 28th day were positively correlated with mothers' body mass index, but not with fat content in milk.

Conclusion

Skim milk was the most stabile preparation for leptin analysis. Preterm and term human milk contain leptin in equal concentrations. Human milk leptin depends on mothers' body mass index.     

Prenatal depression restricts fetal growth

Objective

To identify whether prenatal depression is a risk factor for fetal growth restriction.

Methods

Midgestation (18-20 weeks GA) estimated fetal weight and urine cortisol and birthweight and gestational age at birth data were collected on a sample of 40 depressed and 40 non-depressed women. Estimated fetal weight and birthweight data were then used to compute fetal growth rates.

Results

Depressed women had a 13% greater incidence of premature delivery (Odds ratio (OR) = 2.61) and 15% greater incidence of low birthweight (OR = 4.75) than non-depressed women. Depressed women also had elevated prenatal cortisol levels (p = .006) and fetuses who were smaller (p = .001) and who showed slower fetal growth rates (p = .011) and lower birthweights (p = .008). Mediation analyses further revealed that prenatal maternal cortisol levels were a potential mediator for the relationship between maternal symptoms of depression and both gestational age at birth and the rate of fetal growth. After controlling for maternal demographic variables, prenatal maternal cortisol levels were associated with 30% of the variance in gestational age at birth and 14% of the variance in the rate of fetal growth.

Conclusion

Prenatal depression was associated with adverse perinatal outcomes, including premature delivery and slower fetal growth rates. Prenatal maternal cortisol levels appear to play a role in mediating these outcomes.     

Reduced cerebellar diameter in very preterm infants with abnormal general movements

Background

Abnormal General Movements (GMs) early in life are predictive of later neuromotor deficits and are related to white matter abnormalities on magnetic resonance imaging (MRI). However, other structural correlates of abnormal GMs have not been defined.

Aims

The objective of this study was to explore brain-metrics (linear brain measurements on MRI representative of 3-D brain volumes) at term as a predictor of abnormal GMs at 1 and 3 months' corrected age in preterm infants. It was hypothesized that abnormal GMs would be related to reduced brain-metrics in primary motor areas, namely the cerebellum and parietal lobes.

Study design

Eighty three preterm infants (< 30 weeks' gestational age) were scanned at term-equivalent age. MRI was assessed for white matter abnormality and brain-metrics in six predefined brain regions (i.e. bifrontal, biparietal, lateral ventricles and transverse cerebellar diameters, and inter-hemispheric distance).

Outcome measures

At 1 and 3 months' corrected age infants' GMs were assessed from video-taped footage and rated as normal or abnormal using standardized methodology.

Results

At 1 month, 63% (n = 52) of infants had abnormal GMs with no association between any of the brain-metrics and abnormal GMs. At 3 months, 23% (n = 18) of infants had abnormal GMs (absent fidgety movements n = 18; abnormal fidgety movements n = 0). Reduced bifrontal, biparietal, and cerebellar transverse diameters, along with an increase in lateral ventricle sizes were associated with an increased risk of abnormal GMs at 3 months' corrected age. After controlling for white matter abnormality and grade III/IV intraventricular haemorrhage, only the cerebellar transverse diameter was predictive of abnormal GMs at 3 months.

Conclusions

Reduced cerebellar diameter at term equivalent age is related to abnormal GMs at 3 months' corrected age, independent of white matter abnormality and intraventricular haemorrhage.     

A prospective study on intrauterine cannabis exposure and fetal blood flow

Background

Cannabis is commonly used among pregnant women. It is unclear whether cannabis exposure causes hemodynamic modifications in the fetus, like tobacco does.

Aims

This study aims to ascertain fetal blood redistribution due to intrauterine cannabis exposure.

Methods

This study was embedded in the Generation R Focus Study, a population-based cohort of parents and children followed from pregnancy onwards. In late pregnancy, fetal hemodynamics was assessed with ultrasound measurements in cannabis-exposed and non-exposed fetuses. Pregnant women reported about substance use during pregnancy. A distinction was made between continued cannabis use (n = 9), cannabis use only in early pregnancy (n = 14), continued tobacco use (n = 85), tobacco use only in early pregnancy (n = 92), and no tobacco or cannabis use during pregnancy (n = 85).

