Risk Factors and Prevalence of Limb Deficiencies Associated With Amniotic Band Sequence: A Population-based Case-control Study.

BACKGROUND: Limb deficiencies associated with amniotic bands comprise a wide range of congenital anomalies. The association of maternal medication and the risk of amniotic band sequence (ABS) has not yet been addressed. METHODS: This nationwide population-based case-control study used national registers on congenital anomalies, births and induced abortions, cross-linked with information on maternal prescription medicine use obtained from the registers on Reimbursed Drug Purchases and Medical Special Reimbursements. All cases with congenital limb deficiency associated with amniotic bands born between 1996 and 2008 were included in the study. Five controls without limb deficiency matched for residency and time of conception were randomly selected from the Medical Birth Register. RESULTS: In total, 106 children with limb deficiency associated with ABS were identified and compared with 530 matched controls. Young maternal age (less than 25 y) increased the risk of limb deficiencies [odds ratio=1.72; 95% confidence interval (CI): 1.06, 2.80]. Primiparity was also associated with increased risk [adjusted odds ratio (aOR)=2.42; 95% CI: 1.52, 3.88]. After adjusting for maternal age, pregestational diabetes, and parity, maternal use of beta-blockers (adjusted OR=24.2; 95% CI: 2.57, 228) and progestogens (adjusted OR=3.79; 95% CI: 1.38, 10.4) during the first trimester of pregnancy significantly increased the risk of limb deficiencies associated with amniotic bands. CONCLUSIONS: Primiparity significantly increased the risk of limb defects associated with amniotic bands. Also, a novel association on increased risk of ABS with maternal use of progestogens or beta-blockers during the first trimester of pregnancy was observed. LEVEL OF EVIDENCE: Level III.

Prevalence, risk factors, and outcome of postprocedural amniotic band disruption sequence after fetoscopic laser surgery in twin-twin transfusion syndrome: a large single-center case series.

BACKGROUND: Postprocedural amniotic band disruption sequence is a condition that is associated with intrauterine interventions, and it is characterized by a constriction of the limbs or umbilical cord by fibrous strands, leading to edema, amputation, and/or fetal demise. OBJECTIVE: To evaluate the prevalence of, risk factors for, and the outcome of postprocedural amniotic band disruption sequence after fetoscopic laser surgery in twin-twin transfusion syndrome cases. STUDY DESIGN: All consecutive cases of twin-twin transfusion syndrome treated with fetoscopic laser coagulation of the vascular anastomoses at our center between January 2002 and March 2019 were included in the study. The occurrence of postprocedural amniotic band disruption sequence in these cases was recorded, and the potential risk factors were analyzed. RESULTS: Postprocedural amniotic band disruption sequence was detected, at birth, in 2.2% (15/672) of twin-twin transfusion syndrome cases treated with fetoscopic laser surgery, in both the recipients (10/15, 67%) and the donors (5/15, 33%). Postprocedural amniotic band disruption sequence primarily affected the lower extremities (11/15, 73%) and, less frequently, the upper extremities (2/15, 13%), both the upper and lower extremities (1/15, 7%), or the umbilical cord (1/15, 7%). Postprocedural amniotic band disruption sequence led to the amputation of toes in 5 of 15 cases (33%) and resulted in fetal demise because of constriction of the umbilical cord in 1 case (7%). The independent risk factors identified for postprocedural amniotic band disruption sequence were lower gestational age at laser surgery (odds ratio per week, 1.43; 95% confidence interval, 1.12-1.79; P=.003) and the presence of postprocedural chorioamniotic membrane separation on antenatal ultrasound examination (odds ratio, 41.66; 95% confidence interval, 5.44-319.25; P<.001). CONCLUSION: The prevalence of postprocedural amniotic band disruption sequence is low, but, when present, it may lead to severe consequences, with amputation of extremities or fetal demise occurring in more than one-third of the cases. Lower gestational age at the time of laser therapy and chorioamniotic membrane separation are independent risk factors for the postprocedural amniotic band disruption sequence.

Effects and outcomes of septostomy in twin-to-twin transfusion syndrome after fetoscopic laser therapy.

