Early intervention leads to long-term developmental improvements in very preterm infants, especially infants with bronchopulmonary dysplasia

AIM

Various early intervention programmes have been developed in response to the high rate of neurodevelopmental problems in very preterm infants. We investigated longitudinal effects of the Infant Behavioral Assessment and Intervention Program on cognitive and motor development of very preterm infants at the corrected ages of six months to five and a half years.

METHODS

This randomised controlled trial divided 176 infants with a gestational age <32 weeks or birthweight <1500 g into intervention (n = 86) and control (n = 90) groups. Cognitive development and motor development were assessed with the Bayley Scales of Infant Development at the CAs of six, 12 and 24 months and at five and a half years with the Wechsler Preschool and Primary Scale of Intelligence and the Movement Assessment Battery for Children.

RESULTS

We found significant longitudinal intervention effects (0.4 SD, p = 0.006) on motor development, but no significant impact on cognitive development (p = 0.063). Infants with bronchopulmonary dysplasia showed significant longitudinal intervention effects for cognitive (0.7 SD; p = 0.019) and motor (0.9 SD; p = 0.026) outcomes. Maternal education had little effect on intervention effects over time.

CONCLUSION

The Infant Behavioral Assessment and Intervention Program led to long-term developmental improvements in the intervention group, especially in infants with BPD.

The effect of preimplantation genetic screening on neurological, cognitive and behavioural development in 4-year-old children: follow-up of a RCT

STUDY QUESTION

Does embryo biopsy inherent to preimplantation genetic screening (PGS) affect neurological, cognitive and behavioural development of 4-year-old children?

SUMMARY ANSWER

PGS does not seem to affect neurological, cognitive and behavioural development of 4-year-old singletons; however, our data suggest that it may be associated with altered neurodevelopment in twins.

WHAT IS KNOWN ALREADY

Evidence concerning the safety of PGS on neurodevelopmental outcome in offspring is scarce. The present study provides information on neurodevelopmental, cognitive and behavioural outcome of 4-year-old PGS offspring.

STUDY DESIGN, SIZE, DURATION

A prospective, assessor-blinded follow-up study of children born to women who participated in a multi-centre RCT on the effect of IVF with or without PGS.

PARTICIPANTS/MATERIALS, SETTING, METHODS

At 4 years, 49 children (31 singletons, 9 sets of twins) born following IVF with PGS and 64 children (42 singletons, 11 sets of twins) born following IVF without PGS (controls) were assessed (post-natal attrition 18%). Neurological development was evaluated with the standardized, age-specific and sensitive neurological examination according to Hempel, resulting in a neurological optimality score (NOS), a fluency score and the rate of adverse neurological outcome. Primary outcome was the fluency score, as fluency of movements is easily reduced by subtle dysfunction of the brain. Cognitive development was evaluated with the Kaufman Assessment Battery for Children; behavioural development was evaluated with the Child Behavior Checklist. The effect of PGS was analysed with a mixed effects model.

MAIN RESULTS AND THE ROLE OF CHANCE

Based on the intention to treat analysis, neurodevelopmental outcome of PGS children was similar to that of controls. However, additional analyses indicated that PGS affected neurodevelopmental outcome of twins in a different way than that of singletons. The fluency score of singletons born following PGS was similar to that of control singletons [mean values, 95% confidence intervals (CIs): 12.2 (11.5;12.8) and 12.2 (11.6;12.8)], respectively, P = 0.977) that was also true for the other neurodevelopmental parameters. The fluency score of PGS twins was significantly lower than that of control twins [mean values, 95% CIs: 10.6 (9.8;11.3) and 12.3 (11.5;13.1)], respectively, P = 0.001); the same was true for the NOS. In addition, PGS in twins was associated with a higher sequential intelligence quotient score. On the other hand, other neurodevelopmental parameters were similar for PGS twins and control twins. Post hoc sample size calculation for the primary outcome parameter, the fluency score, indicated that the study groups, including the subgroups of singletons and twins, were adequately powered.

LIMITATIONS, REASONS FOR CAUTION

We assessed singletons and twins who contributed to the generalizability of the study. A limitation of our study is the relative small size of our study groups and the selective dropout in both groups (dropouts PGS group: higher gestational age; control group: less well-educated parents). These preclude the conclusion that PGS per se is not associated with neurodevelopmental, cognitive and behavioural problems in singletons and the conclusion that PGS is associated with altered neurodevelopmental outcome in twins.

WIDER IMPLICATIONS OF THE FINDINGS

The need for careful long-term monitoring of children born following embryo biopsy remains, as it is still applied in the form of PGD and it is still unknown whether embryo biopsy affects long-term neurodevelopmental outcome.

Parental psychological distress and anxiety after a successful IVF/ICSI procedure with and without preimplantation genetic screening: follow-up of a randomised controlled trial

BACKGROUND

Infertility treatment has an acknowledged psychological impact on women and their partners; however, information about the development of parental well-being after child birth is inconclusive. Preimplantation genetic screening (PGS) has been suggested to increase the efficacy of infertility treatments, but the effect it may have on parental well-being is unknown.

AIM

To evaluate parental distress and anxiety at one and two years after successful infertility treatment and to explore variables that might affect parental outcome, including PGS and child behaviour.

STUDY DESIGN

Follow-up of a randomised controlled trial (RCT) on the efficacy of PGS.

SUBJECTS

Parents (n=101) that successfully underwent IVF/ICSI with or without PGS.

OUTCOME MEASURES

At one and two years, parental distress and anxiety were assessed with the General Health Questionnaire 30 and State Trait Anxiety Inventory, respectively. At two years, child development and behaviour were assessed with the Dutch Bayley Scales of Infant Development-II and the Child Behaviour Checklist 1½-5, respectively.

RESULTS

PGS had no effect on parental distress or anxiety. Child behaviour problems were associated with parental distress and anxiety. There was a main effect of time on parental distress, with distress levels decreasing over time.

CONCLUSIONS

We found no objection to PGS related to parental psychological distress and anxiety. When parental psychological problems are present after infertility treatment, the results of this study could be useful to support counselling.

Visual perception and visual-motor integration in very preterm and/or very low birth weight children: a meta-analysis

A range of neurobehavioral impairments, including impaired visual perception and visual-motor integration, are found in very preterm born children, but reported findings show great variability. We aimed to aggregate the existing literature using meta-analysis, in order to provide robust estimates of the effect of very preterm birth on visual perceptive and visual-motor integration abilities. Very preterm born children showed deficits in visual-spatial abilities (medium to large effect sizes) but not in visual closure perception. Tests reporting broad visual perceptive indices showed inconclusive results. In addition, impaired visual-motor integration was found (medium effect size), particularly in boys compared to girls. The observed visual-spatial and visual-motor integration deficits may arise from affected occipital-parietal-frontal neural circuitries.

Parenting stress in mothers after very preterm birth and the effect of the Infant Behavioural Assessment and Intervention Program

OBJECTIVE

Purpose of this study was to examine maternal parenting stress as a secondary outcome of the Infant Behavioural Assessment and Intervention Program (IBAIP).

