Influence of anaesthetic agent on limb abnormalities observed following amniotic sac puncture

In all of our previous studies into the effect of amniotic sac puncture (ASP) carried out on day 13 of pregnancy in mice, we have used intraperitoneal Avertin (tribromoethanol) as the general anaesthetic. In the present study, we used an inhalational anaesthetic (a mixture of halothane, oxygen and nitrous oxide in a ratio of 2:3:3). The principal difference between these two regimens is that even under optimal post-operative conditions when Avertin is used it can take between 45 and 90 min before complete recovery is achieved; when the inhalational anaesthetic is used, complete recovery is usually achieved within about 3-5 min. Because the experimental conditions were otherwise identical, this allowed the influence of the anaesthetic employed during ASP and the incidence of abnormalities induced on survival rate to day 19 of pregnancy to be studied. The survival rate was slightly higher when the inhalational anaesthetic was used, as was the incidence of limb abnormalities, although the overall incidence of gross abnormalities involving the palate, limbs and tail was not significantly different. The most marked difference, however, was in the incidence of syndactyly, which was significantly lower when the inhalational compared to the intraperitoneal anaesthetic was used: 26.6% v. 70.2% of the abnormal limbs analysed. A possible hypothesis is presented to explain this difference.     

Limb‐body wall defect: Experience of a reference service of fetal medicine from Southern Brazil

Background: Limb‐body wall defect is a rare condition characterized by a combination of large and complex defects of the ventral thorax and abdominal wall with craniofacial and limb anomalies. Methods: The aim of this study was to describe the experience of our fetal medicine service, a reference from Southern Brazil, with prenatally diagnosed patients with a limb‐body wall defect in a 3 years period. Only patients who fulfilled the criteria suggested by Hunter et al. (2011) were included in the study. Clinical data and results of radiological and cytogenetic evaluation were collected from their medical records. Results: Our sample was composed of 8 patients. Many of their mothers were younger than 25 years (50%) and in their first pregnancy (62.5%). It is noteworthy that one patient was referred due to suspected anencephaly and another due to a twin pregnancy with an embryonic sac. Craniofacial defects were verified in three patients (37.5%), thoracic/abdominal abnormalities in 6 (75%) and limb defects in eight (100%). Congenital heart defects were observed in five patients (62.5%). One of them presented a previously undescribed complex heart defect. Conclusion: The results disclosed that complementary exams, such as MRI and echocardiography, are important to better define the observed defects. Some of them, such as congenital heart defects, may be more common than previously reported. This definition is essential for the proper management of the pregnancy and genetic counseling of the family. The birth of these children must be planned with caution and for the prognosis a long survival possibility, despite unlikely and rare, must be considered. Birth Defects Research (Part A) 100:739–749, 2014. © 2014 Wiley Periodicals, Inc.     

Ectopia cordis thoracalis with craniofacial defects resulting from early amnion rupture

A 33-week-gestation fetus was evaluated as having ectopia cordis thoracalis, midline sternal cleft, frontonasal dysgenesis, a midfacial cleft, and amniotic bands. Fibrous bands were attached to the apex of the heart, face, and the brain. There were no associated limb defects or scoliosis. The findings in this fetus and those in the literature suggest that acute amnion rupture in the third week of gestation may be the cause of these defects. Mechanical teratogenesis by tissue bands adherent to the heart may lead to ectopia cordis. The changes seen in the thorax, face, and brain suggest pressure necrosis, incomplete morphogenesis, tearing and tethering by amnion, and compression as a cause for these defects. A spectrum of defects is found following amnion rupture with the abnormalities being dependent upon the timing of the event. Ectopia cordis with amniotic bands appears to have an etiology distinct from isolated ectopia cordis. This suggests several different etiologies for ectopia cordis.     

