The making of fetal surgery

Fetal diagnosis prompts the question for fetal therapy in highly selected cases. Some conditions are suitable for in utero surgical intervention. This paper reviews historically important steps in the development of fetal surgery. The first invasive fetal intervention in 1963 was an intra-uterine blood transfusion. It took another 20 years to understand the pathophysiology of other candidate fetal conditions and to develop safe anaesthetic and surgical techniques before the team at the University of California at San Francisco performed its first urinary diversion through hysterotomy. This procedure would be abandoned as renal and pulmonary function could be just as effectively salvaged by ultrasound-guided insertion of a bladder shunt. Fetoscopy is another method for direct access to the feto-placental unit. It was historically used for fetal visualisation to guide biopsies or for vascular access but was also abandoned following the introduction of high-resolution ultrasound. Miniaturisation revived fetoscopy in the 1990 s, since when it has been successfully used to operate on the placenta and umbilical cord. Today, it is also used in fetuses with congenital diaphragmatic hernia (CDH), in whom lung growth is triggered by percutaneous tracheal occlusion. It can also be used to diagnose and treat urinary obstruction. Many fetal interventions remain investigational but for a number of conditions randomised trials have established the role of in utero surgery, making fetal surgery a clinical reality in a number of fetal therapy programmes. The safety of fetal surgery is such that even non-lethal conditions, such as myelomeningocoele repair, are at this moment considered a potential indication. This, as well as fetal intervention for CDH, is currently being investigated in randomised trials.

Perinatal and early surgical outcome for the fetus with hypoplastic left heart syndrome: a 5-year single institutional experience

OBJECTIVES

To review our experience with the prenatal diagnosis of hypoplastic left heart syndrome (HLHS). Our goal was to establish the benchmark for perinatal and early surgical outcome in the current era, from a center with an aggressive surgical approach and a cohort with a high level of intention-to-treat.

METHODS

Outcome was assessed in fetuses with HLHS following stratification into high-risk and standard-risk categories. High risk was defined as the presence of any of the following: extracardiac, genetic or chromosomal anomalies; prematurity of < 34 weeks' gestation; additional cardiac findings such as intact or highly restrictive atrial septum, severe degree of tricuspid regurgitation or severe ventricular dysfunction. Standard risk was defined as absence of these risk factors.

RESULTS

Of 240 fetuses evaluated over 5 years, 162 (67.5%) were in the standard-risk group and 78 (32.5%) were in the high-risk group. Of the 240 sets of parents, 38 (15.8%) chose termination or non-intervention at birth at initial prenatal counseling and 185 of the neonates (77.1%) underwent first-stage Norwood surgery with 155 surviving and 30 deaths, giving an overall Norwood operative survival of 83.8%. Breakdown by risk class reveals a significant Norwood operative survival advantage for the standard-risk group (92.8%) over the high-risk group (56.5%) (P < 0.001).

CONCLUSIONS

Following prenatal diagnosis of HLHS, families should be strongly encouraged to undertake comprehensive prenatal evaluation in order to obtain an accurate prognosis. One-third have additional risk factors that limit survival outcome, however two-thirds do not and have an excellent chance of early survival.

Reproductive outcomes in subsequent pregnancies after a pregnancy complicated by open maternal-fetal surgery (1996-2007)

OBJECTIVE

The reproductive and gynecologic outcomes for women after the pregnancy complicated by open maternal-fetal surgery (OMFS) were evaluated.

STUDY DESIGN

The retrospective review identified 93 women with OMFS from a single institution (1996-2007). Consent and questionnaires were sent to women. Institutional review board approval was obtained from the Committee for Protection of Human Subjects.

RESULTS

The total return rate was 57.3%. Total pregnancies reported were 47, with 36 delivering after 20 weeks' gestation. The uterine dehiscence and rupture rates were 14% and 14%, respectively. Fetal anomalies occurred in 4 subsequent pregnancies. Normal conception occurred in 98% of subsequent pregnancies. Gynecologic issues were reported by 8 women, with infertility, abdominal pain, and ovarian and uterine factors.

CONCLUSION

The reproductive outcomes of uterine dehiscence (14%) and rupture (14%) in a subsequent pregnancy continue to be a major counseling issue for OMFS. Fertility and gynecologic factors do not appear to be increased for women undergoing OMFS.

Predicting the severity of congenital high airway obstruction syndrome

BACKGROUND

Congenital high airway obstruction syndrome (CHAOS) is caused by complete or near-complete obstruction of the fetal airway. Obstruction sets in motion a sequence of events that can ultimately lead to fetal demise. However, on rare occasions in utero airway decompression occurs, reversing syndromic findings and improving the prognosis. In our relatively large series of CHAOS patients, we have observed a spectrum of clinical severity. The aim of this study was to identify the prenatal characteristics of CHAOS predictive of a milder postnatal course.

METHODS

The medical charts of all fetuses observed at our institution with the diagnosis of CHAOS were reviewed for radiologic findings, delivery information, perinatal course, autopsy or discharge report, and long-term follow-up.

RESULTS

Between 1996 and 2008, 12 fetuses with CHAOS were identified. Four fetuses had no evidence of hydrops on initial imaging. Of the 8 fetuses displaying hydrops, 3 were terminated, 2 died in utero, and 1 with multiple anomalies died at birth. Six fetuses were delivered via the ex utero intrapartum therapy procedure for attempted salvage, and 5 of the 6 survived the neonatal period including all 4 fetuses without hydrops. Serial prenatal imaging demonstrated less severe signs of CHAOS in 3 fetuses, and in 2 of them, direct laryngoscopy revealed a tiny opening in the airway. All 3 fetuses that showed improvement on serial imaging survived the neonatal period and were discharged home by 2-10 weeks of age.

CONCLUSIONS

Although the natural history of CHAOS is variable, trends in prenatal ultrasound findings are highly predictive of postnatal outcome and are a valuable guide to prenatal counseling.