METHODS

In a randomized controlled trial 86 very preterm infants and their parents were assigned to the intervention group and 90 to the control group. Maternal parenting stress was assessed with the Dutch version of the Parenting Stress Index at 12 and 24 months post term.

RESULTS

Mothers in the intervention group mothers assessed their infants as happier and less hyperactive/distractible compared with the control group mothers. However, mothers in the intervention group reported more feelings of social isolation.

CONCLUSIONS

The IBAIP appears to have made mothers more satisfied about their infants' mood and distractibility, but also may have evoked more feelings of social isolation. Next to long-term evaluation of the development in very preterm born children, follow-up on functioning of their parents is important.

Development and growth in very preterm infants in relation to NIDCAP in a Dutch NICU: two years of follow-up

AIM

To study development and growth in relation to newborn individualized developmental and assessment program (NIDCAP) for infants born with a gestational age of less than 30 weeks.

METHODS

Developmental outcome of surviving infants, 25 in the NIDCAP group and 24 in the conventional care group, in a prospective phase-lag cohort study performed in a Dutch level III neonatal intensive care unit (NICU) was compared. Main outcome measure was the Bayley scales of infant development-II (BSID-II) at 24 months corrected age. Secondary outcomes were neurobehavioral and developmental outcome and growth at term, 6, 12 and 24 months.

RESULTS

Accounting for group differences and known outcome predictors no significant differences were seen between both care groups in BSID-II at 24 months. At term age NIDCAP infants scored statistically significant lower on neurobehavioral competence; motor system (median [IQR] 4.8 [2.9-5.0] vs. 5.2 [4.3-5.7], p = 0.021) and autonomic stability (median [IQR] 5.7 [4.8-6.7] vs. 7.0 [6.0-7.7], p = 0.001). No differences were seen in other developmental outcomes. After adjustment for background differences, growth parameters were comparable between groups during the first 24 months of life.

CONCLUSION

At present, the strength of conclusions to be drawn about the effect of NIDCAP on developmental outcome or growth at 24 months of age is restricted. Further studies employing standardized assessment approaches including choice of measurement instruments and time points are needed.

A case of neonatal dural sinus malformation: clinical symptoms, imaging and neuropathological investigations

We report a case of neonatal dural sinus malformation already visible on antenatal ultrasound. This is a rare disease entity in infants and children. Clinical diagnosis was made by demonstrating a cranial murmur on auscultation; macrocrania and signs of progressive cardiac failure. Imaging studies as cerebral ultrasound, postnatal MRI scan and MR angiography demonstrated a large dural sinus malformation originating from the sagittal sinus with extensive arteriovenous fistulae. Due to the extent of the lesion, the existing ischemic brain damage and involvement of the torcular, no therapeutic options were available and the child died of irreversible cardiac failure. The diagnosis was confirmed with autopsy. We discuss the clinical presentation, imaging and neuropathological results and relate our findings to embryological data and the existing literature.

Individualized developmental care in a Dutch NICU: short-term clinical outcome

AIM

To compare the short-term clinical outcomes of Newborn Individualized Developmental Care and Assessment Program (NIDCAP) and conventional care.

METHODS

A prospective phase-lag cohort study was performed in a Dutch tertiary level neonatal intensive care unit (NICU). Infants born before 30 weeks of gestational age (GA) were included, 26 in the conventional and 25 in the NIDCAP group. Outcomes were respiratory status, cerebral ultrasound findings, growth and length of NICU stay.

RESULTS

At study entry, NIDCAP infants had a lower birth weight (mean [SD]: 1043 [191] vs. 1154 [174] g, p = 0.044), were more often small for GA (8 vs. 2, p = 0.038), had smaller head circumferences (mean [SD]: 25.1 [1.3] vs. 26.1 [1.8] cm, p = 0.041) and were less often multiples (6 vs. 14, p = 0.029) than conventional care infants. During NICU stay, more infants in the NIDCAP group developed pneumonia (9 vs. 3, p = 0.040) due to nosocomial infections. After adjustment for these differences, a decreased risk for more severe cerebral damage in favour of NIDCAP was seen (Odds ratio: 0.12, 95% CI: 0.03-0.46, p = 0.002). No differences were observed for the other outcomes.

CONCLUSIONS

We conclude with precaution that in this phase-lag cohort study NIDCAP may have resulted in less severe cerebral damage, but was not associated with other clinical outcomes. In light of these findings, NIDCAP deserves further exploration.

[The practice guideline 'Volume suppletion in critically-ill neonates and children up to the age of 18 years' of the Dutch Paediatric Association]

Hypovolaemia is the most common cause of circulatory failure in children. Treatment consists of volume suppletion with a crystalloid or colloid solution; which agent is the best in children is not clear. This evidence-based practice guideline formulates recommendations as to which fluid should be used for volume suppletion in critically-ill neonates and children up to the age of 18 years with hypovolaemia. Before the guideline development first-choice fluid for volume resuscitation was in 50% a colloid and in 50% a crystalloid solution for both neonatologists and paediatric intensivists. The neonatologists used human albumin as a priority, and the paeditric intensivists predominantly used a synthetic colloid. The guideline was developed on the basis of a comprehensive search and analysis of the literature according to the principles of evidence-based guideline development. The recommendations were formulated by a committee based on evidence from the literature and, when evidence from the literature was insufficient, on consensus after discussion in the committee. Since colloids are much more expensive than crystalloids and can give an anaphylactic reaction, their added value over crystalloids must be proven. In sick neonates and children, insufficient clinical trials have been done to reach the conclusion that colloids are more effective than crystalloids in hypovolaemia. A number of meta-analyses in adults revealed excess mortality in the group treated with albumin, but one recent, large, randomised study showed no difference in mortality. No added value could be demonstrated for the administration of synthetic colloids. On the basis of data from the literature and considerations regarding the applicability of evidence in adults to children and neonates, the side effects of resuscitation fluids, pathophysiology and costs, the first-choice fluid for neonates and children with hypovolaemia is isotonic saline. Albumin should not be used for the treatment of hypovolaemia. The volume to be administered and the infusion rate depend on the severity of the hypovolaemia and should be determined on an individual basis.

Effect of ventilation strategy and surfactant on inflammation in experimental pneumonia

This study explored, the inflammatory response during experimental pneumonia in surfactant-depleted animals as a function of ventilation strategies and surfactant treatment. Following intratracheal instillation of Group B streptococci (GBS), surfactant-depleted piglets were treated with conventional (positive-end expiratory pressure (PEEP) of 5 cmH2O, tidal volume 7 mL x kg(-1)) or open lung ventilation. During the latter, collapsed alveoli were recruited by applying high peak inspiratory pressures for a short period of time, combined with high levels of PEEP and the smallest possible pressure amplitude. Subgroups in both ventilation arms also received exogenous surfactant. Conventionally ventilated healthy animals receiving GBS and surfactant-depleted animals receiving saline served as controls. In contrast with both control groups, surfactant-depleted animals challenged with GBS and conventional ventilation showed high levels of interleukin (IL)-8, tumour necrosis factor (TNF)-alpha and myeloperoxidase in bronchoalveolar lavage fluid after 5 h of ventilation. Open lung ventilation attenuated this inflammatory response, but exogenous surfactant did not. Systemic dissemination of the inflammatory response was minimal, as indicated by low serum levels of IL-8 and TNF-alpha. In conclusion, the current study indicates that the ventilation strategy, but not exogenous surfactant, is an important modulator of the inflammation during Group B streptococci pneumonia in mechanically ventilated surfactant-depleted animals.