BACKGROUND: To evaluate the incidence and outcomes of septostomy in twin-to-twin transfusion syndrome (TTTS) after fetoscopic laser therapy. METHODS: A retrospective analysis of TTTS postlaser septostomy between 2005 and 2018 was performed. Postlaser septostomy was diagnosed using both (1) a free-floating intertwin membrane flap visible on ultrasound examination and (2) the rapid equalization of amniotic fluid maximum vertical pocket in the donor and recipient amniotic sacs observed after laser therapy. Perinatal survival, neonatal brain image anomaly, gestational age at operation and birth, incidence of premature rupture of membranes (PROM) within 3 weeks after operation, pseudoamniotic band syndrome, and cord entanglement were evaluated. RESULTS: In the 159 TTTS cases included, 12 had postlaser septostomy. Relative to the group without septostomy, the septostomy group had a lower total fetal survival rate (54.2% vs 73.6%, p = 0.041), an earlier mean gestational age at delivery (27.8 vs 34.4 weeks, p = 0.009), a higher risk of PROMs within 3 weeks after operation (33.3% vs 5.4%, p = 0.004), a higher cord entanglement rate (16.7% vs 0%, p = 0.005), and a higher brain image anomaly rate (23.0% [3/13] vs 5.0% [11/218], p = 0.035). After considering the severe Quintero stages (stage III and IV), postlaser septostomy was the only variable [p = 0.003, odds ratio = 5.1] to predict neonatal brain image anomaly. Postlaser septostomy combined with severe Quintero stages could predict PROMs within 3 weeks after laser therapy [p = 0.001, odds ratio = 14.1 and p = 0.03, odds ratio = 5.4, respectively] and delivery before the gestational age of 28 weeks [p = 0.017, odds ratio = 4.5 and p = 0.034, odds ratio = 2.3, respectively]. The risk of pseudoamniotic band syndrome was not increased by postlaser septostomy in this case series. CONCLUSIONS: Postlaser septostomy in TTTS was associated with poorer fetal survival and more adverse perinatal outcomes even after considering severe Quintero stages before laser therapy. Efforts should be made to prevent septostomy during laser therapy, and septostomy as the primary method to treat TTTS is not advisable.

Limb body wall complex: Its delineation and relationship with amniotic bands using clustering methods.

BACKGROUND: Despite the numerous reports on the limb body wall complex (LBWC), this association has never been adequately defined. Amniotic bands (AB) are frequently present but their role remains unclear. Since most reports were based on clinical and often subjective diagnoses, the aim of this work was to define LBWC and the role of AB, minimizing subjectivity. METHODS: Data were obtained from the ECLAMC maternity hospitals network database. A total of 450 live and stillborn infants, born during 1967-2013, with AB or the LBWC were selected. A hierarchical cluster analysis was used to classify cases into homogeneous groups (sharing similar associated defects); robustness of the classification was confirmed with a discriminant analysis. The frequency of associated defects was compared among groups; those whose frequency differed significantly were included in a logistic regression to establish their association within each group. RESULTS: The cluster analysis identified two groups: a body wall defect (BWD) predominating in one, AB in the other. These groups were further divided into: BWD (cases with only BWD), AB (with only AB), BWD + AB, and NONE (with neither). Association with caudal defects and lower limb amelia was observed for BWD, with cephalic defects and upper limb amputations for BWD + AB. CONCLUSIONS: The results, obtained with the least possible subjectivity, indicated that BWD and BWD + AB are different conditions. Since BWD specifically associates with amelia, we propose that this defect and not any limb deficiency should be considered as inclusion criterium and that it should be included in the BWD acronym as LBWC.

Secuencia de bandas amnióticas, una actualización / An update on amniotic bands sequence

La secuencia de bandas amnióticas es un desorden congénito caracterizado por anomalías craneofaciales, de la pared corporal y de las extremidades que pueden asociarse con bandas fibrosas fetoplacentarias. Su prevalencia ha sido reportada entre 0,19 y 8,1 por 10 000 nacimientos. Diversas teorías han tratado de explicar su etiología, sin embargo, ninguna, en forma individual, sustenta todas y cada una de las anomalías observadas, por lo que se ha considerado una entidad multifactorial. La identificación de anomalías (pre-yposnatalmente) sugestivas de secuencia de bandas amnióticas permite el abordaje diagnóstico para efectuar intervenciones terapéuticas oportunas que posibiliten la liberación de bandas amnióticas mediante fetoscopia con recuperación de la perfusión de la porción distal de la extremidad involucrada o bien la reparación quirúrgica posnatal y para otorgar asesoramiento genético. Este artículo ofrece una actualización sobre aspectos epidemiológicos, teorías etiológicas, factores de riesgo, características clínicas, diagnóstico (que incluye el diagnóstico prenatal), asesoramiento genético, abordaje terapéutico y pronóstico de esta entidad.