Craniofacial anomalies of the amniotic band syndrome in serial clinical cases

Amniotic band syndrome has been proposed as a sequela of intrauterine rupture of the amnion, resulting in oligohydramnios and passage of the fetus into the chorionic cavity. Amnion disruption with loss of amniotic fluid, causing fetal compression and localized fetal ischemia, possibly results in a pathogenic mechanism of extremely variable malformations. The prominence of the nasal processes and the adjacent stomodeal orifice facilitates free band attachment and adherence, resulting in a spectrum of similarly oriented facial defects. The authors present six consecutive cases of amniotic band syndrome with cleft lip and palate (facial cleft 3, 5, 7, and 10, isolated or combined) that were associated with other craniofacial anomalies, such as craniosynostosis and hypertelorbitism. They also present limb malformations and discuss the proposed pathogenesis and the surgical challenges in functional and aesthetic restoration.     

Caffeine effects on cyclic AMP levels in the mouse embryonic limb and palate in vitro

Caffeine is a teratogen that causes limb and palate malformations in rodents. Since the ability to raise cyclic nucleotide levels is a known biological action of caffeine, cyclic AMP levels were measured in CD-1 mouse embryonic forelimb from whole embryo culture and embryonic limb and palate cells grown in primary culture following treatment with various concentrations of caffeine (0, 1, 3, or 10 mM). In forelimb buds from whole embryo culture, a dose-dependent response was observed. Caffeine at 1 mM concentration stimulated cyclic AMP levels to 151% of control value at 60 min. Even greater stimulation of cyclic AMP occurred at higher caffeine concentrations. A dose-dependent response was seen in both limb and palate cell culture. In limb cell culture, all caffeine concentrations significantly stimulated cyclic AMP after 10 min compared to control. In palate cell culture, there was a twofold increase in cyclic AMP at the 1-mM caffeine concentration. At higher caffeine concentrations, cyclic AMP was significantly increased after 60 min. In addition, stimulation of cyclic AMP in cultured limb and palate cells by isoproterenol, a beta-adrenergic agonist, was used as a positive control. Isoproterenol stimulated a 2.5-fold greater response in the palate cells than in the limb bud cells at isoproterenol levels of 10(-5) or 10(-4) M. The increase of cyclic AMP may be influential in the process of abnormal limb or palate development.     

Amniotic fluid induces rapid epithelialization in the experimentally ruptured fetal mouse palate--implications for fetal wound healing

Cleft of the secondary palate is one of the most common congenital birth defects in humans. The primary cause of cleft palate formation is a failure of fusion of bilateral palatal shelves, but rupture of the once fused palate has also been suggested to take place in utero. The possibility of post-fusion rupture of the palate in humans has hardly been accepted, mainly because in all the cleft palate cases, the cleft palatal edge is always covered with intact epithelium. To verify whether the intrauterine environment of the fetus plays roles in wound healing when the once fused palate is torn apart, we artificially tore apart fetal mouse palates after fusion and cultivated them in culture medium with or without mouse or human amniotic fluid. We thereby found that the wounded palatal edge became completely covered with flattened epithelium after 36 hours in culture with amniotic fluid, but not in culture without amniotic fluid. Using histological and scanning electron microscopic analyses of the healing process, it was revealed that the epithelium covering the wound was almost exclusively derived from the adjacent nasal epithelium, but not from the oral epithelium. Such actions of amniotic fluid on the fetal wound were never simulated by exogenous epidermal growth factor (EGF), albumin, or both. In addition, the rapid epithelialization induced by amniotic fluid was not prevented by either PD168393 (an inhibitor of the EGF receptor-specific tyrosine kinase) or SB431542 (a specific inhibitor of TGFbeta receptor type I/ALK5). The present study provides new insights into the unique biological actions of amniotic fluid in the repair of injured fetal palate.     

Effects of isotretinoin (13-cis-retinoic acid) on the development of mouse limbs in vivo and in vitro.