Species number and endemism: the galapagos archipelago revisited

Regression analyses to determine plant species number are repeated for the Galápagos Islands with new data. The multiple curvilinear regression gives the best prediction of species number, with island area making the only significant contribution. The proportion of species endemic to the Galápagos is highest in the arid, transition zone and on small islands, and lowest in the littoral and mesic zones. This is explained in terms of zone-specific immigration and extinction rates and the very recent appearance of moist upland climates in the archipelago.

Outcomes in a cohort of patients with Stage I twin-to-twin transfusion syndrome

OBJECTIVE

To determine pregnancy outcomes of patients who present with Stage I twin-to-twin transfusion syndrome (TTTS).

METHODS

This was a retrospective review of all patients with TTTS referred to our institution between January 2005 and December 2006. Quintero criteria were used for staging. Laser ablation was not offered to patients with Stage I disease.

RESULTS

A total of 155 twin pregnancies were evaluated for TTTS during this period. Forty-two met the criteria for Stage I and were included in the analysis. The overall survival to discharge was 82%. The mean gestational age at the time of consultation was 20.9 +/- 0.4 weeks. A total of 23 cases (54.8%) underwent amnioreduction. Progression of TTTS requiring invasive therapy occurred in four cases. The mean gestational age at delivery was 32.5 +/- 0.62 weeks. When divided according to use of amnioreduction, there were no statistically significant differences between the groups for gestational age at delivery or for birth weight. Those Stage I cases with a CHOP cardiovascular score of 5 or higher delivered almost 3 weeks earlier than the remainder of the cohort.

CONCLUSIONS

Progression of TTTS beyond Stage I occurred in only 9.5% of the cohort. Mean gestational age at delivery and survival to discharge did not differ between Stage I patients and those treated with placental laser ablation for more advanced stages of TTTS.

The relationship of seizure activity and chronic epilepsy in early infancy and short-term neurodevelopmental outcome following fetal myelomeningocele closure

We explored the relationship between seizure activity (SA) and/or chronic epilepsy (CE) and short-term neurodevelopmental outcomes following fetal myelomeningocele (fMMC) surgery. Retrospective databases and a parental questionnaire focusing on common complications of hindbrain herniation associated with MMC were used to determine the incidence of seizures following fMMC surgery. The Bayley Scales of Infant Development II was used to evaluate the neurocognitive outcomes. The available 3-year outcome data were used for analysis. 54 children underwent fMMC closure at our institution between 1998 and 2003. 48 (89%) families participated. The shunt rate was 50% (n=24). Seizures developed in 8/48 (17%) children, 2 (8%) non-shunted and 6 (25%) shunted (P=0.07). Of those six, 3 developed CE. Neurodevelopmental scores in the average range were found in both non-shunted and 3 shunted fMMC children. The remaining 3 shunted toddlers had CE and significant neurodevelopmental delays. Of those, 2 had severe intracranial hemorrhage and one developed frequent apneic spells in combination with epilepsy. The incidence of seizures in fMMC children was similar to previously reported data of postnatally repaired MMC patients. SA alone without CE was not associated with a worse neurocognitive outcome. The occurrence of severe acquired intracranial injury and CE, however, appeared to be correlated with adverse neurocognitive outcome following fMMC surgery.

Fronts, jumps and secondary introductions suggested as different invasion patterns in marine species, with an increase in spread rates over time

Not all introduced (invasive) species in a region will spread from a single point of introduction. Long-distance dispersal or further introductions can obscure the pattern of spread, but the regional importance of such processes is difficult to gauge. These difficulties are further compounded when information on the multiple scale process of invasive species range expansion is reduced to one-dimensional estimates of spread (e.g. km yr(-1)). We therefore compared the results of two different metrics of range expansion: maximum linear rate of spread and accumulation of occupied grid squares (50 x 50 km) over time. An analysis of records for 54 species of introduced marine macrophytes in the Mediterranean and northeast Atlantic revealed cases where the invasion process was probably missed (e.g. Atlantic Bonnemaisonia hamifera) and suggested cases of secondary introductions or erratic jump dispersal (Dasysiphonia sp. and Womersleyella setacea). A majority of species analysed showed evidence for an accumulation of invaded sites without a clear invasion front. Estimates of spread rate are increasing for more recent introductions. The increase is greater than can be accounted for by temporally varying search effort and implies a historical increase in vector efficiency and/or a decreased resistance of native communities to invasion.

Prenatal diagnosis and postnatal outcome of fetal spinal defects without Arnold-Chiari II malformation

OBJECTIVE

To determine the prenatal evolution/natural history and postnatal outcome of fetuses diagnosed with a neural tube defect (NTD) lacking the Arnold-Chiari-II malformation (ACM II).

MATERIAL AND METHODS

This retrospective study reviewed 16 fetuses evaluated with ultrasound (US) and MRI at a single referral center from 1/2000 to 8/2007. Follow-up studies and available postnatal outcomes were reviewed.

RESULTS

Postpartum diagnosis was terminal myelocystoceles 7/16 (44%); myelomeningoceles (MMCs) 3/16 (19%); lipomyelomeningoceles 2/16(13%); and thoracic myelocystocele 1/16 (6%). Three patients (19%) were lost to follow-up or termination of pregnancy. Two prenatally diagnosed 'closed' NTD were postnatally found to be MMCs. Three of the myelocystoceles had additional omphalocele, bladder extrophy, imperforate anus and spinal defect (OEIS complex). For the total cohort, impaired lower extremity function was seen in 38%, impaired bladder function in 64%, and ventriculoperitoneal shunting in 8%. Four fetuses with a myelocystocele developed hindbrain herniation in the third trimester of pregnancy. The preterm delivery rate was 38%. Five of eight (63%) neonates with postnatally diagnosed myelocystoceles had mothers with a body mass index over 30.

CONCLUSION

Prenatal differentiation between closed and open NTD is not always possible. Postnatal outcome of isolated myelocystocele and MMC seems to be more favorable than for an NTD with ACM II (shunt requirement). Incontinence is the major childhood morbidity. Maternal obesity may be a risk factor for closed NTDs.