Assessment of the rectoanal inhibitory reflex in preterm infants with delayed meconium passage

BACKGROUND

There is an inverse relationship between gestational age, birth weight and the time of first neonatal bowel movement. The authors hypothesized that delayed passage of meconium might result from a delayed maturation of the recto-anal inhibitory reflex (RAIR) in premature infants.

OBJECTIVE

To evaluate whether the RAIR is absent in very preterm infants 28-32 weeks postmenstrual age with delayed meconium production.

STUDY DESIGN

Anorectal manometry was performed in 10 preterm infants (seven male) with delayed meconium production (no meconium in the first 48 hours). Median postmenstrual age was 30 weeks (28-31 weeks). Birth weight ranged from 780 to 1930 g (median, 1395 g). A micromanometric assembly (outer diameter, 2.0 mm) was used which incorporated a 1.5-cm-long sleeve sensor for measurement of resting anal sphincter pressure and relaxation. Four side-holes recorded anal and rectal pressures. Rectal distension was performed with direct air insufflation to elicit the RAIR.

RESULTS

The time from birth to passage of meconium ranged from 48 to 105 hours (median, 82 hours). The mean anal sphincter pressure, rectal pressure, and anal sphincter oscillation frequency were 22.0 +/- 5.0 mm Hg, 6.9 +/- 2.0 mm Hg, and 9.8 +/- 1.9/min, respectively. A normal RAIR was elicited in all infants.

CONCLUSION

Anorectal manometry recordings in premature infants with delayed passage of meconium showed normal anorectal pressures and a normal RAIR, suggesting that delayed meconium passage is not related to the absence of a RAIR.

Maturation of the rectoanal inhibitory reflex in very premature infants

OBJECTIVE

To characterize anal sphincter function in very premature infants < or =30 weeks' postmenstrual age (PMA) and to evaluate the time of maturation of the rectoanal inhibitory reflex (RAIR) by using a sleeve catheter.

STUDY DESIGN

Anorectal manometry was performed in 16 healthy neonates (nine girls) with a mean PMA of 29 weeks (range, 27-30 weeks) and a birth weight of 640 to 1590 g (median, 1220 g) with a micromanometric assembly (outer diameter, 2.0 mm). The assembly incorporated a 1.5-cm-long sleeve sensor for measurement of resting anal sphincter pressures and relaxation, and four side holes recorded anal and rectal pressures. Rectal distention was performed with direct air insufflation to elicit the RAIR.

RESULTS

The mean anal sphincter pressure, rectal pressure, and anal sphincter oscillation frequency were 24.5+/-11.4 mm Hg, 6.5+/-4.8 mm Hg, and 11.1+/-2.3/min, respectively. A normal RAIR could be elicited in 13 (81%) infants studied. In two infants, the RAIR could not be elicited because of a low anal sphincter pressure of only 5 mm Hg. In the other child, no RAIR was seen despite the repeated insufflation of at least 5 mL of air.

CONCLUSION

The majority (81%) of premature infants older than 26 weeks' PMA have normal anorectal pressures and a normal RAIR.

Postnatal thyroid hormone replacement in very preterm infants

Transient hypothyroxinemia occurs frequently in very preterm infants and is caused by a combination of factors as immaturity of the hypothalamo-pituitary-thyroid system, loss of the maternal thyroxine (T4) contribution, immaturity of thyroid hormone metabolism, and neonatal illness. Thyroid hormone is important in maturation of the brain, but also of heart and lungs. Low neonatal T4 concentrations in plasma are related to worse clinical and neurodevelopmental outcome. Despite these relationships, only few randomized clinical trials have been performed to find out whether T4 supplementation can improve clinical and/or neurodevelomental outcome of preterm infants. The currently available evidence does not support use of supplemental T4 in all preterm infants. There are, however, indications that T4 might improve neurodevelopmental outcome in infants born before 27 to 29 weeks of gestation. Therefore, it is necessary that new trials are set up to further study the benefits of thyroid hormones given in the neonatal period of very preterm infants.

Efficacy of automated auditory brainstem response hearing screening in very preterm newborns

OBJECTIVE

To investigate the efficacy of an automated auditory brainstem response (AABR) hearing screening method in very preterm newborns in the neonatal intensive care setting.

STUDY DESIGN

In this prospective cohort study, 90 consecutive preterm newborns (<32 weeks' gestational age) had AABR hearing screening weekly from birth until a bilateral pass result was obtained. If the newborn had a unilateral pass result, AABR screening was repeated in the same week. Data were analyzed by using the Kaplan-Meier survival function technique, resulting in a cumulative pass rate curve for postmenstrual age. Cox's regression method was used to analyze the effect of co-variables, such as sex and growth restriction, on pass rates.

RESULTS

Median gestational age was 29.5 weeks (range, 25.3-31.9 weeks), and median birth weight was 1115 g (range, 600-1960 g). Mean age was 6.2 days (SD 4.3) at first test, 15.7 (SD 8.1) at second test, and 21.4 (SD 8.6) at third test. Eighty percent (CI: 70.2%-89.8%) of the newborns passed at 30.3 weeks' postmenstrual age, 90% (CI: 83.6%-96.4%) passed at 31.2 weeks, and 100% passed at 34 weeks' postmenstrual age. The attainment of these pass rates correlated to postmenstrual age was not significantly influenced by sex, growth restriction, or gestational age at birth. Postnatal pass rates (in days) were strongly influenced by gestational age.

CONCLUSION

AABR pass rates of >80% can be obtained from 30 weeks' postmenstrual age. Therefore AABR neonatal hearing screening can be used before discharge from a neonatal intensive care unit.

Neonatal thyroxine supplementation in very preterm children: developmental outcome evaluated at early school age

OBJECTIVE

Transient hypothyroxinemia in very premature infants is associated with developmental problems. A randomized, placebo-controlled trial of thyroxine (T(4)) supplementation was conducted in a group of 200 infants <30 weeks' gestation. T(4) supplementation improved mental outcome at 2 years old in children of 25/26 weeks' gestation only. The effect of T(4) supplementation beyond 2 years of age is unknown. We present the effects of neonatal T(4) supplementation on outcome at early school age.

METHODS

Standardized measurements were used to assess cognitive, behavioral, and motor outcome, as well as a qualitative assessment of neurologic functioning. Survivors of the T(4) trial were assessed at the age of 5.7 years.

RESULTS

Ninety-nine percent of the 157 survivors participated. Outcome on all domains was comparable between the T(4) group and placebo group. In children <27 weeks' gestation, a 10 IQ point difference was found in favor of the T(4) group, whereas in children of 29 weeks' gestation, a difference of 15 IQ points was found in favor of the placebo group. Teachers' reports showed less behavioral problems in the T(4)-treated children of 25/26 weeks' gestation, but more behavioral problems in the T(4)-treated children of 27 weeks' gestation. Differences in motor outcome and neurologic outcome were in favor of the T(4)-treated children <29 weeks' gestation, but not of the T(4)-treated children of 29 weeks' gestation.