Amniotic bands sequence is a congenital disorder characterized by craniofacial, body wall, and limb anomalies that may be associated with fetal-placental fibrous bands. Its prevalence has been reported to range from 0.19 to 8.1 per 10 000births. Different theories have attempted to explain the etiology of amniotic band sequence; however, none has individually been able to support each and every defect observed, so it has been considered to be a multifactorial condition. The (pre- and post-natal) identification of anomalies suggestive of amniotic band sequence is useful for the diagnostic approach and implementation of timely therapeutic interventions favoring the release of the amniotic bands using fetoscopy with recovery of the involved distal limb perfusion, or else the possibility of performing a post-natal surgical repair. It is also helpful to provide genetic counseling. This article offers an update on the epidemiological aspects, etiological theories, risk factors, clinical characteristics, diagnosis (including antenatal diagnosis), genetic counseling, therapeutic approach, and prognosis of amniotic bands sequence.

An update on amniotic bands sequence. / Secuencia de bandas amnióticas, una actualización.

Amniotic bands sequence is a congenital disorder characterized by craniofacial, body wall, and limb anomalies that may be associated with fetalplacental fibrous bands. Its prevalence has been reported to range from 0.19 to 8.1 per 10 000 births. Different theories have attempted to explain the etiology of amniotic band sequence; however, none has individually been able to support each and every defect observed, so it has been considered to be a multifactorial condition. The (pre- and post-natal) identification of anomalies suggestive of amniotic band sequence is useful for the diagnostic approach and implementation of timely therapeutic interventions favoring the release of the amniotic bands using fetoscopy with recovery of the involved distal limb perfusion, or else the possibility of performing a post-natal surgical repair. It is also helpful to provide genetic counseling. This article offers an update on the epidemiological aspects, etiological theories, risk factors, clinical characteristics, diagnosis (including antenatal diagnosis), genetic counseling, therapeutic approach, and prognosis of amniotic bands sequence.

La secuencia de bandas amnióticas es un desorden congénito caracterizado por anomalías craneofaciales, de la pared corporal y de las extremidades que pueden asociarse con bandas fibrosas fetoplacentarias. Su prevalencia ha sido reportada entre 0,19 y 8,1 por 10 000 nacimientos. Diversas teorías han tratado de explicar su etiología, sin embargo, ninguna, en forma individual, sustenta todas y cada una de las anomalías observadas, por lo que se ha considerado una entidad multifactorial. La identificación de anomalías (pre- y posnatalmente) sugestivas de secuencia de bandas amnióticas permite el abordaje diagnóstico para efectuar intervenciones terapéuticas oportunas que posibiliten la liberación de bandas amnióticas mediante fetoscopia con recuperación de la perfusión de la porción distal de la extremidad involucrada o bien la reparación quirúrgica posnatal y para otorgar asesoramiento genético. Este artículo ofrece una actualización sobre aspectos epidemiológicos, teorías etiológicas, factores de riesgo, características clínicas, diagnóstico (que incluye el diagnóstico prenatal), asesoramiento genético, abordaje terapéutico y pronóstico de esta entidad.

The prevalence of amnion rupture sequence, limb body wall defects and body wall defects in Alberta 1980-2012 with a review of risk factors and familial cases.

Prevalence rates of amnion rupture sequence, limb body wall defect, and body wall defects vary widely. Comparisons are difficult due to small case numbers and the lack of agreement of definition, classification, and pathogenesis. This study reports the prevalence of cases classified in five distinct categories. The Alberta Congenital Anomalies Surveillance System data on live births, stillbirths, and terminations of pregnancy (<20 weeks gestation) occurring between 1980 through 2012 with the ICD-10 Royal College of Paediatrics and Child Health Adaptation codes used for congenital constriction bands (Q79.80) and body wall complex (Q89.7) were reviewed. During the 33-year-study period, there were 153 eligible cases ascertained from 1,411,652 live births and stillbirths, giving a prevalence of 1.08/10,000 total births. There were more males (52%) than females (45%) and 3% were of unknown sex. The average maternal age, birth weight, and gestation was 27 years, 2,701 g, and 35 weeks, respectively. Limb deficiencies occurred in 78% of cases. Amniotic bands with limb deficiency was the most common phenotype (48%). Digital limb deficiency was the most frequent type (56%); however, cases with body wall defects had more severe types of limb deficiencies. The upper limbs only were affected more times (44%), and there was no side preference. Most cases are sporadic but a number of familial occurrences have been reported although some have insufficient documentation and others misdiagnosed. A review of putative risk factors gives conflicting results. © 2016 Wiley Periodicals, Inc.