Isotretinoin (13-cis-RA) is known to be teratogenic in humans and laboratory animals. The relatively low potency of 13-cis-RA in NRMI mice in comparison to the all-trans isomer has been proposed to be due to minimal transfer across the placenta (Creech-Kraft et al., '87). To further delineate the teratogenic potential of 13-cis-RA, a dose-response, temporal study was conducted in vivo and in vitro using submerged limb culture and image analysis evaluation of development. Dose-dependent embryotoxicity was produced by treatment on GD 7, while later treatments produced inconsistent effects on resorption rate and fetal weight. Treatment on either GD 7 or GD 8 produced a number of malformations in dose-dependent manner. Most common were tail and cleft palate defects, which were produced by 13-cis-RA on each of the days tested (GD 7-GD 11), with peak malformations occurring on GD 9 and GD 10 for tail and cleft palate, respectively. Most limb defects were produced after GD 10 and GD 11 exposure. The observed frequency of defects confirmed that in ICR mice 13-cis-RA is about 10-fold less potent than all-trans-RA as a limb teratogen (Kwasigroch and Kochhar, '80; Kochhar and Penner, '87). Effects observed via image analysis following maintenance of limbs in serum-free culture medium were dose dependent. Low dose treatment produced occasional polydactyly. The intermediate dose caused somewhat variable region-dependent increases in cartilaginous bone anlagen area. The high dose of 13-cis-RA produced irregular limb outlines, a reduction in bone anlagen area, and an inhibition of alcian blue staining of cartilage without affecting morphogenesis of bone anlagen. These results confirm that, when the effects of the administered doses are evaluated, 13-cis-RA is a much less potent teratogen in comparison to the all-trans isomer. More importantly, the results show that retinoids can enhance (at low and intermediate doses), depress (at high doses), or eliminate (high dose) chondrogenenic expression during limb morphogenesis in vitro. This indicates that retinoids such as 13-cis-RA can manipulate events in development in a variety of ways (i.e., produce malformations, interfere with chondrogenic expression without affecting morphogenesis, and stimulate growth) in a dose- and time-dependent manner. Although the ability of RA to act as a true morphogen has recently been questioned (Wanek et al., '91; Noji et al., '91), the results presented here support the position that RA can modulate the development of the limb (and probably other organ systems) in several vertebrate species.     

Maternal panic disorder and congenital abnormalities: a population-based case-control study

BACKGROUND: Maternal panic disorder in pregnancy is the most common manifestation of anxiety disorders in Hungary. The association between panic disorder during pregnancy and structural birth defects, i.e., congenital abnormalities, was studied. METHODS: The prevalence of maternal panic disorder in cases with different congenital abnormalities was compared to that of matched controls in the population-based Hungarian Case-Control Surveillance System of Congenital Abnormalities. RESULTS: Of 22,843 cases with congenital abnormalities, 210 (0.9%) had mothers with panic disorder during pregnancy compared to 187 (0.5%) of 38,151 controls (adjusted prevalence odds ratio [POR] 1.6; 95% CI, 1.3-2.0). Specific groups of congenital abnormalities were also assessed versus controls. Cases with isolated cleft lip with or without cleft palate (CL/P) (adjusted POR, 3.4; 95% CI, 1.3-9.0) and multiple congenital abnormalities (adjusted POR, 3.0; 95% CI, 1.2-7.2) were more likely to have had mothers with panic disorder during the study pregnancy. Notably, among mothers with panic disorders, the associations were found only in offspring of untreated mothers. CONCLUSIONS: A higher rate of isolated CL/P and multiple congenital abnormalities may be caused by the direct biological effect of panic disorder or by the interaction of maternal panic disorder and lifestyle factors. Antipanic drug treatment seems to have a protective effect for isolated CL/P and multiple congenital abnormalities. Birth Defects Research (Part A), 2006.     

The concurrence of ring constrictions in Adams-Oliver syndrome: additional evidence for vascular disruption as common pathogenetic mechanism.