Fetal thoracic and bladder shunts

Congenital obstructive lesions involving the bladder and the lung can lead to serious complications for the newborn. The in-utero placement of a diverting shunt in the fetal bladder or thoracic cavity can decrease the morbidity and mortality associated with these obstructive conditions. This review focuses on the indications for prenatal evaluation, technique, and outcomes for those fetuses with a lower urinary tract obstruction, congenital pleural effusion or macrocystic congenital cystic adenomatoid malformation after placement of a vesicoamniotic or thoracoamniotic shunt.

Haploidentical in utero hematopoietic cell transplantation improves phenotype and can induce tolerance for postnatal same-donor transplants in the canine leukocyte adhesion deficiency model

In the murine model, in utero hematopoietic cell transplantation (IUHCT) has been shown to achieve low levels of allogeneic chimerism and associated donor-specific tolerance permitting minimal conditioning postnatal hematopoietic stem cell transplantation (HSCT). In this pilot study, we investigated IUHCT in the canine leukocyte adhesion deficiency (CLAD) model. Haploidentical IUHCT resulted in stable low-level donor cell chimerism in all dogs that could be analyzed by sensitive detection methodology (4 of 10) through 18 months of follow-up. In the 2 CLAD recipients, low-level chimerism resulted in amelioration and complete reversal of the CLAD phenotype, respectively. Six recipients of IUHCT (5 carriers and 1 CLAD) subsequently received postnatal HSCT from the same haploidentical prenatal donor after minimal conditioning with busulfan 10 mg/kg. Chimerism in 2 of 5 CLAD carriers that underwent HSCT increased from < 1% pre-HSCT to sustained levels of 35% to 45%. Control animals undergoing postnatal haploidentical HSCT without IUHCT had no detectable donor chimerism. These results demonstrate that haploidentical IUHCT in the CLAD model can result in low-level donor chimerism that can prevent the lethal phenotype in CLAD dogs, and can result in donor-specific tolerance that can facilitate postnatal minimal conditioning HSCT.

Like a rolling stone: the mobility of maerl (Corallinaceae) and the neutrality of the associated assemblages

Beds of nonattached coralline algae (maerl or rhodoliths) are widespread and considered relatively species rich. This habitat is generally found in areas where there is chronic physical disturbance such that maerl thalli are frequently moved. Little is known, however, about how natural disturbance regimes affect the species associated with maerl. This study compared the richness, animal abundance, and algal biomass of maerl-associated species over a two-year period in a wave-disturbed bed and a sheltered maerl bed. Changes in associated species over time were assessed for departures from a neutral model in which the dissimilarity between samples reflects random sampling from a common species pool. Algal biomass and species richness at the wave-exposed site and on stabilized maerl at the sheltered site were reduced at times of higher wind speeds. The changes in species richness were not distinguishable from a neutral model, implying that algal species were added at random to the assemblage as the level of disturbance lessened. Results for animal species were more mixed. Although mobile species were less abundant during windy periods at the exposed site, both neutral and non-neutral patterns were evident in the assemblages. Artificial stabilization of maerl had inconsistent effects on the richness of animals but always resulted in more attached algal species. While the results show that the response of a community to disturbance can be neutral, the domain of neutral changes in communities may be relatively small. Alongside non-neutral responses to natural disturbance, artificial stabilization always resulted in an assemblage that was more distinct than would be expected under random sampling from a common pool. Community responses to stabilization treatments did not consistently follow the predictions of the dynamic equilibrium model, the intermediate disturbance model, or a facilitation model. These inconsistencies may reflect site-specific variation in both the disturbance regime and the adjacent habitats that provide source populations for many of the species found associated with maerl.

In utero meconium passage in fetuses and newborns with myelomeningocele

OBJECT

The authors retrospectively investigated whether midgestational fetal myelomeningocele (fMMC) repair alters intrauterine meconium exposure.

METHODS

Prior to the National Institutes of Health Management of Myelomeningocele Study, 54 fetuses underwent fMMC repair at the authors' institution. Forty-six fMMC sacs were available for pathological examination and 53 MMC sacs from postnatally repaired MMCs (pMMCs) were available for comparison. The presence and distribution of meconium were blindly evaluated using a grading system defined as follows: absent (no meconium present), mild (<10 meconium-positive histiocytes [MPHs]/hpf), moderate (10-25 MPHs/hpf), and severe (>25 MPHs/hpf). Hall's bile stain was used to confirm meconium and Prussian blue and Fontana Masson stains to exclude hemosiderin and melanin, respectively.

RESULTS

Compared to pMMCs (79%), meconium histiocytosis was less prevalent in fMMC sacs (57%; p=0.017). Meconium staining was completely absent in 43% of the fMMC sacs. Mild meconium histiocytosis was found in 35% fMMC and 61% pMMC sacs (p=0.035). There was no statistical difference between groups with moderate and severe meconium histiocytosis.

CONCLUSIONS

Meconium passage in MMCs can occur early in fetal life. Fetal MMC repair may reduce the duration of meconium exposure, thereby potentially limiting the toxic injury to the vulnerable neural elements.

Lower extremity neuromotor function and short-term ambulatory potential following in utero myelomeningocele surgery

OBJECTIVE

To evaluate lower extremity neuromotor function (LENF) and short-term ambulatory potential following fetal myelomeningocele (fMMC) closure.

METHODS

Retrospective chart review of 54 children that underwent fMMC closure at our institution prior to the NIHCD-MOMS trial. Neonatal LENF was compared to predicted function based on spinal lesion level assigned by prenatal ultrasound. Ambulatory status was classified as independent walkers (walks without assistive appliances), assisted walker (requires walking aid), and non-ambulatory (wheelchair bound).