Results

Continued cannabis use was associated with an increased pulsatility and resistance index of the uterine artery, while discontinued cannabis use was associated with a decreased pulsatility, and resistance index, as compared to controls. Additionally, continued cannabis exposure resulted in a significantly higher uterine pulsatility index and uterine resistance index compared to tobacco exposure. Continued cannabis use was found to be associated with a smaller aortic diameter, as well. No association between intrauterine cannabis exposure and the fetal cerebral vascular system was found.

Conclusions

Our findings suggest that intrauterine cannabis exposure was associated with changes in hemodynamic programming of the vascular system of the fetus in late pregnancy mainly due to tobacco exposure, but intrauterine cannabis exposure did demonstrate a specific effect on the uterine blood flow.     

Aerobic exercise during pregnancy influences fetal cardiac autonomic control of heart rate and heart rate variability

Background

Previous studies using ultrasound technology showed that fetal heart rate (HR) may be responsive to maternal aerobic exercise. Although it is recognized that cardiac autonomic control may be influenced by the intrauterine environment, little is known about how maternal exercise affects fetal heart development.

Aims

This study tested the hypothesis that regular maternal exercise throughout gestation influences fetal cardiac autonomic control of HR and heart rate variability (HRV) when compared to fetuses of non-exercising women.

Study design

Magnetocardiograms (MCGs) were recorded using a dedicated fetal biomagnetometer at 28, 32 and 36 weeks gestational age (GA) from 26 regularly exercising (> 30 min of aerobic exercise, 3× per week) and 35 healthy, non-exercising pregnant women. Fetal MCG was isolated and normal R-peaks were marked to derive fetal HR and HRV in the time and frequency domains. We applied a mixed-effects model to investigate the effects of exercise, GA and fetal activity state.

Results

At 36 weeks GA, during the active fetal state, fetal HR was significantly lower in the exercise group (p = < 0.0006). Post-hoc comparisons showed significantly increased HRV in the exercise group during the active fetal state at 36 weeks GA for both time and frequency domain measures.

Conclusion

These results indicate that regular maternal exercise throughout gestation results in significantly lower fetal HR and increased HRV.     

Long-term neurological outcome of term-born children treated with two or more anti-epileptic drugs during the neonatal period

Background

Neonatal seizures may persist despite treatment with multiple anti-epileptic drugs (AEDs).

Objective

To determine in term-born infants with seizures that required two or more AEDs, whether treatment efficacy and/or the underlying disorder were related to neurological outcome.

Design/methods

We included 82 children (born 1998-2006) treated for neonatal seizures. We recorded mortality, aetiology of seizures, the number of AEDs required, achievement of seizure control, and amplitude-integrated-EEG (aEEG) background patterns. Follow-up consisted of an age-adequate neurological examination. Surviving children were classified as normal, having mild neurological abnormalities, or cerebral palsy (CP).

Results

Forty-seven infants (57%) had status epilepticus. The number of AEDs was not related to neurological outcome. Treatment with three or four AEDs as opposed to two showed a trend towards an increased risk of a poor outcome, i.e., death or CP, odds ratio (OR) 2.74; 95% confidence interval (CI) 0.98-7.69; P = .055. Failure to achieve seizure control increased the risk of poor outcome, OR 6.77; 95%-CI 1.42-32.82, P = .016. Persistently severely abnormal aEEG background patterns also increased this risk, OR 3.19; 95%-CI 1.90-5.36; P < .001. In a multivariate model including abnormal aEEG background patterns, failure to achieve seizure control nearly reached significance towards an increased risk of poor outcome, OR 5.72, 95%-CI 0.99-32.97, P = .051. We found no association between seizure aetiology and outcome.

Conclusions

In term-born infants with seizures that required two or more AEDs outcome was poorer if seizure control failed. The number of AEDs required to reach seizure control and seizure aetiology had limited prognostic value.     