CONCLUSIONS

We found benefits of T(4) supplementation for children <29 weeks' gestation, and especially in children of 25/26 weeks' gestation. However, in children of 29 weeks' gestation T(4) supplementation is associated with more developmental problems.

Changes in plasma thyroid hormone levels after a single dose of triiodothyronine in premature infants of less than 30 weeks gestational age

OBJECTIVE

Evaluation of thyroid hormone response to a single administration of triiodothyronine (T3) early postnatally to premature infants of <30 weeks gestational age.

DESIGN

A prospective clinical trial with historical control.

METHODS

Ten infants born <28 weeks gestational age and ten infants born between 28 and 30 weeks gestational age were given 0.5 microg/kg T3 intravenously at 12 h after birth. The infants <28 weeks gestational age were also treated with thyroxine (T4; 8 microg/kg, once daily) during the first 6 weeks of life. Premature infants from a previous trial served as a matched historical control group. Analysis of variance for repeated measurements was performed.

RESULTS

For the infants <28-30 weeks gestational age mean plasma T3 concentrations were significantly higher in the T3-treated group (P=0.027) for at least 2 weeks, whereas mean plasma levels of T4, free T4 and TSH were comparable. For the infants <28 weeks gestational age plasma T3 levels were also significantly different after correction for gestational age (P=0.0002), with either comparable or higher values in the T3-treated infants up to 56 days after injection of T3. Mean plasma free T4 levels were lower during the first 3 days and higher or comparable thereafter (P=0.0014), and TSH suppression was more evident in the T3-treated infants (P=0.003).

CONCLUSION

A single administration of T3 to premature infants <30 weeks gestational age early postnatally results in a sustained increase of plasma T3 levels during the first weeks of life. In infants of 28-30 weeks gestational age this occurs without change in plasma free T4 levels, whereas in infants <28 weeks gestational age a transient decrease of plasma free T4 was present. The increase in plasma T3 is possibly caused by a T3-induced increase of type I deiodinase activity.

Evaluation of a new system of lens parameter selection and comparison of traditional vs one-step lens care systems for aspheric high-Dk RGP contact lenses

PURPOSE

We investigated the value of newly developed systems for parameter selection on the performance of high Dk rigid gas permeable (RGP) contact lenses with a spheric-aspheric design made of Boston Equa material in normal daily wear conditions. A comparison was also made between the safety and efficacy of a traditional care system vs a one-step chemical care system during the follow-up period of 1 year.

METHODS

A total of 66 patients were randomly assigned to traditional and newly developed systems for computing the back optical zone radius (BOZR) and the total diameter (TD) of the lenses. Evaluation parameters incorporated assessment of fit, visual acuity, wearing time, comfort, and lens condition.

RESULTS

The traditional method of computing the BOZR, using a method based on flat-K, predicted the BOZR successfully in 83% of the cases. Corneal topometry reached a lower, but not significantly different (P > 0.01) value of 75% correct prediction of BOZR. Analysis of the differences in eccentricity (E) values between quadrants per eye was a significant (P < 0.001) factor in fault predictions in the topometric system. A newly developed guide forTD selection performed, with 90% correct predictions, significantly (P < 0.01) better than a traditional method (72%) based on corneal diameter on supraversion. No significant differences (P > 0.05) were found in the capabilities of care systems (a traditional care system using a surfactant cleaner vs a one-step solution) to keep the lenses in proper condition and without deformation, over the 1 year follow-up period. The final success rate was 85%.

CONCLUSIONS

Although high Dk RGP contact lenses can be fit and used with a 85% success rate using advanced systems for determining the BOZR and TD, it remains necessary to evaluate the fit before dispensing high Dk RGP lenses in 15% of the cases. The one-step solution used in this study was a good starting point for lens care. If needed, surfactant cleaning in the traditional care system can be done without the risk of lens deformation.

Neurologic development of the newborn and young child in relation to maternal thyroid function

A prospective observational study was performed in pregnant women with known thyroid disease. We studied the effect of maternal thyroid function in the first half of pregnancy on the neurologic development of the infant in the first 2 y of life. Clinical and thyroid function data were collected from 20 pregnant women with known thyroid disease and their newborn children. Infants were divided into three groups according to their maternal thyroid function within the first half of pregnancy: Group A (n = 7): maternal subclinical hypothyroidism, Group B (n = 6): maternal euthyroidism, and Group C (n = 7): maternal hyperthyroidism or subclinical hyperthyroidism. Neurophysiologic, i.e. motor nerve conduction velocity and somatosensory evoked potentials and neurologic and developmental (Bayley scales) assessments were done. One infant, born to a mother with Graves' disease, developed transient hyperthyroidism. At the age of 6 and 12 mo, the mean mental developmental index (MDI) score was 16 points lower for infants in Group A than for those in Group B (p = 0.03 and 0.02, respectively). At the age of 24 mo, the mean MDI score was 6 points lower, which was not statistically significant. Neurophysiologic and neurologic assessments and the mean Psychomotor Developmental scores did not differ among the three groups. In conclusion, maternal subclinical hypothyroidism in the first half of pregnancy was associated with a lower mean MDI score in their infants during the first year of life.

Somatosensory evoked potentials in very preterm infants

OBJECTIVE

Cross-sectional and longitudinal reference values of cortical N(1) peak latency of the median nerve SEP in very preterm infants.

METHODS

In infants in a placebo control group within an L-thyroxine supplementation trial, born at less than 30 weeks' gestation, cortical N(1) peak latency was measured at 2 weeks, at term and at 6 months corrected age. Cross-sectional N(1) latency values obtained in 50 infants and complete series of longitudinal values obtained in 15 infants were analyzed in relation to postmenstrual age (PMA).

RESULTS

Mean N(1) latency decreased from 66 ms at 2 weeks to 38 ms at term and 20 ms at 6 months corrected age. Possible confounding factors did not have any significant effect on N(1) latency at 2 weeks or at term age except cranial ultrasound abnormalities at 2 weeks of age.

CONCLUSIONS

Longitudinal N(1) latency values were consistent with cross-sectional N(1) latency values. The observed N(1) latency at term and at 6 months corrected age suggest that extrauterine maturation of the somatosensory pathway in infants born at less than 30 weeks' gestation is delayed by extrauterine life.

Neonatal effects of nifedipine and ritodrine for preterm labor

OBJECTIVE

We compared nifedipine and ritodrine for treatment of preterm labor with respect to neonatal outcome.

METHODS

We conducted an open randomized multicenter study of neonatal outcome in 185 women who received either oral nifedipine (n = 95) or intravenous (IV) ritodrine (n = 90) for treatment of preterm labor. Secondary outcome measures included neonatal mortality and morbidity, especially neonatal intensive care unit (NICU) admission, respiratory distress syndrome (RDS), and intracranial bleeding.