RESULTS

Thoracic, lumbar, and sacral level lesions were present in 4, 44 and 6 fMMC infants, respectively. 31/54 of fMMC children (57.4%; median: 2 levels, range: 1-5) had better than predicted, 13/54 (24.1%) same as predicted and 10/54 (18.5%; median: 1 level, range: 1-2) worse than predicted LENF at birth. At a median follow-up age of 66 months (36-113), 37/54 (69%) walk independently, 13/54 (24%) are assisted walkers, and 4/54 (7%) are wheelchair dependent. The strongest factors predicting a lower likelihood to walk independently were higher-level lesion (>L4, p = 0.001) and the development of clubfoot deformity after fetal intervention (p = 0.026). Despite the observed improved ambulatory status, structured evaluation of coordinative skills revealed that the majority of independent ambulators and all children that require assistive devices to walk experience significant deficits in lower extremity coordination.

CONCLUSIONS

We observed that fMMC surgery in this highly selective population results in better than predicted LENF at birth and short-term ambulatory status. However, fMMC toddlers continue to demonstrate deficits in movement coordination that are characteristic for children with spina bifida.

Genetic association of the activin A receptor gene (ACVR2A) and pre-eclampsia

Pre-eclampsia is a common serious disorder of human pregnancy, which is associated with significant maternal and perinatal morbidity and mortality. The suspected aetiology of pre-eclampsia is complex, with susceptibility being attributable to multiple environmental factors and a large genetic component. Recently, we reported significant linkage to chromosome 2q22 in 34 Australian/New Zealand (Aust/NZ) pre-eclampsia/eclampsia families, and activin A receptor type IIA (ACVR2A) was identified as a strong positional candidate gene at this locus. In an attempt to identify the putative risk variants, we have now comprehensively re-sequenced the entire coding region of the ACVR2A gene and the conserved non-coding sequences in a subset of 16 individuals from these families. We identified 45 single nucleotide polymorphisms (SNPs), with 9 being novel. These SNPs were genotyped in our total family sample of 480 individuals from 74 Aust/NZ pre-eclampsia families (including the original 34 genome-scanned families). Our best associations between ACVR2A polymorphisms and pre-eclampsia were for rs10497025 (P = 0.025), rs13430086 (P = 0.010) and three novel SNPs: LF004, LF013 and LF020 (all with P = 0.018). After correction for multiple hypothesis testing, none of these associations reached significance (P > 0.05). Based on these data, it remains unclear what role, if any, ACVR2A polymorphisms play in pre-eclampsia risk, at least in these Australian families. However, it would be premature to rule out this gene as significant associations between ACVR2A SNPs and pre-eclampsia have recently been reported in a large Norwegian (HUNT) population sample.

Reversal of hindbrain herniation after maternal-fetal surgery for myelomeningocele subsequently impacts on brain stem function

The aim of our study was to delineate whether the reversal of hindbrain herniation (HH) following fetal myelomeningocele (fMMC) closure subsequently reduces the incidence and severity of HH-associated brainstem dysfunction (BSD). Prior to the NIH-sponsored Management of Myelomeningocele Study (MOMS) trial, 54 children underwent fMMC closure at our institution. Forty-eight (89%) families participated in a structured survey focusing on HH-associated BSD (e.g., apnea, neurogenic dysphagia [ND], gastro-esophageal reflux disease [GERD], neuro-ophthalmologic disturbances [NOD]). Median age at follow-up was 72 months (range: 46-98). Fifty-percent required shunting. HH-related symptoms were completely absent in 15 (63%) non-shunted and 10 (42%) shunted children (P=0.15). No HH-related death occurred and none developed severe persistent cyanotic apnea. ND was reported in 2 (8%) non-shunted and 9 (38%) shunted infants (P=0.03). Mild GERD (medically managed) developed in 2 (8%) without and 6 (25%) with shunt placement (P=0.24). NOD was found in 6 (25%) and 13 (54%) of non-shunted and shunted children, respectively (P=0.07). The majority of fMMC children developed no or only mild BSD at follow-up. Our data support the hypothesis that neurodevelopmental deficits associated with MMC are at least partially acquired and that reversal of HH following fMMC surgery may help to reduce the incidence and severity of BSD.

Intradural inclusion cysts following in utero closure of myelomeningocele: clinical implications and follow-up findings

OBJECT

The goal in this study was to evaluate the incidence and clinical implications of the development of cutaneously derived intradural inclusion cysts (ICs) following fetal myelomeningocele (fMMC) closure.

METHODS

Retrospective databases and responses to a parental questionnaire were reviewed to determine the incidence, clinical presentation, and outcomes of fMMCs in children in whom ICs developed at follow-up.

RESULTS

Prior to the National Institutes of Health (NIH)-sponsored Management of Myelomeningocele Study (MOMS), 54 patients underwent fMMC closure at the authors' institution. Sixteen (30%) presented with symptomatic tethered cord syndrome (TCS) at a median age of 27 months (range 4-93 months). Ten (63%) of the 16 (19% of the total) developed TCS in association with an intradural IC. In 9 (90%) of 10 patients, the IC was seen on preoperative MR imaging, and in 1 it was found during surgery. Four additional children (7% of the total) with evidence of an IC on surveillance MR imaging are currently asymptomatic at 94, 84, 60, and 60 months of age, respectively. All but 1 (an L-3 level lesion) IC developed in infants with L-4 and L-5 defects. After cyst removal, 6 children are asymptomatic at a median follow-up of 36 months (range 12-63 months). Following IC removal, 4 children lost normal bladder function and now require clean intermittent catheterization, and 1 lost normal leg function and now requires a walking aid for ambulation. Histologically, 8 lesions were dermoid, 1 was an epidermoid, and 1 was a mixed dermoid-epidermoid IC. Three patients developed another IC and required its removal at 24, 39, and 51 months, respectively. One required another tethered cord release within 57 months after IC removal.

CONCLUSIONS

Cutaneously derived intradural ICs can develop following fMMC surgery. Deterioration of bladder function, risk of recurrence, and loss of lower-extremity function appear to be the most important long-term complications of IC in children with fMMCs. The ongoing NIH-sponsored MOMS may help determine whether children with fMMC are at increased risk of IC development compared with children treated with postnatal MMC closure. Parents seeking fMMC closure should be informed about the possibility of IC formation and the potential clinical consequences.