Congenital constriction band syndrome with limb defects.

BACKGROUND: The purpose of this study was to clarify the spectrum of congenital constriction band syndrome (CBS) and associated anomalies and mortality in Finland. METHODS: Register-based data were analyzed for children with congenital constriction bands in upper and lower extremities as a part of an ongoing study on 419 upper limb defects and 171 lower limb defects occurring among 753,342 births in Finland during 1993 to 2005. RESULTS: A total of 71 cases with limb CBS were identified during the 13-year study period. The birth prevalence was 0.9 per 10 000 births (1:10 600). Infant mortality was 4.6% (3/65) and perinatal mortality 12.7% (9/71). In 35 cases (49%) only upper limbs were affected and in 13 cases (18%) there were constriction defects only in lower limbs. In 23 cases (32%) both upper and lower limbs were involved. None of the cases associated with a known syndrome. However, in 21 cases (30%) the child had other anomalies associated with constriction rings: pes equinovarus in 8/21, cleft palate in 5/21, congenital heart defect in 6/21, and other anomalies in 14/21. Eighteen (25%) had low birth weight, 22 (31%) were born preterm, and 8 children (11%) were small for gestational age. Children with associated anomalies showed higher mortality, shorter duration of gestation, and lower birth weight. CONCLUSIONS: CBS is rare and comprises approximately 12% of all congenital upper limb defects and 14% of lower limb defects. Other skeletal and nonskeletal anomalies are present in 30% of the affected children, suggesting a possible genetic etiology. More detailed characterization of the children with associated anomalies may shed light to the pathogenetic mechanisms of this syndrome. LEVEL OF EVIDENCE: Population-based register study/II.

Effect of an amniotic sheet on pregnancy outcomes.

OBJECTIVES: Our aim was to evaluate whether the presence of an amniotic sheet affects obstetric and neonatal outcomes. METHODS: All singleton pregnant women with and without a sonographic diagnosis of an amniotic sheet between the 16th and 24th weeks of pregnancy were retrospectively identified. Two women without an amniotic sheet were randomly selected from the similar stratified periods as a control group for each case. The demographic characteristics and obstetric and perinatal outcomes were compared between the groups. Multivariable logistic regression was also performed for potential confounding factors. In addition, the subsequent pregnancies of 12 women with an amniotic sheet were followed during the antenatal and postnatal periods. RESULTS: The prevalence of an amniotic sheet was 1.13%. The risk factors for an amniotic sheet were primiparity, previous normal vaginal delivery, previous dilation and curettage, and previous abortions. When the groups were compared in terms of maternal and neonatal outcomes, the rates of a nuchal cord at birth, breech birth, birth weight of less than 2500 g, preterm delivery (<37 weeks), and neonatal intensive care unit admission were higher in the amniotic sheet group than the control group. There were 2 intrauterine deaths in the amniotic sheet group. In addition, an amniotic sheet was not observed again in any of the subsequent pregnancies of the 12 cases from the amniotic sheet group, and these pregnancies eventuated uneventfully. CONCLUSIONS: An amniotic sheet is associated with an increase in poor obstetric outcomes. Therefore, close monitoring of pregnancies after diagnosis is required.

Associated malformations among infants with anophthalmia and microphthalmia.

BACKGROUND: Infants with anophthalmia and microphthalmia frequently have other associated congenital anomalies. The reported frequency and types of associated malformations vary among different studies. METHODS: The purpose of this investigation was to assess the frequency and types of associated malformations among infants with anophthalmia and microphthalmia in a geographically well defined population from 1979 to 2004 of 346,831 consecutive births. RESULTS: Of the 87 infants with anophthalmia and microphthalmia born during this period (prevalence at birth, 2.5 per 10,000), 90% had associated malformations. Infants with associated malformation were divided into recognizable conditions (22 infants [25%] with chromosomal and 15 infants [17%] with nonchromosomal conditions), and nonrecognizable conditions (41 infants [47%] with multiple malformations). Trisomies 13 and 18 were the most frequent chromosomal abnormalities. Amniotic bands sequence, CHARGE syndrome, Meckel-Gruber syndrome, and VACTERL association were most often present in recognizable nonchromosomal conditions. Malformations in the musculoskeletal, cardiovascular, and central nervous systems were the most common other anomalies in infants with multiple malformations and nonrecognizable conditions. CONCLUSIONS: The frequency of associated malformations in infants with anophthalmia or microphthalmia emphasizes the need for a thorough investigation of these infants. Routine screening for other malformations-especially musculoskeletal, cardiac, and central nervous system anomalies-may need to be considered in infants with anophthalmia or microphthalmia, and referral of these infants for genetics evaluation and counseling seems warranted.