RESULTS

There were no significant differences in umbilical artery pH values and Apgar scores between groups. Nifedipine was associated with lower admission rates to the NICU (49% versus 66%; odds ratio 0. 51, confidence interval 0.28, 0.93) compared with ritodrine, and lower incidences of RDS (21% versus 37%; 0.46, 0.24, 0.89), intracranial bleeding (18% versus 31%; 0.48, 0.24, 0.96), and neonatal jaundice (52% versus 67%; 0.53, 0.29, 0.97). Logistic regression analysis showed that even after correction for gestational age at birth, newborn risk of RDS, intracranial bleeding, or neonatal jaundice was significantly lower in the nifedipine group than the ritodrine group.

CONCLUSION

Nifedipine for treatment of preterm labor was associated with a lower incidence of neonatal morbidity than ritodrine. That difference appeared to be partly because of the higher tocolytic efficacy of nifedipine and partly because of an intrinsic beneficial effect of nifedipine, or the lack of harmful effects when compared with ritodrine.

Motor nerve conduction velocity in very preterm infants

Sufficient reference values for motor nerve conduction velocity (MNCV) in very preterm infants are not yet available. In the placebo infants within an L-thyroxine supplementation trial, born at less than 30 weeks' gestation, ulnar and posterior tibial MNCV measurements were performed shortly after birth. Repeated measurements were done at 2 weeks, at term, and at 6 months corrected age. Cross-sectional MNCV values obtained in 50 infants and longitudinal MNCV values obtained in 15 infants were analyzed in relation to postmenstrual age (PMA). Mean ulnar MNCV increased from 13 to 44 m/s and mean tibial MNCV from 11 to 37 m/s. Motor nerve conduction velocity was clearly related to PMA. Longitudinal MNCV values were consistent with cross-sectional MNCV values. Possible confounding factors did not have any significant effect on MNCV. In the ulnar nerve, extrauterine maturation during the first 2 weeks of life was delayed compared with intrauterine maturation.

Evaluation of the effect of thyroxine supplementation on behavioural outcome in very preterm infants

Two-hundred infants of <30 weeks gestational age were included in a randomized double-blind controlled trial to study the effect of thyroxine administration on neurodevelopmental outcome in very preterm children. The infants were given either a fixed dose of thyroxine (8 microg/kg birthweight/day) or placebo for the first 6 weeks of life. This paper evaluates the effect of thyroxine administration on behavioural outcome at the age of 2 years. More externalizing, especially destructive, behaviours were found in the group given thyroxine than in the placebo group. This difference was more pronounced in boys and in children born after 27 weeks' gestation. The thyroxine-treated children with behavioural problems had lower plasma-free thyroxine levels than the thyroxine-treated children without behavioural problems. This finding suggests that the presence of more behavioural problems in the group given thyroxine was not an immediate consequence of the treatment.

In vivo human corneal hydration control dynamics: a new model

PURPOSE

To introduce a new model describing human in vivo corneal deswelling after hypoxic contact lens wear, based on a damped harmonic oscillator, which can describe an overshoot in corneal deswelling, to compare this new model with the currently used exponential model, and also to test whether a diurnal variation in baseline corneal thickness exists that would have to be taken into consideration when calculating corneal deswelling curves.

METHODS

In nine healthy young adults, corneal thickness was measured every 30 minutes for 11.5 hours on average using modified optical pachometry (natural test). On another day, corneal deswelling was monitored for 11.1 hours on average after 2 hours of hypoxic contact lens wear (stress test). The damped harmonic oscillator model and the exponential model were used to calculate best-fitting deswelling curves. Natural test data were analyzed for the presence of a trend. Goodness of fit of the curves to the experimental data was analyzed using the F test.

RESULTS

In 82% of the deswelling curves the new damped harmonic oscillator model provided a better fit to the data than the exponential model (P < 0.05). An average overshoot in corneal thickness recovery of 5 microm (range, 0-11 microm) was found. In 50% of the natural tests significant trends were found, without any consistent similarities. The overshoot could not be explained by these trends.

CONCLUSIONS

The new damped harmonic oscillator model describes corneal deswelling after hypoxic contact lens wear more accurately than the exponential model. No consistent diurnal variation could be demonstrated.

Thyroid function in very preterm newborns: possible implications

Thyroid hormones are essential for brain maturation. Very preterm infants, who are at risk of neurodevelopmental disabilities also have low thyroxine (T4) and free thyroxine (FT4) values in the first weeks after birth. This transient hypothyroxinemia may in part be causal to the neurodevelopmental problems. We have carried out a randomized, double-blind, placebo-controlled trial with T4 in 200 infants less than 30 weeks gestation. T4 (or placebo) was given in fixed dose of 8 microg/kg birth weight per day during the first 6 weeks after birth. It resulted in a significant increase of T4, FT4, and reverse triiodothyronine (rT3). Thyrotropin (TSH) secretion was suppressed, and, probably as a result of TSH suppression, triodothyronine (T3) levels were decreased in the T4 group. Mortality was 14% in the T4 group and 21% in the placebo group (NS). No effect was found on morbidity. Heart rate was significantly higher in T4-treated infants less than 28 weeks gestation, but not in T4-treated infants 28 weeks or more, who had the highest FT4 levels. In the study groups as a whole, no clear effect of T4 administration was found on neurodevelopmental outcome. However, there was a strong trend toward improvement of adverse outcome, defined as death or abnormal developmental outcome at 2 years of age. In addition, mental outcome in a subgroup of T4-treated infants less than 27 weeks' gestation was significantly better than in placebo infants of the same age group. In conclusion, this trial does not clearly have conclusive results. New trials of thyroid hormone treatment should be carried out in preterm infants, in order to investigate whether indeed T4 supplementation is required in preterm infants less than 27 or 28 weeks gestation. Addition of T3 to the treatment schedule needs to be considered.

Thyroxine administration to infants of less than 30 weeks gestational age decreases plasma tri-iodothyronine concentrations

OBJECTIVE

To investigate the effect on thyroid hormone metabolism of the administration of thyroxine to very preterm infants.

DESIGN AND METHODS

Two hundred infants of less than 30 weeks gestation were enrolled into a randomized, double-blind, placebo-controlled trial. Thyroxine (T4) (at a fixed daily dose of 8 microg/kg birthweight) or placebo was started 12-24h after birth and discontinued 6 weeks later. Plasma concentrations of T4, tri-iodothyronine (T3), reverse T3 (rT3), TSH, and thyroxine-binding globulin were measured weekly during trial medication and 2 weeks thereafter.

RESULTS

The T4 and the placebo group each comprised 100 infants. Antenatal, perinatal, and postnatal clinical characteristics were comparable in both groups. T4 and rT3 were significantly increased in the T4 group. TSH concentrations were depressed in the T4 group and T3 was significantly decreased, probably as a result of TSH depression. The T4/T3 and T4/rT3 ratios differed significantly between the two study groups.

CONCLUSIONS

Daily T4 administration during the first 6 weeks after birth to infants of less than 30 weeks gestation prevents hypothyroxinemia, but decreases plasma T3 concentrations. Our finding possibly implies that very preterm infants should receive supplements of both T4 and T3.