Passive acoustic detection of deep-diving beaked whales

Beaked whales can remain submerged for an hour or more and are difficult to sight when they come to the surface to breathe. Passive acoustic detection (PAD) not only complements traditional visual-based methods for detecting these species but also can be more effective because beaked whales produce clicks regularly to echolocate on prey during deep foraging dives. The effectiveness of PAD for beaked whales depends not only on the acoustic behavior and output of the animals but also on environmental conditions and the quality of the passive sonar implemented. A primary constraint on the range at which beaked whale clicks can be detected involves their high frequencies, which attenuate rapidly, resulting in limited ranges of detection, especially in adverse environmental conditions. Given current knowledge of source parameters and in good conditions, for example, with a wind speed of 2 ms, a receiver close to the surface should be able to detect acoustically Cuvier's beaked whales with a high probability at distances up to 0.7 km, provided the listening duration exceeds the deep dive interval, about 2.5 h on average. Detection ranges beyond 4 km are unlikely and would require low ambient noise or special sound propagation conditions.

Macroalgal introductions by hull fouling on recreational vessels: seaweeds and sailors

Macroalgal invasions in coastal areas have been a growing concern during the past decade. The present study aimed to assess the role of hull fouling on recreational yachts as a vector for macroalgal introductions. Questionnaire and hull surveys were carried out in marinas in France and Spain. The questionnaires revealed that the majority of yacht owners are aware of seaweed introductions, usually undertake short range journeys, dry dock their boat at least once a year, and use antifouling paints. The hull survey showed that many in-service yachts were completely free of macroalgae. When present, fouling assemblages consisted mainly of one to two macroalgal species. The most commonly found species was the tolerant green seaweed Ulva flexuosa. Most of the other species found are also cosmopolitan and opportunistic. A few nonnative and potentially invasive Ceramiales (Rhodophyta) were found occasionally on in-service yachts. On the basis of the information gathered during interviews of yacht owners in the surveyed area, these occurrences are likely to be uncommon. However they can pose a significant risk of primary or secondary introductions of alien macroalgal species, especially in the light of the increase in yachting activities. With large numbers of recreational yachts and relatively rare occurrences of nonnative species on hulls, comprehensive screening programs do not seem justified or practical. The risks of transferring nonnative species may, however, be minimized by encouraging the behaviors that prevent fouling on hulls and by taking action against neglected boats before they can act as vectors.

Fetal tracheal occlusion for severe congenital diaphragmatic hernia in humans: a morphometric study of lung parenchyma and muscularization of pulmonary arterioles

OBJECTIVE

The aim of this study is to examine structure of lung parenchyma (Pp) and muscularization of pulmonary arterioles (PAs) in human fetuses that underwent tracheal occlusion (TO) therapy for severe congenital diaphragmatic hernia (CDH).

MATERIAL

Fifteen fetuses underwent TO, with 5 survivors (Am J Obstet Gynecol. 2000:183;1059-1066). Paraffin-embedded lung specimens from 7 of 10 nonsurvivors (CDH-TO) and 6 age-matched fetuses (CDH) were available for morphometric analysis, which included measurements of point fraction of lung Pp and surface density. The PAs were categorized according to external diameter (<70 microm and 70 <or= 140 microm). Percent medial wall thickness (%MWT) was calculated by dividing raw measurements of MWT by external diameter.

RESULTS

Gestational age at TO was 27.6 +/- 0.9 weeks with a mean duration of TO of 32.6 +/- 6.8 days. Gestational age at delivery (CDH-TO 31.9 +/- 0.9 vs CDH 35.4 +/- 1.8 weeks; P = .18) and postnatal survival time (CDH-TO 20.5 +/- 6.0 vs CDH 18.6 +/- 7.8 days; P = .85) were not significantly different between groups. Tracheal occlusion significantly increased the lung-to-body weight ratio (CDH-TO 13.0 +/- 2.2 vs CDH 6.6 +/- 0.9; P = .02). Tracheal occlusion tended to decrease right-lung Pp (CDH-TO 54.6% +/- 2.6% vs CDH 65.7% +/- 5.9%; P = .05), whereas left-lung Pp was not different between groups (CDH-TO 63.0% +/- 3.5% vs CDH 66.7% +/- 4.1%; P = .51). Surface density of airspaces was not different between groups in either left (CDH-TO 171.3 +/- 16.1 cm(-1) vs CDH 151.1 +/- 8.1 cm(-1); P = .34) or right (CDH-TO 172.0 +/- 10.6 cm(-1) vs CDH 160.8 +/- 3.6 cm(-1); P = .33) lungs. The %MWT in small and large PA was similar between groups.

CONCLUSIONS

Open prenatal TO in human fetuses increased lung growth, as evidenced by an increase in lung weight, but did not improve parenchymal structure or muscularization of PAs.

Cross-species replication of a resistin mRNA QTL, but not QTLs for circulating levels of resistin, in human and baboon

Resistin has been associated with inflammation and risk for cardiovascular disease. We previously reported evidence of a QTL on chromosome 19p13 affecting the abundance of resistin (RETN) mRNA in the omental adipose tissue of baboons (L0D score 3.8). In this study, whole genome transcription levels were assessed in human lymphocyte samples from 1240 adults participating in the San Antonio Family Heart Study, using the Sentrix Human-6 Expression Beadchip. Lymphocytes were surveyed, as it has been proposed that their expression levels may reflect those in harder to ascertain tissues, such as adipose tissue, that are thought to be more directly relevant to disease procesn was conducted to detect loci affecting RETN mRNA levels. We obtained significant evidence for a QTL influencing the RETN expression (LOD score 10.7) on chromosome 19p. This region is orthologous/homologous to the region previously localized on baboon chromosome 19. The strongest positional candidate gene in this region is the structural gene for resistin, itself. We also found evidence for a QTL influencing resistin protein levels (LOD score 5.3) on chromosome 14q. This differs from our previously reported QTL on chromosome 18 in baboons. The different QTLs for circulating protein suggests that post-translational processing and turnover may be influenced by different or multiple genes in baboons and humans. The parallel findings of a cis-eQTL for RETN mRNA in baboon omental tissue and human lymphocytes lends support to the strategy of using lymphocyte gene expression levels as a surrogate for gene expression levels in other tissues.