Incidence of complications in twin-twin transfusion syndrome after selective fetoscopic laser photocoagulation: a single-center experience.

OBJECTIVE: The purpose of this study was to evaluate the incidence of complications after selective fetoscopic laser photocoagulation for twin-twin transfusion syndrome (TTTS). STUDY DESIGN: One hundred fifty-two cases of TTTS were treated with selective fetoscopic laser photocoagulation from 2005-2008. Complications were TTTS recurrence, amniotic band syndrome, iatrogenic monoamnionicity, and twin anemia-polycythemia sequence. Data were placed in the following categories: no complications; early complications < or =7 days; late complications >7 days; both early and late complications. RESULTS: The incidence of early, late, and both early and late complications was 31%, 39%, and 10%. Complications included 2 cases (1.3%) of monoamnionicity, 3 cases (2.0%) of recurrent TTTS, 3 cases (2.0%) of twin anemia-polycythemia sequence, and 5 cases (3.3%) of amniotic band syndrome. Cases with TTTS with early complications had a lower number of superficial arteriovenous vascular anastomoses and 1 or both fetus survival (70.2% vs 96.7%; P < .001), compared with no complications. Fetal survival was 238 of 307 cases (77.5%), with 1 or both twins surviving in 134 of 152 (88%) of pregnancies. CONCLUSION: The incidence of early, late, and both early and late complications was 31%, 39%, and 10%, respectively. Close postoperative surveillance is important.

Maternal vasoactive exposures, amniotic bands, and terminal transverse limb defects.

BACKGROUND: Limb reduction deficiencies that are accompanied by amniotic bands (AB-Ls) and terminal transverse limb deficiencies (TLDs) have each been attributed to vascular disruption; for the former, however, it is not clear if amniotic bands are the primary cause of or are secondary to vascular disruption. If amniotic bands are secondary to vascular disruption, then a shared pathogenesis for each case group might be exhibited by similar risk factors. METHODS: We evaluated maternal age, education, race/ethnicity, parity, pregnancy wantedness, and vasoactive exposures among 139 AB-L and 373 TLD cases, using interview data collected from mothers in 10 states by the National Birth Defects Prevention Study. Vasoactive exposures included maternal cigarette smoking and use of decongestants, nonsteroid anti-inflammatory drugs, and antihypertensive drugs in the periconceptional period. RESULTS: Increased risk estimates were observed for Black mothers (OR 2.5; 95% CI: 1.5-4.1) and nulliparous mothers (2.1; 1.4-3.0) in relation to AB-L, while neither was associated with TLD. Hispanic women (1.4; 1.0-1.9) and those not wanting the pregnancy (1.5; 1.1-2.1) had increased risks of TLD, but not AB-L. Maternal cigarette smoking and aspirin use each increased the risk of AB-L, but not TLD; while decongestants and possibly antihypertensive medications increased the risk of TLD, but not AB-L. CONCLUSIONS: The lack of consistent findings for the two case groups suggests that AB-L and TLD may be distinct entities. The inconsistencies also suggest that these vasoactive exposures may not be markers for vascular disruption or that vascular disruption may not play a major role in the pathogenesis of these two types of limb deficiencies.

Syndromes, disorders and maternal risk factors associated with neural tube defects (III).