Chronic rhinosinusitis in young children differs from adults: a histopathology study

Objective

A histopathologic study of children with chronic rhinosinusitis (CRS) was undertaken to compare the sinus mucosa in pediatric and adult CRS.

Study design

CRS has been defined as persistent or recurrent sinusitis symptoms for ≥12 weeks despite conventional medical therapy, with abnormal computed tomography of the maxillary sinuses. Maxillary mucosal biopsies were obtained from pediatric CRS subjects for inflammatory cell and morphologic studies. Archival sinus mucosal tissues from adults with CRS were used as histologic controls. Sinus lavages were performed on children with and without CRS for microbiologic studies.

Results

Sinus mucosal biopsies were obtained from 19 children with CRS (median age, 3.0 years; range 1.4-8.2 years). Pediatric CRS biopsies, as compared with adult CRS controls, had a higher density of submucosal lymphocytes (median 469 versus 294 cells/mm² per 5 high-power fields [HPF]; P = .02), lower density of submucosal eosinophils (medians 13 versus 82 cells/mm² per 5 HPF; P = .01), thinner and more intact epithelium (P = .01 and .07, respectively), thinner basement membranes (P = .002), and fewer submucosal mucous glands (P = .004).

Conclusion

The sinus mucosa of young children with CRS has less eosinophilic inflammation, basement membrane thickening, and mucus gland hyperplasia characteristic of adult CRS.     

An infant and child feeding index is associated with child nutritional status in rural China

Background

Some researchers have developed child feeding indices to summarize child feeding practices so that they can compare child feeding practices across countries and monitor changes over time within a given country.

Aims

An adapted version of the infant and child feeding index (ICFI) developed by Ruel and Menon was used to examine its association with nutritional status of infants living in a rural community in China.

Methods

A cross-sectional survey of 501 children aged 6-11 mo was conducted with their mothers in 8 townships between May 2006 and March 2007. ICFI was developed based on 24-h dietary recall and food frequency information. The associations between ICFI and anthropometric indices including length-for-age (LAZ), weight-for-age (WAZ), and weight-for-length (WLZ) Z-scores were examined separately. General linear regression models were used to adjust for potential confounders including the children's, parents' and households' sociodemographic characteristics.

Results

The ICFI was associated with both WAZ (adjusted WAZ means: 0.39, 0.47, and 0.54 for the 1st, 2nd, and 3rd tercile, respectively, P < 0.05) and WLZ (adjusted WLZ means: 0.47, 0.74, and 0.79 for the 1st, 2nd, and 3rd tercile, respectively, P < 0.05). But it was not associated with children's LAZ. Among the components of ICFI, dietary diversity, meal frequency and bottlefeeding were positively associated with the children's anthropometric indices.

Conclusions

ICFI and its components could be used to assess effect of complementary feeding practices on child growth.     

The relation between umbilical cord characteristics and the outcome of external cephalic version

Background

Umbilical cords of fetuses in breech presentation differ in length and coiling from their cephalic counterparts and it might be hypothesised that these cord characteristics may in turn affect ECV outcome.

Aim

To investigate the relation between umbilical cord characteristics and the outcome of external cephalic version (ECV).

Study design

Prospective cohort study.

Subjects

Women (> 35 weeks gestation) with a singleton fetus in breech presentation, suitable for external cephalic version. Demographic, lifestyle and obstetrical parameters were assessed at intake. ECV success was based on cephalic presentation on ultrasound post-ECV. Umbilical cord length (UCL) and umbilical coiling index (UCI) were measured after birth.

Outcome measure

The relation between umbilical cord characteristics (cord length and coiling) and the success of external cephalic version.

Results

ECV success rate was overall 79/146 (54%), for multiparas 37/46(80%) and for nulliparas 42/100 (42%). Multiple logistic regression showed that UCL (OR: 1.04, CI: 1.01-1.07), nulliparity (OR: 0.20, CI: 0.08-0.51), frank breech (OR: 0.37, 95% CI: 0.15-0.90), body mass index (OR: 0.85, CI: 0.76-0.95), placenta anterior (OR: 0.27, CI: 0.12-0.63) and birth weight (OR: 1.002, CI: 1.001-1.003) were all independently related to ECV success.