Prenatal ultrasonographic gastrointestinal abnormalities in fetuses with gastroschisis do not correlate with postnatal outcomes

PURPOSE

In the setting of gastroschisis, the clinical significance of prenatal ultrasound findings of secondary changes in bowel appearance remains unknown. The purpose of this study was to correlate prenatal identification of additional gastrointestinal sonographic abnormalities with postnatal clinical outcome.

METHODS

A retrospective review was conducted on 64 fetuses with a prenatal diagnosis of gastroschisis treated at the Children's Hospital of Philadelphia from 2000 to 2007. Postnatal outcomes were compared between newborns with additional sonographic gastrointestinal abnormalities and those without secondary changes to the bowel appearance.

RESULTS

Thirty (47%) patients had at least one gastrointestinal abnormality (eg, bowel dilatation, echogenic bowel, thickened bowel, matted bowel, herniation of the stomach through the abdominal wall defect, or segmental loss of bowel peristalsis) on prenatal ultrasound. There were no significant differences between groups with respect to the time to initial and full enteral nutrition, total hospital stay, requirement for ventilator support, central line infection rates, reoperation rates, or mortality.

CONCLUSIONS

In the setting of gastroschisis, isolated findings of gastrointestinal abnormalities on prenatal ultrasound do not correlate with adverse postnatal outcome.

Classification of broadband echoes from prey of a foraging Blainville's beaked whale

Blainville's beaked whales (Mesoplodon densirostris) use broadband, ultrasonic echolocation signals with a -10 dB bandwidth from 26 to 51 kHz to search for, localize, and approach prey that generally consist of mid-water and deep-water fishes and squid. Although it is well known that the spectral characteristics of broadband echoes from marine organisms vary as a function of size, shape, orientation, and anatomical group, there is little evidence as to whether or not free-ranging toothed whales use spectral cues in discriminating between prey and nonprey. In order to study the prey-classification process, a stereo acoustic tag was deployed on a Blainville's beaked whale so that emitted clicks and the corresponding echoes from targets in the water could be recorded. A comparison of echoes from targets apparently selected by the whale and those from a sample of scatterers that were not selected suggests that spectral features of the echoes, target strengths, or both may have been used by the whale to discriminate between echoes. Specifically, the whale appears to favor targets with one or more nulls in the echo spectra and to seek prey with higher target strengths at deeper depths.

Outcomes after postnatal resection of prenatally diagnosed asymptomatic cystic lung lesions

BACKGROUND

Symptomatic congenital lung lesions require surgical resection, but the management of asymptomatic lung lesions is controversial. Some surgeons advocate observation because of concerns about potential operative morbidity and mortality, as well as a lack of long-term follow-up information. On the other hand, malignant degeneration, pneumonia, and pneumothorax are known consequences of cystic lung lesions. This study aims to assess the safety of resection for asymptomatic lung lesions that were diagnosed before birth.

METHODS

A retrospective review of all patients with prenatally diagnosed lung lesions at Children's Hospital of Philadelphia (Philadelphia, Penn) was performed from 1996 to 2005. The perioperative course of patients who were asymptomatic was analyzed.

RESULTS

One hundred five complete records of children with asymptomatic lesions were reviewed. Overall mortality was 0% and morbidity was 6.7% including 2.9% significant postoperative air leak and 3.8% transfusion requirement. Nine patients had a pathologic diagnosis that differed from preoperative radiological findings, and 9 patients had additional pathologic findings.

CONCLUSION

This series demonstrates that surgery can be performed safely on patients who were asymptomatic with congenital cystic adenomatoid malformation of the lung and other types of lung lesions with no mortality and minimal morbidity. The frequency of disparate pathologic diagnoses and the potential for development of malignancy and other complications support the argument for early resection.

Antenatal diagnosis and management of congenital cystic adenomatoid malformation

One of the most enigmatic pulmonary lesions encountered in the prenatal period is the congenital cystic adenomatoid malformation (CCAM). This review presence current thinking on pathogenesis, prenatal assessment, fetal intervention, and management for this pulmonary malformation. Careful delivery planning by utilizing a multidisciplinary approach will optimize neonatal outcomes.

Pregnancy outcomes following bipolar umbilical cord cauterization for selective termination in complicated monochorionic multiple gestations

OBJECTIVE

To review pregnancy and childhood outcomes following selective termination by ultrasound guided bipolar umbilical cord cauterization (UCC) in complicated monochorionic multifetal pregnancies.

STUDY DESIGN

Consenting patients (27 of 49, 55%) had review of pregnancy history and pediatric development in the surviving twin following selective UCC.

RESULTS

UCC was performed at 21.2 +/- 2.8 weeks gestational age, followed by a liveborn delivery (n = 28) at 34.4 +/- 4.7 weeks. Mean birth weight was 2,218 +/- 926 g. Complications included preterm labor (25.0%), premature rupture of membranes (17.8%), placental abruption (10.7%) and chorioamnionitis (7.1%). Perinatal mortality was 10.3% in continuing fetuses. However, 96.2% of pregnancies achieved livebirths with 96% of neonates showing apparently normal development between ages 1.5 and 5 years.

CONCLUSION

Bipolar UCC is a reasonably safe and effective treatment for selective termination in complicated monochorionic pregnancies.