Neurodevelopmental outcome at three years of age after fetal 'brain-sparing'

Intrauterine growth restriction (IUGR), occurring preterm, may be related to impaired neurodevelopmental outcome. We measured neurodevelopmental outcome (Hempel examination) at the age of three years in a cohort of infants born between 26 and 33 weeks in 1989. Fetuses were studied haemodynamically, using Doppler ultrasound. The ratio between the umbilical and the cerebral artery Pulsatility Index (U/C ratio) was calculated. This is a measure of redistribution of fetal blood preferentially to the brain and this may be a marker of fetal adaptation to placental insufficiency. Impaired fetal growth was also measured by the fetal growth ratio. Neonatal cranial ultrasound was performed to document intracranial haemorrhages and/or ischaemia. From the original cohort of 106 infants, 96 (91%) infants were examined at three years. After adjustment for obstetric variables, adverse Hempel outcome was related to neonatal cranial ultrasound abnormality and low head circumference at three years. Neither the U/C ratio nor fetal growth were independently associated with Hempel outcome. Fetal 'brain-sparing' in IUGR appears to be a benign adaptive mechanism preventing severe brain damage.

Somatosensory evoked potentials in very preterm infants in relation to L-thyroxine supplementation

OBJECTIVE

To study the effect of L-thyroxine supplementation on neurologic maturation in very preterm infants with transient hypothyroxinemia.

DESIGN

Randomized, double-blind, placebo-controlled, L-thyroxine supplementation trial.

SETTING

Level III neonatal intensive care unit.

SUBJECTS

A total of 200 infants <30 weeks' gestational age.

INTERVENTION

Subjects were randomly assigned to receive L-thyroxine (8 microg/kg birth weight per day) or a placebo during the first 6 weeks of life.

METHODS

Median nerve somatosensory evoked potentials were recorded, measuring cortical N1 peak latency at 2 weeks of age, at term, and at 6 months (corrected) age.

RESULTS

Cortical N1 peak latency was not decreased significantly in the L-thyroxine group compared with the placebo group throughout the study period.

CONCLUSION

L-Thyroxine supplementation during the first 6 weeks of life did not decrease cortical N1 peak latency in infants of <30 weeks' gestational age.

Outcome of very preterm small for gestational age infants: the first nine years of life

OBJECTIVE

To determine the influence of intrauterine growth retardation of preterm infants on mortality and cognitive development.

DESIGN

A nationwide study cohort of very preterm and/or small for gestational age infants (< 32 weeks and/or < 1500 g) born alive in 1983 in the Netherlands. Assessment on neuromotor and cognitive development at five years, and a parental questionnaire on school performance at nine years. Cognitive outcome is defined as handicap for mental and speech-language development, and need for special education.

SAMPLE

134 small for gestational age infants (< 10th centile) and 410 appropriate for gestational age infants (between 25th and 75th centile) of all infants between 25 and 32 weeks of gestational age were identified; infants with congenital malformations and not of caucasian race were excluded.

MAIN OUTCOME MEASURES

Neonatal mortality, in-hospital and five years mortality; Cognitive outcome at five years; School performance at nine years.

RESULTS

The mortality risk for small for gestational age compared with appropriate for gestational age infants was significantly higher, after adjustment for gestational age, sex, multiple pregnancy and mode of delivery (OR 2.56, 95% CI 1.26-5.26). Small for gestational age infants showed more often gross motor and minor neurological dysfunction, but less cerebral palsy than appropriate for gestational age infants. Cognitive outcome at five years in small for gestational age infants was significantly worse than appropriate for gestational age infants stratified for mode of delivery OR 2.44 (95% CI 1.05-5.55). At nine years of age significantly more small for gestational age infants (16.4%) needed special education than appropriate for gestational age infants (11.9%).

CONCLUSION

Intrauterine growth retardation increases the risk of mortality and of cognitive disorders.

Thyroid function in preterm newborns; is T4 treatment required in infants < 27 weeks' gestational age?

Thyroid hormones are essential for brain maturation. Very preterm infants, who are at risk of neurodevelopmental disabilities also have low T4 and FT4 values in the first weeks after birth. This transient hypothyroxinemia may in part be causal to the neurodevelopmental problems. We have carried out a randomised, double-blind, placebo-controlled trial with T4 in 200 infants < 30 weeks' gestation. In the study groups as a whole (n = 100 in the T4 group, n = 100 in the Placebo group), no clear effect of T4 administration was found. In this study we examined whether gestational age influenced the effect of T4 administration. The T4- and placebo groups were subdivided into 4 groups according to gestational age. FT4-values during the first weeks after birth were lowest in the youngest gestational age group in the T4 as well as in the placebo group. In this group with infants < 27 weeks' gestation mental developmental outcome at 2 years of age was significantly better than in the placebo group of the same gestational age. There was also a trend towards a better psychomotor and neurological outcome. Beyond 27 weeks' gestation, no clear effect of T4 could be found; on the contrary, a possible harmful effect on mental developmental outcome might be the result. In conclusion. T4 treatment possibly improves developmental outcome in infants < 27 weeks' gestation, but seems not necessary beyond this gestational age.

Motor nerve conduction velocity in very preterm infants in relation to L-thyroxine supplementation

BACKGROUND

Transient hypothyroxinemia is common in preterm infants and has been associated with neurodevelopmental dysfunction and slow nerve conduction velocity. It is still unknown whether L-thyroxine supplementation is required. During an L-thyroxine supplementation trial, motor nerve conduction velocity was measured to answer the question whether L-thyroxine supplementation improves motor nerve conduction velocity.

METHODS

Two hundred infants < 30 weeks' gestational age were enrolled in a randomized, double-blind, placebo-controlled L-thyroxine supplementation trial. L-Thyroxine (8 micrograms/kg birthweight per day) or a placebo was administered during the first 6 weeks of life. Motor nerve conduction velocity was measured in the ulnar and posterior tibial nerve shortly after birth, at 2 weeks, at 40 weeks, and at 66 weeks postmenstrual age.

RESULTS

At 2 weeks, the ulnar motor nerve conduction velocity had improved in the L-thyroxine group compared with the placebo group, although the difference was not statistically significant (difference between means: 0.8 msec; 95% CI: -0.13 to 1.80; p = 0.06). Later on, no effect of L-thyroxine supplementation on motor nerve conduction velocity was found.

CONCLUSION

This study shows that in infants < 30 weeks' gestational age L-thyroxine supplementation during the first 6 weeks of life does not clearly improve motor nerve conduction velocity.

Thyroid function in very preterm infants: influences of gestational age and disease

It is not known how immaturity and disease influence postnatal thyroid function in infants <30 wk of gestational age. We performed serial measurements of plasma thyroxine (T4), free T4 (FT4), triiodothyronine (T3), reverse T3 (rT3), TSH, and T4-binding globulin (TBG) in 100 infants of <30 wk of gestation, during the first 8 postnatal weeks, to investigate the influences of disease and gestational age on the time course of thyroid hormones. One hundred infants were divided twice into two groups: 1) in a group of 25-28 and of 28-30 wk of gestation; and 2) in a sick and a healthy group, with similar gestational ages. The time course of T4, FT4, T3, TSH, and TBG, but not rT3 differed significantly (p < 0.005) between the gestational age groups. T4 and FT4 decreased to levels below the cord blood value with a deeper FT4 nadir on d 7 in the youngest group. Disease decreased T4, FT4, T3, TSH, and TBG concentrations especially during the 1st wk after birth (p < 0.005). However, the FT4 nadir on d 7 was similar in sick and healthy infants. After 3 wk, T4, FT4, T3, and TBG were higher in the sick group compared with the healthy group. rT3 levels were not increased in sick infants. We conclude that the extent of the FT4 decrease after birth in infants of <30 wk gestation is mainly influenced by gestational age and probably reflects a transient depletion of thyroidal hormone reserves. rT3 cannot be used as a marker of nonthyroidal illness in very preterm infants.