Conclusions

Umbilical cord length is independently related to the outcome of ECV, whereas umbilical coiling index is not.     

Changes in spectral power of fetal heart rate variability in small-for-gestational-age fetuses are associated with fetal sex

Background

Little is known about the influences of fetal weight and sex on spectral analysis of fetal heart rate (FHR) variability.

Aim

The study aims to assess whether there are differences in spectral power of FHR variability according to fetal weight and sex during labor.

Study design

Case–control study. A total of 414 singleton term deliveries without fetal acidemia were divided into small-for-gestational-age (SGA) (n = 29) and non-SGA (n = 385) groups. Analyses were performed separately according to fetal sex.

Subjects

FHR recordings obtained with cardiotocography during the last 2 h of labor preceding delivery.

Outcome measures

Our outcome measures include spectral power of FHR variability.

Results

For the male group, SGA fetuses had significantly lower values for low, movement, high, and total frequencies of spectral power compared with non-SGA fetuses (all P < 0.005). Normalized low frequency (LFn) was significantly higher, and normalized high frequency (HFn) was significantly lower in SGA fetuses compared with non-SGA fetuses (all P < 0.005). In contrast, for the female group, there were no significant differences in any of the indices of spectral power between the SGA and non-SGA fetuses. In addition, SGA males had significantly higher LFn spectral power and lower HFn spectral power compared to SGA females (P = 0.016, and 0.041, respectively).

Conclusions

SGA males have decreased spectral power of FHR variability compared with non-SGA males during labor. However, there are no differences between SGA and non-SGA female fetuses. It is important in the clinical setting to take fetal weight and sex into account during FHR monitoring using spectral analysis.     

The behavioral pain response to heelstick in preterm neonates studied longitudinally: Description, development, determinants, and components

Objectives

Preterm infants often experience multiple painful procedures during their stay in neonatal intensive care units (NICUs). The objectives of this study were to evaluate behavioral responses to heelstick in preterm newborns, characterize developmental changes and the effects of other demographic and clinical variables on the pain response, and estimate the contributions of individual Neonatal Infant Pain Scale (NIPS) behaviors to the summary pain score.

Methods

A longitudinal study was conducted to evaluate the behavioral responses of 35 preterm newborns to multiple heelstick procedures during their stay in the NICU. Sixty-one video recordings of blood collection by heel lance were evaluated for behavioral pain response using the NIPS. Generalized linear mixed models were calculated to address the study objectives.

Results

The increases in NIPS scores from the baseline to the blood draw were highly significant (mean baseline score = 3.34, mean blood draw score = 5.45, p < 0.001). The newborns' pain responses increased an average of 0.23 points on the NIPS scale each week (p = 0.002). Lower NIPS scores during the heelstick procedure were associated with four clinical variables: younger post-menstrual age at birth, lower birthweight, mechanical ventilation, and longer length of stay in the NICU. Crying, arousal state, and facial grimace contributed more than 85% of the increase in NIPS scores during the heelstick procedure.

Discussion

While behavioral responses to pain are attenuated in young, severely ill preterm newborns, they can be reliably detected. The most robust pain behaviors are crying, changes in arousal state, and facial grimacing.     

Changes in physiological and behavioural pain indicators over time in preterm and term infants at risk for neurologic impairment

Background

Approximately 10% of infants admitted to a Neonatal Intensive Care Unit (NICU) are at risk for Neurological Impairment (NI). While we have limited knowledge on the influence of NI risk on pain responses, we have no knowledge of how these responses change over time.

Objective

To compare physiological and behavioural pain responses of infants at three levels of NI risk during the NICU neonatal period (Session 1) and at 6 months of age (Session 2).