'Megapclicks': acoustic click trains and buzzes produced during night-time foraging of humpback whales (Megaptera novaeangliae)

Humpback whales (Megaptera novaeangliae) exhibit a variety of foraging behaviours, but neither they nor any baleen whale are known to produce broadband clicks in association with feeding, as do many odontocetes. We recorded underwater behaviour of humpback whales in a northwest Atlantic feeding area using suction-cup attached, multi-sensor, acoustic tags (DTAGs). Here we describe the first recordings of click production associated with underwater lunges from baleen whales. Recordings of over 34000 'megapclicks' from two whales indicated relatively low received levels at the tag (between 143 and 154dB re 1 microPa pp), most energy below 2kHz, and interclick intervals often decreasing towards the end of click trains to form a buzz. All clicks were recorded during night-time hours. Sharp body rolls also occurred at the end of click bouts containing buzzes, suggesting feeding events. This acoustic behaviour seems to form part of a night-time feeding tactic for humpbacks and also expands the known acoustic repertoire of baleen whales in general.

Liver position and lung-to-head ratio for prediction of extracorporeal membrane oxygenation and survival in isolated left congenital diaphragmatic hernia

OBJECTIVE

The purpose of this study was to determine the ability of liver position and lung-to-head ratio to predict outcome in isolated left congenital diaphragmatic hernia.

STUDY DESIGN

We reviewed prenatal studies and postnatal outcomes of congenital diaphragmatic hernia between January 1996 and January 2006.

RESULTS

Eighty-nine patients received prenatal and postnatal care at 1 institution. In fetuses with liver up, extracorporeal membrane oxygenation was required in 39 of 49 fetuses (80%), compared with 10 of 40 fetuses (25%) for those with liver down (P < .0001). Overall survival rate was 45%, compared with 93% for those with liver down (P < .00005). Low lung-to-head ratio (<1.0) predicted increased incidence of extracorporeal membrane oxygenation (75%; P = .036) and lower survival (35%; P = .0003). However, when measured at <24 weeks of gestation, lung-to-head ratio was not predictive of outcome (extracorporeal membrane oxygenation, P = .108; survival, P = .150); liver position remained highly predictive (extracorporeal membrane oxygenation, P = .006; survival, P = .001).

CONCLUSION

Liver position is the best prenatal predictor of outcome in isolated left congenital diaphragmatic hernia. Lung-to-head ratio alone should not be used to counsel families regarding mid gestational management choices.

The twin-twin transfusion syndrome: spectrum of cardiovascular abnormality and development of a cardiovascular score to assess severity of disease

OBJECTIVE

Current means of grading twin-twin transfusion syndrome does not characterize cardiovascular aspects adequately. We sought to develop a score that describes the magnitude of cardiovascular severity in twin-twin transfusion syndrome.

STUDY DESIGN

Fetal echocardiograms of 150 monochorionic/diamniotic twins were reviewed. Blinded to Quintero stage, we applied a cardiovascular score to each twin set and compared it to the Quintero grade. The score is a composite of variables that include ventricular hypertrophy, dilation, function, valve regurgitation, great artery size, and diastolic properties in the recipient and umbilical artery flow in the donor. Doppler indices of vascular and ventricular function were measured.

RESULTS

Mean age was 21 +/- 3 weeks. Discrepancy was noted in degree of severity between Quintero and cardiovascular stages. The score correlated well with myocardial performance index of the recipient right ventricle (r2 = .65).

CONCLUSION

We describe the spectrum of cardiovascular abnormalities that are seen in twin-twin transfusion syndrome and propose a scoring system for assessment of severity.

Prenatally diagnosed fetal lung lesions with associated conotruncal heart defects: Is there a genetic association?

Congenital lung malformation can easily be diagnosed by prenatal ultrasound. Associated extrapulmonary malformations such as heart defects and chromosomal aberrations are rare.

OBJECTIVE

The objective of this study was to describe the natural history, outcome and other associated malformations in fetuses with lung lesions and an associated heart defect.

METHODS

Retrospective analysis of 4 cases of prenatally diagnosed fetal CCAMs and hybrid lesions with an associated heart defect and review of 8 cases in the literature.

RESULTS

At a single referral center 1.9% of the fetuses with Congenital cystic adenomatoid malformation (CCAM) were diagnosed with an associated heart defect. Seven of the total 12 cases (58%) reviewed had a conotruncal heart abnormality. Chromosomal abnormalities were found in 5 (42%) of the cases.

CONCLUSION

This retrospective review shows that karyotyping in fetal lung lesions with an associated heart defect or isolated large lung lesions is indicated. It also suggests that there is a subpopulation of fetuses with CCAMs who have conotruncal heart defects. This finding may suggest a common genetic background.

Postnatal Chest Wall Deformities after Fetal Thoracoamniotic Shunting for Congenital Cystic Adenomatoid Malformation

OBJECTIVES

Large macrocystic congenital cystic adenomatoid malformations (CCAMs) can be treated with thoracoamniotic (TA) shunting to reduce CCAM volume. Two CCAM fetuses treated with TA shunt had postnatal radiographic rib deformities.

STUDY DESIGN

Retrospective review of prenatal TA shunting for large macrocystic CCAMs evaluated for the presence of rib deformities. Comparison groups not eligible for TA shunting included nonshunted CCAMs resected postnatally (group A) and size-matched nonshunted CCAMs resected postnatally (group B).

RESULTS

Chest wall abnormalities were identified in 77% of newborns ranging from severe concavity and fractures (in two fetuses shunted at 18 and 20 weeks of gestation) to rib thinning compared to comparison groups A and B. The severity of chest wall deformity correlated with earlier gestational age at shunting.

CONCLUSIONS

TA shunting at less than 21 weeks of gestational age may result in postnatal chest wall deformity. This observation should be discussed during counseling for this procedure.

Effect of Maternal Betamethasone Administration on Prenatal Congenital Cystic Adenomatoid Malformation Growth and Fetal Survival

OBJECTIVE

To evaluate the effect of prenatal steroid treatment on the growth of congenital cystic adenomatoid malformations (CCAM) and survival in affected fetuses not amenable to other percutaneous ultrasound-guided prenatal interventions.

METHODS

A retrospective review of patients with a CCAM or hybrid lesion treated with two maternal prenatal betamethasone injections was performed. Patients receiving cyst aspiration or thoracoamniotic shunting at the time of or after steroid administration were excluded. Growth rates and survival data were compared to historical non-steroid treated controls.