Effects of thyroxine supplementation on neurologic development in infants born at less than 30 weeks' gestation

BACKGROUND

Premature infants who have transient hypothyroxinemia in the first weeks of life may have developmental delay and neurologic dysfunction. Whether thyroxine treatment during this period results in improved developmental outcomes is not known.

METHODS

We carried out a randomized, placebo-controlled, double-blind trial of thyroxine supplementation in 200 infants born at less than 30 weeks' gestation. Thyroxine (8 microg per kilogram of birth weight) or placebo was administered daily, starting 12 to 24 hours after birth, for six weeks. Plasma free thyroxine concentrations were measured weekly for the first eight weeks after birth. Scores on the Bayley Mental and Psychomotor Development Indexes and neurologic function were assessed at 6, 12, and 24 months of age (corrected for prematurity).

RESULTS

Mortality and morbidity up to the time of discharge from the hospital were similar in the study groups. At 24 months of age, 157 infants were evaluated. Overall, neither mental nor psychomotor scores differed significantly between the study groups at any time, nor was the frequency of abnormal neurologic outcome significantly different. In thyroxine-treated infants born at gestational ages of less than 27 weeks, the score on the Bayley Mental Development Index at 24 months of age was 18 points higher than the score for the infants with similar gestational ages at birth in the placebo group (P=0.01); for thyroxine-treated infants born at 27 weeks or later, the mental-development score was 10 points lower than that of their counterparts in the placebo group (P=0.03). There was no relation between the initial plasma free thyroxine concentration and the effect of treatment.

CONCLUSIONS

In infants born before 30 weeks' gestation, thyroxine supplementation does not improve the developmental outcome at 24 months.

Fetal brain sparing is associated with accelerated shortening of visual evoked potential latencies during early infancy

OBJECTIVE

Our purpose was to assess the effects that fetal growth restriction exerts on the myelination of the developing brain.

STUDY DESIGN

Fetal haemodynamic centralization, an adaptive strategy to growth restriction caused by placental insufficiency, was determined by Doppler ultrasonography. Infants with a raised ratio between umbilical artery pulsatility index and cerebral artery pulsatility index are severely growth restricted. Visual evoked potentials give information on the degree of brain myelination. Shortening of visual evoked potential latencies is a normal feature of myelination. In a consecutive series of 105 Neonates, visual evoked potentials were recorded at the corrected ages of 6 months and 1 years. Correction for possible confounders, such as cranial ultrasonographic findings, gestational age, and head circumference, was performed.

RESULTS

At 6 months, infants with a raised umbilical artery/cerebral artery pulsatility index ratio have shorter visual evoked potential latencies. Opposite of neonates with a normal umbilical artery/cerebral artery ratio, they show no postnatal maturational shortening of visual evoked potential latencies.

CONCLUSION

Accelerated neurophysiologic maturation, found in infants with a high umbilical artery/cerebral artery ratio, might be the result of a beneficial adaptive process to severe fetal growth restriction.

Type II and type III deiodinase activity in human placenta as a function of gestational age

Thyroid hormones are essential for fetal development. T4 can be activated by type I (ID-I) and type II (ID-II) iodothyronine deiodinase or inactivated by type III deiodinase (ID-III). The influence of placental ID-II and ID-III on the regulation of fetal thyroid hormone levels was investigated. Using [125I]T4 and [125I]T3, respectively, ID-II and ID-III activities were measured in homogenates of normal human placentas from 6-43 weeks gestational age and in placentas from five term neonates with a total thyroid hormone synthesis defect. ID-II and ID-III activities related to protein or DNA concentration decreased and total placental ID-III activity increased significantly during pregnancy, whereas the increase in total placental ID-II activity was not significant. Absolute placental ID-II activity was approximately 200 times lower than ID-III activity at all gestational ages. Therefore, fluctuations in ID-II activity were not likely to have a significant influence on fetal thyroid hormone concentrations, but may play a role in the regulation of intraplacental T3 generation. The high ID-III activity most likely influences the thyroid hormone economy of the fetus. Severely hypothyroid newborns showed strongly decreased serum T4 levels, but serum T3 and placental ID-III activities were similar to those in euthyroid newborns. These results suggest that placental ID-III activity is regulated by serum T3, but not by serum T4.

[Poor prognosis in children with ultrasonographically diagnosed abnormalities of the central nervous system]

OBJECTIVE

Long-term follow-up of children with a prenatally diagnosed malformation of the central nervous system.

DESIGN

Descriptive study.

SETTING

Department of prenatal diagnosis, Academic Medical Center, Amsterdam, the Netherlands.

METHODS

Evaluation of all documented ultrasound examinations between 1985 and 1990 (6 years). These ultrasound examinations were performed in women with an increased risk for a foetal malformation, because of obstetrical complications or when a foetal malformation was suspected on ultrasound examination performed elsewhere. Paediatricians and general practitioners were asked to provide follow-up data on the children who were still alive.

RESULTS

Seven out of 67 foetuses with a prenatally diagnosed malformation of the central nervous system lived longer than one month. Two out of these 7 children developed normally, one child died after several years and four children were severely retarded. The two children who developed normally both had mild hydrocephaly.

CONCLUSION

Prognosis of children with a prenatally diagnosed malformation of the central nervous system is poor. Children with mild hydrocephaly may have a better prognosis.

The relation between neonatal thyroxine levels and neurodevelopmental outcome at age 5 and 9 years in a national cohort of very preterm and/or very low birth weight infants

Transient neonatal hypothyroxinemia is very common in preterm infants. The literature on the effect of this hypothyroxinemia is, however, controversial, and large or long-term follow-up studies are not available. In a nationwide prospective follow-up study on very preterm and (or) very low birth weight infants (n = 717), we studied the relationship between thyroxine levels in the 1st wk of life and neurodevelopmental outcome at 5 y of age and school performance at 9 y of age. Thyroxine concentrations from filter paper eluates were determined in 717 infants: 32% had levels of more than 3 SD below the mean (< 60 nmol/L). The percentage of infants with such low levels increased with decreasing gestational age. At the age of 5 y, 96% of survivors (n = 640) were available for extensive neurodevelopmental examination: 85 (13.3%) had a disability and 92 (14.3%) a handicap. At the age of 9 y, 83% of survivors (n = 552) answered a questionnaire on school performance: 300 (54.3%) were in mainstream education in a grade appropriate for age, 151 (27%) were in mainstream education with grade retention, and 101 (18.3%) were in special education. Both neurologic dysfunction at age 5 y and school failure at age 9 y were significantly related to lower neonatal thyroxine levels even after adjustment for other perinatal factors (odds ratio, 1.3). Whether this relationship is causal should be investigated. If a causal relationship exists, substitution therapy may at least partially prevent neurologic dysfunction and learning disabilities, both common sequelae of very preterm birth.