Design/methods

Prospective observational design with 149 preterm and term infants at high (Cohort A, n = 54), moderate (Cohort B, n = 45) and mild (Cohort C, n = 50) risks for NI from 3 Canadian tertiary level NICUs. Infants were observed in the NICU during 3 standardized phases of a heel lance: baseline, stick and return-to-baseline. At 6 months, infants were observed during the same three phases during an intramuscular immunization injection. Physiological (heart rate, oxygen saturation) and behavioural (9 facial actions, cry) responses were continuously recorded.

Results

A significant interaction of Phase by Session was found with less total facial activity observed during Session 2 (all p values < 0.04). A significant interaction for Session by Cohort was found, showing that infants in Cohort A had significantly more change from baseline-to-stick phase for brow bulge, eye squeeze, nasolabial furrow and open lips between sessions with less facial actions demonstrated at Session 2 (all p < 0.02). There were significantly lower mean and minimum heart rate (all p < 0.02) and higher minimum and maximum oxygen saturation (p < 0.04) at Session 2. Significantly higher mean and minimum fundamental cry frequencies (pitch) in Cohort B (p < 0.04) were found in Session 1. Cohort A had significantly longer cry durations, but no significant differences in cry dysphonation.

Conclusions

Behavioural and physiological infant pain responses were generally diminished at 6 months of age compared to those in the neonatal period with some differences between NI risk groups in cry responses. Future exploration into the explanation for these differences between sessions and cohorts is warranted.     

Normalized spectral power of fetal heart rate variability is associated with fetal scalp blood pH

Background

Spectral power of fetal heart rate variability is related to fetal condition. Previous studies found an increased normalized low frequency power in case of severe fetal acidosis.

Aims

To analyze whether absolute or normalized low or high frequency power of fetal heart rate variability is associated with fetal scalp blood pH.

Study design

Prospective cohort study, performed in an obstetric unit of a tertiary care teaching hospital.

Subjects

Consecutive singleton term fetuses in cephalic presentation that underwent one or more scalp blood samples, monitored during labour using ST-analysis of the fetal electrocardiogram. Ten-minute continuous beat-to-beat fetal heart rate segments, preceding the scalp blood measurement were used.

Outcome measures

Absolute and normalized spectral power in the low frequency band (0.04-0.15 Hz) and in the high frequency band (0.4-1.5 Hz).

Results

In total 39 fetal blood samples from 30 patients were studied. We found that normalized low frequency and normalized high frequency power of fetal heart rate variability is associated with fetal scalp blood pH. The estimated ß of normalized low frequency power was −0.37 (95% confidence interval −0.68 to −0.06) and the relative risk was 0.69 (95% confidence interval 0.51-0.94). The estimated ß of normalized high frequency power was 0.33 (95% confidence interval 0.01-0.65) and the relative risk was 1.39 (95% confidence interval 1.01-1.92).

Conclusions

Normalized low and normalized high frequency power of fetal heart rate variability is associated with fetal scalp blood pH.     

Antenatal fetal VEGF therapy to promote pulmonary maturation in a preterm rabbit model

Aim

To assess the effects of fetal tracheal administration of VEGF on pulmonary maturation in a preterm rabbit model.

Methods

On day 26 (term = 31 days), fetal rabbits received recombinant rat VEGF (30 µg in 70 µL normal saline) or placebo (normal saline 70 µL) intratracheally, with or without subsequent tracheal occlusion. Non-operated littermates served as internal controls. Fetuses were harvested on day 28 for morphometric study of the lungs or for mechanical ventilation and measurement of lung mechanics. In total, 96 fetuses from 42 does were used, 47 for ventilation and 49 for morphometry.

Results

In fetuses receiving intratracheal VEGF, an increase in immunoreactivity for Flk-1 was observed throughout the lung parenchyma. Tracheal occlusion (TO) adversely affected pulmonary mechanics as compared to un-occluded controls. That effect is partly reversed by intratracheal VEGF. Intratracheal injection of VEGF without tracheal occlusion improves lung mechanics but no more than what was observed in placebo injected controls.

Conclusion

Antenatal intratracheal VEGF administration was associated with an increase in Flk-1 immunoreactivity. It also improves lung mechanics, however more so when the trachea is occluded. Without TO, the effects were comparable to placebo controls.