Fetuses with neural tube defects (NTDs) may be associated with syndromes, disorders, and maternal and fetal risk factors. This article provides a comprehensive review of syndromes, disorders, and maternal and fetal risk factors associated with NTDs, such as omphalocele, OEIS (omphalocele-exstrophy-imperforate anus-spinal defects) complex, pentalogy of Cantrell, amniotic band sequence, limb-body wall complex, Meckel syndrome, Joubert syndrome, skeletal dysplasia, diabetic embryopathy, and single nucleotide polymorphisms in genes of glucose metabolism. NTDs associated with syndromes, disorders, and maternal and fetal risk factors are a rare but important cause of NTDs. The recurrence risk and the preventive effect of maternal folic acid intake in NTDs associated with syndromes, disorders and maternal risk factors may be different from those of nonsyndromic multifactorial NTDs. Perinatal identification of NTDs should alert the clinician to the syndromes, disorders, and maternal and fetal risk factors associated with NTDs, and prompt a thorough etiologic investigation and genetic counseling.

A new technique for correction of congenital constriction rings.

BACKGROUND: Congenital constriction ring (CCR) is among the most common congenital anomaly of the extremities. However, few techniques have been described for correction of this anomaly, and none of these techniques could provide a complete elimination of the deformity. Therefore, new surgical techniques are needed for correction of this challenging deformity. PURPOSE: Here, a new technique, namely, Mutaf procedure, for the correction of congenital constriction rings is described. MATERIAL AND METHOD: In this technique, following excision of the fibrotic constriction ring, the groove is filled with the turnover dermofat flaps elevated from both sides of the ring in an alternating pattern. Then skin closure is done with rectangular-plasty technique. Over 8 years, this new technique was used for correction of severe CCRs of the lower extremities in 7 patients aged 1-7 years. RESULTS: In all patients, a normal extremity contour was obtained, with complete elimination of the sandglass deformity caused by the constriction ring. A mean follow-up of 3 years revealed a normal growth of the operated extremity in all patients. The scars were found to be esthetically acceptable. No further surgery was required. CONCLUSIONS: Filling the circular groove caused by the constriction ring with dermofat flaps, this new technique eliminates the soft tissue deficiency and provides a normal extremity contour. Moreover, since rectangular-plasty allows replacing the major limbs of the incisional scars within the relaxed skin tension lines, it provides a better scar in comparison with old Z-plasty techniques.

Síndrome de brida amniótica y complejo "limb-body-wall": a propósito de un caso clínico / Amniotic brida syndrome and limb-body-wall complex: reviewing a clinical case

Se presenta un caso de síndrome de Brida amniótica que es una malformación congénita caracterizada por la formación de bandas fibrosas derivadas del amnios y que comprimen y estrangulan partes fetales especialmente cráneoencefálicas y de las extremidades. La etiopatogenia es desconocida y se descarta la participación de factores genéticos. Las formas menores son susceptibles de fetocopia y compatibles con la sobrevida. Las formas severas son incompatibles con la vida.

Epidemiologic analysis of maternal factors and amniotic band defects.

BACKGROUND: The group of defects identified as amniotic bands includes amnion rupture sequence (ARS) and body wall complex (BWC). Little is known about risk factors for either ARS or BWC, except that maternal age has been shown to affect risk inversely. METHODS: The present analysis used data collected from 1976 to 1998 as part of an ongoing case control study of birth defects in the metropolitan areas of Boston, Philadelphia, and Toronto. There were 73 cases with ARS and 11 cases with BWC. ARS cases were further subdivided according to affected structures: there were 53 with only limbs affected (ARS-L) and 20 with nonlimb defects with or without limb defects (ARS-NL). The control group comprised 12,227 subjects with other major malformations. Mothers were interviewed within 6 months of delivery about demographic, reproductive, medical, and behavioral factors. RESULTS: Multivariate adjusted odds ratios for BWC were increased more than threefold for maternal age < 25 years and maternal education < 12 years, but neither estimate was statistically significant. Corresponding estimates for ARS-L and ARS-NL ranged from 13 to 1.5 and also were not statistically significant. Cases were less likely to be white non-Hispanic than controls and the odds ratio for ARS-NL excluded the null. The multivariate adjusted odds ratio (MVOR) for unplanned pregnancy and BWC was 1.9 (95% confidence interval, 0.5-6.7) compared to 1.2 and 1.0 for ARS-L and ARS-NL, respectively. Neither parity nor maternal smoking was associated with any case group. The MVORs for first trimester acetaminophen use in relation to ARS-L and ARS-NL risks were 2.1 (1.1-3.9) and 3.4 (1.1-10.3), respectively. Such use was less common among BWC cases (MVOR was 0.4; 0.1-1.4). CONCLUSIONS: Risk estimates tended to be similar for ARS-L and ARS-NL cases but different for BWC cases, suggesting different etiologies. These data suggest that young maternal age, low maternal education, unplanned pregnancy, and non-white/non-Hispanic race/ethnicity might increase the risk of BWC in offspring. Inceased risks for acetaminophen use should be interpreted with caution because they may be confounded by indication for use.