RESULTS

Eleven patients were treated with prenatal steroids (10 microcystic and 1 macrocystic). Survival was 100% in fetuses with hydrops (5/5) or a CCAM volume ratio (CVR) >1.6 (7/7) at the time of steroid administration. This compares to a mortality of 100 and 56.2% respectively in historical non-treated controls. Resolution of hydrops was seen in 80% (4/5) of steroid-treated patients. CCAM growth rates were variable after steroid administration. However, when compared to historical data where CVR and CCAM volume have been documented to increase until 28 weeks' gestation, the CVR and CCAM volume growth rates decreased in 72.73% and 50% of patients respectively from the time of steroid administration to 28 weeks' gestation.

CONCLUSIONS

In the fetus with a CCAM, the presence of hydrops fetalis or a CVR >1.6 is indicative of poor fetal outcome without prenatal intervention. The observed effect of antenatal steroid treatment on CCAM growth is variable, but its potential to improve survival in these high-risk groups is encouraging and warrants further controlled evaluations.

Does a Myelomeningocele Sac Compared to No Sac Result in Decreased Postnatal Leg Function following Maternal Fetal Surgery for Spina Bifida Aperta?

OBJECTIVE

A fetus with large sac S1 myelomeningocele (MMC) but bilateral talipes prompted the question, 'Does the presence or size of an MMC sac affect postnatal leg function?'

STUDY DESIGN

An MMC database with prenatal, birth, and a minimum of 1-year follow-up evaluation was reviewed. All fetuses had in-utero MMC repair at 20 + 0 to 25 + 6 weeks at a single institution. Fifty-four fetuses had prenatal evaluation, with 48 children completing a birth and a 1-year evaluation of leg function.

RESULTS

An MMC sac was present in 38/54 (70%) of fetuses evaluated in-utero and had been present in 35/48 (73%) of children evaluated at 1 year of age. Although leg function evaluated at 1 year was better than expected in the 'no sac' group (p = 0.059), this did not reach statistical significance.

CONCLUSION

The presence of an MMC sac may increase postnatal lower limb morbidity.

Gastroschisis: Growth Patterns and a Proposed Prenatal Surveillance Protocol

OBJECTIVE

To assess intrauterine growth for fetuses with gastroschisis using retrospective serial ultrasound assessment from fetuses diagnosed prenatally with gastroschisis. The growth assessment could be available as a prospective tool to direct an antepartum fetal surveillance protocol.

METHODS

This is a retrospective review of all cases of gastroschisis evaluated prenatally at a single institution between February 1996 and March 2002. Charts were reviewed for serial ultrasound assessment, gestational age at delivery, mode of delivery, and birth weight. Growth assessment was determined for abdominal circumference, biparietal diameter, head circumference, femur length, and estimated fetal weight (IRB No. 2002-1-2648).

RESULTS

Forty patients had delivered by March 2002. One hundred and two ultrasound reports were reviewed. Gastroschisis growth curves showed that the 50th percentile was shifted to the right when compared to normal growth curves for abdominal circumference, biparietal diameter, head circumference, and femur length. The average birth weight was 2,359 g. Compared with a standard population, 44% (16/36) were below the 5th percentile, 61% (22/36) were below the 10th percentile, and 95% (34/36) were below the 50th percentile for gestational age. The average gestational age at delivery was 36.3 weeks. Mothers were nulliparous in 78%, with a mean age of 21.3 years.

CONCLUSIONS

(1) Fetuses with gastroschisis show a symmetric intrauterine growth restriction pattern consistent with early development of growth delay; (2) the 50th percentile biometry measurements for the gastroschisis population are shifted to the right on normal fetal growth curves; (3) the birth weight is at or below the 10th percentile in 61% of the newborns with gastroschisis, and (4) an antepartum surveillance protocol is proposed based on growth patterns of fetuses with gastroschisis.

Prenatal Diagnosis and Postnatal Management of Diffuse Congenital Hyperinsulinism: A Case Report

We present the first case of the prenatal diagnosis of congenital hyperinsulinism based on the genetic analysis of known family mutations in the SUR1 gene. An amniocentesis was performed at 16 weeks gestation at which time two mutations in the SUR1 gene were identified consistent with the diagnosis of diffuse hyperinsulinism. The mother was transported to our facility and underwent an elective caesarian section at 38 weeks gestation. The diagnosis was confirmed and treatment was initiated within the first minutes of life. After a short course of failed medical management, the patient underwent a 98% pancreatectomy with subsequent good glycemic control. This case highlights the benefits of the timely in utero diagnosis of hyperinsulinism by mutational analysis.

Identification of two novel quantitative trait loci for pre-eclampsia susceptibility on chromosomes 5q and 13q using a variance components-based linkage approach

Pre-eclampsia/eclampsia (PE/E) is a common and serious disorder of human pregnancy that is associated with substantial maternal and perinatal morbidity and mortality. The suspected aetiology of PE/E is complex, with susceptibility being attributable to multiple environmental factors and a large genetic component. By assuming that the underlying liability towards PE/E susceptibility is inherently quantitative, any PE/E susceptibility gene would represent a quantitative trait locus (QTL). This assumption enables a more refined and powerful variance components procedure using a threshold model for our PE/E statistical analysis. Using this more efficient linkage approach, we have now re-analysed our previously completed Australian/New Zealand genome scan data to identify two novel PE/E susceptibility QTLs on chromosomes 5q and 13q. We have obtained strong evidence of linkage on 5q with a peak logarithm-of-odds (LOD) score of 3.12 between D5S644 and D5S433 [at approximately 121 centimorgan (cM)] and strong evidence of linkage on 13q with a peak LOD score of 3.10 between D13S1265 and D13S173 (at approximately 123 cM). Objective identification and prioritization of positional candidate genes using the quantitative bioinformatics program GeneSniffer revealed highly plausible PE/E candidate genes encoding aminopeptidase enzymes and a placental peptide hormone on the 5q QTL and two type IV collagens on the 13q QTL regions, respectively.