Neonatal cerebral circulation in relation to neurosonography and neurological outcome: a pulsed Doppler study

In the pathogenesis of neonatal intracranial pathology and adverse neurologic outcome, severe instability of the neonatal cerebral circulation might play an important role. To examine this hypothesis the relationship was explored between intracranial pathology as detected by neurosonography during the first week of life, changes in cerebral blood flow velocity (CBFV) as measured by Doppler ultrasound in the same period and neurologic outcome, as measured by standardized tests during the first year of life. A group of 128 infants born after a pregnancy duration between 25 2/7 and 32 6/7 weeks was studied. In 40% of the infants, the time of occurrence of both types of intracranial pathology was within 1 hour after birth. No relation could be demonstrated between this occurrence and CBFV. Also after the appearance of intracranial pathology no specific changes in CBFV were seen. CBFV was associated with neurological outcome at term age. However, CBFV did not predict outcome of neurological examination at 6 and 12 months of corrected age. Intracranial hemorrhages were associated with abnormal neurological outcome at all assessments. Ischemic lesions were only associated with adverse outcome at 12 months of age.

Effect of fetal brainsparing on the early neonatal cerebral circulation

The effect of antenatal brainsparing on subsequent neonatal cerebral blood flow velocity (CBFV) was studied in very preterm infants. CBFV was determined, using a pulsed Doppler technique, both in the fetal and neonatal period. Neonatally, blood pressure and transcutaneous carbon dioxide tension (TcPCO2) was monitored simultaneously; daily cranial ultrasound examinations were performed. In infants with evidence of brainsparing a higher mean value of CBFV and a different pattern of changes of CBFV during the first week of life was demonstrated compared with infants with normal fetal cerebral haemodynamics. No differences were found in blood pressure and TcPCO2. The incidence of intracranial haemorrhages and of ischaemic echo-dense lesions was also the same for both groups. In a multivariate statistical model gestational age, antepartum brainsparing, and TcPCO2 all contributed significantly in explanation of variation in CBFV. It is speculated that a different setting of cerebral autoregulation related to differences in gestational age or to brainsparing might explain the difference in changes found in neonatal CBFV.

Dermatography as a modern treatment for coloring leucoma corneae

Since antiquity many attempts were made and hence many methods were devised to minimize the disfiguration and stigmatization caused by leucoma corneae. Dermatography, a refined, modified tattooing technique, was used successfully in three cases of leucoma corneae. The materials and method are safe and simple. Over a 3-year follow-up period, no negative reactions were found. The cosmetic results were very satisfactory.

Corneal eccentricity as a tool for the diagnosis of keratoconus

Ninety-nine eyes with keratoconus of 64 patients were examined using the sagittal radii method to determine the corneal flattening and compared with 100 eyes of 50 healthy controls. To express the degree of this flattening, four numerical eccentricity (E) values for each eye were calculated. The highest E value of the four was chosen as a parameter for diagnosis of the disease. In keratoconus patients in whom the highest E values of keratoconus eyes were > or = 0.8, the specificity of the test was 98% and the sensitivity was 97%. This abnormal eccentricity was observed in keratoconus eyes with a visual acuity of 1.0, whereas slit-lamp examination showed no abnormalities. This study demonstrates that eccentricity can be helpful to diagnose keratoconus at an early stage.

Morphology and function of the corneal endothelium after long-term contact lens wear

PURPOSE

To examine whether corneal hydration control is impaired in corneas with endothelial morphologic changes (increased variation in cell size and cell angularity) due to long-term low gas-permeable contact lens wear.

METHODS

Twenty-one long-term wearers of low gas-permeable contact lenses (mean age, 41 years +/- 8 SD) and 18 age-matched controls (mean age, 42 years +/- 8 SD) were studied. To assess endothelial morphology, endothelial photographs were taken, enlarged 400X, scanned into a computer, and evaluated. Hydration control was assessed by a corneal stress test. Corneal swelling was induced by applying low gas-permeable soft contact lenses for 2 hours during eye closure. After the lenses were removed, the rate of deswelling was determined using optic pachometry.

RESULTS

Morphologic analysis of the endothelial photographs showed a significant increase of polymegethism (P < 0.01) and pleomorphism (P < 0.01) in the group wearing contact lenses compared with the control group. The percentage of recovery of corneal thickness per hour (PRPH) from induced swelling proved to be significantly lower (P = 0.03) and the induced swelling proved to be significantly lower (P < 0.01) in the group wearing contact lenses than in the control group. Multiple regression analysis showed that the PRPH decreased as the morphologic alterations increased. However, this trend appeared not to be significant at the 5% level. A significant relationship was found between morphologic parameters and induced swelling, indicating that induced swelling decreased as the morphologic alterations increased.

CONCLUSION

The results of this study indicate that increased endothelial polymegethism and pleomorphism may be accompanied by a decreased corneal hydration control in people who wear contact lenses.

The blue-green autofluorescence of the human ocular lens after the wear of PMMA contact lenses

The green ocular lens autofluorescence was determined in 30 Poly Methyl Meth Acrylate (PMMA) contact lens wearing volunteers and compared to that of 21 healthy non-contact lens wearing controls to determine whether a contact lens, reducing UV-A intensity reaching the eye, might protect the ocular lens against cataract formation. Increased autofluorescence was considered an indicator of increased probability for cataract formation. A multiple regression procedure revealed a significant yearly increase of autofluorescence with age (p < 0.01) which did not differ significantly (p > 0.86) from that in the controls. The regression procedure also revealed a decrease of the autofluorescence as a function of contact lens wear, but this decrease was not significant (p = 0.3). The order of magnitude of the decrease (-25%) corresponded to that of the calculated decrease in UV-A intensity at the ocular lens (-39%). This study could not support the thesis that cataract formation can be prevented by wearing PMMA contact lenses.

Good subjective presbyopic correction with newly designed aspheric multifocal contact lens

Many people of the so-called 'baby-boom' of 1945, nowadays require presbyopic correction. A lot of them choose for multifocal contact lenses, but this is not the perfect solution. Decreased visual acuity and contrast sensitivity, and appearance of haloes, 'ghosting' and glare are a problem. In this pilot study, with ten randomly, selected, consecutive patients, a newly designed soft aspheric multifocal contact lens was tested for visual performance and comfort on day 1 and after six months' wear. Success rate was 80% after six months. Visual acuity was good with exception for near vision under low illumination conditions. Two patients mentioned haloes. A statistical significant loss of contrast sensitivity was recorded on day 1 for the spatial frequencies 6.0, 12.0 and 18.0 cpd (cycles per degree) under high and low illumination. As well as for the spatial frequencies 12.0 and 18.0 cpd under high illumination and 6.0 cpd under low illumination (p = 0.05) after six months' wear. Mean overrefraction was limited. All patients recorded good comfort.