Clinical and epidemiological studies of amniotic deformity, adhesion, and mutilation (ADAM) sequence in a South American (ECLAMC) population.

Amniotic deformity, adhesion, and mutilation (ADAM) sequence is a heterogeneous condition, with a broad spectrum of anomalies, where intrinsic causes, as defect of germ plasm, vascular disruption, and disturbance of threshold boundaries of morphogens during early gastrulation, alternate with extrinsic causes as amniotic band rupture to explain the condition. This study aimed to identify which phenotypes could be considered as ADAM sequence, determine the prevalence rate, and disclose risk factors for this sequence. We identified 270 cases defined as having some skin evidence of constriction band, plus those having limb defects suggestive of ADAM sequence, among 3,020,896 live and stillborns in the years 1982 to 1998 in ECLAMC (Latin American Collaborative Study of Congenital Malformations). Half of the cases presented mutilation (reduction), and deformity (ring constriction) affecting distal parts of fingers or toes bilaterally, without associated defects. Acrania, cephalocele, typical or atypical facial clefts, eyelid coloboma, and celosomia were also observed being significantly associated with the skin lesion. One affected infant in every 11,200 births, was found with stable trends during the last 17 years. There was an excess of cases in populations living at high altitude, stillborns, and neonatal infant dead. Among ADAM cases there was an excess of mothers with a prenatal history of febrile acute illness, medication drug use, or vaginal bleeding during the first trimester of pregnancy. Higher than expected frequencies of first-born child, premature birth, low birth weight for gestational length, and non-cephalic fetal presentation were also found. The observed geographic difference in birth prevalence could be a useful indication to study specific genetic and environmental candidate factors to ADAM susceptibility.

Limb deficiencies in newborn infants.

OBJECTIVE: The prevalence rate of all types of limb reduction defects in general and those that potentially are caused by vascular disruption in particular is needed to provide a baseline for the evaluation of infants who are exposed in utero to teratogens that cause vascular disruption. The objective of this study was to determine this prevalence rate. METHODS: All infants with any limb deficiency among 161 252 liveborn and stillborn infants and elective terminations were identified in a hospital-based Active Malformations Surveillance Program in Boston in the years 1972 to 1974 and 1979 to 1994. An extensive search was made to identify infants who were missed by the Surveillance Program; an additional 8 infants (7.3% of total) were identified. The limb reduction defects were classified in 3 ways: 1) by the anatomic location of the defect, that is longitudinal, terminal, intercalary, etc; 2) for infants with absence/hypoplasia of fingers or toes, a tabulation of which digit or digits were affected; and 3) by apparent cause. RESULTS: The prevalence rate for all types of limb deficiency was 0.69/1000. The apparent causes included single mutant genes, familial occurrence, and known syndromes (24%); chromosome abnormalities (6%); teratogens (4%); vascular disruption (35%); and unknown cause (32%). CONCLUSIONS: A hospital-based surveillance program can be used to establish the prevalence of limb reduction defects, if ascertainment is extended to include elective terminations for fetal abnormalities. An apparent cause can be established for most limb defects when the clinical findings are used rather than reliance only on the International Classification of Diseases, Ninth Revision, codes of the discharge diagnoses. The prevalence rate of limb reduction defects as a result of presumed vascular disruption was 0.22/1000.

Atypical presentation of amniotic band sequence.

Amniotic Band Sequence (ABS) is a disruption sequence that results in a variable group of abnormalities secondary to the disruption process and subsequent deformations. The incidence of ABS ranges from 1:1,200 to 1:15,000 live-born, and is even higher in still-born [Froster and Baird, 1993: Am J Med Genet 46:497-500]. The pathophysiology of ABS remains controversial, but a close look to critical periods of embryogenesis and/or organogenesis has helped in understanding pathogenetic mechanisms leading to the ABS disruption. The abnormalities are typically limited to external structures; however, associated internal malformations as seen in the case reported here may occur [Hunter and Carpenter, 1986: Am J Med Genet 24:691-700]. The prognosis depends on the severity of the abnormalities and the involvement of internal organs [Froster and Baird; 1993: Am J Med Genet 46:497-500; Levy, 1998: Ped Rev 19:249].