We report on a girl with congenital scalp and acral reduction limb defects, consistent with the diagnosis of Adams-Oliver syndrome. The presence of constriction rings makes the limb anomalies in this case similar to those seen in the amniotic band disruption sequence. Vascular disruption--with or without secondary amniotic rupture--may be responsible for the observed anomalies. Therefore we believe that the present observation adds further evidence for the hypothesis that the Adams-Oliver syndrome is a vascular disruption sequence.     

Steroid contraceptive use and pregnancy outcome

Contraceptive use in relation to pregnancy outcome was studied in 8,816 births in Chiang Mai, northern Thailand, by examination of newborn infants and interviews with their mothers. Four thousand twenty-three women used no contraception before the index pregnancy, 1,229 used the injectable contraceptive Depo Provera (DMPA), and 3,038 used oral contraceptives prior to or during pregnancy. No differences were observed between these groups with respect to still births, multiple pregnancies, and birthweight. Women who used oral contraceptives had unexpectedly low rates of major defects and may have been affected by self-selection bias, whereas the noncontraceptors had rates similar to other populations. There was a significantly increased association of polysyndactyly among infants of DMPA users relative to the other groups, which was most pronounced in offspring of women under age 30 years, and persisted after exclusion of subjects with a family history or infants with multiple abnormalities. However, in five out of the ten polysyndactyly cases, the last injection of DMPA occurred more than 9 months before conception, and only three cases had definite gestational exposure. The association of chromosomal anomalies was also significantly increased in infants of mothers who used DMPA. The unrelated nature of these defects, the lack of confirmation from other studies, the distant preconceptional exposure to DMPA in many cases, and chance effects due to multiple statistical comparisons make a causal association unlikely. Other birth defects that had been previously reported in some publications to be associated with progestational steroid exposure, such as neural tube defects, heart malformations, and limb reduction defects, were not found in this study.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preventive effect of piperonyl butoxide on cyclophosphamide-induced teratogenesis in rats

BACKGROUND: Cyclophosphamide induces fetal defects through metabolic activation by cytochrome P-450 monooxygenases (CYP). The effects of piperonyl butoxide (PBO), a CYP inhibitor, on the fetal development and external, visceral, and skeletal abnormalities induced by cyclophosphamide were investigated in rats. METHODS: Pregnant rats were daily administered PBO (400 mg/kg) by gavage for 7 days (the 6th to 12th day of gestation), and intraperitoneally administered with cyclophosphamide (12 mg/kg) 4 h after the final treatment. On the 20th day of gestation, maternal and fetal abnormalities were determined by Cesarean section. RESULTS: Cyclophosphamide reduced fetal body weights by 30–40% without increasing resorption or death. In addition, it induced malformations in live fetuses: 100, 98, and 98.2% of the external (head and limb defects), visceral (cerebroventricular dilatation, cleft palate, and renal pelvic/ureteric dilatation), and skeletal (acrania, vertebral/costal malformations, and delayed ossification) abnormalities, respectively. The pre-treatment of PBO greatly decreased mRNA expression and activity of hepatic CYP2B, which metabolizes cyclophosphamide into teratogenic acrolein and cytotoxic phosphoramide mustard. Moreover, PBO remarkably attenuated cyclophosphamide-induced body weight loss and abnormalities of fetuses; score 3.57 versus 1.87 for exencephaly, 75.5% versus 42.5% for limb defects, 65.3% versus 22% for cerebroventricular dilatation, 59.2% versus 5.1% for cleft palate, score 1.28 versus 0.93 for renal pelvic/ureteric dilatation, 71.9–82.5% versus 23–45.9% for vertebral/costal malformations, and 84.2% versus 57.4% for delayed ossification in cyclophosphamide alone and PBO co-administration groups. CONCLUSIONS: These results suggest that repeated treatment with PBO may improve cyclophosphamide-induced body weight loss and malformations of fetuses by down-regulating CYP2B. Birth Defects Res (Part B) 86:402–408, 2009. © 2009 Wiley-Liss, Inc.     

Limb reduction defects in humans associated with prenatal isotretinoin exposure.

Retinoic acid has long been used to induce limb reductions defects in experimental animal studies. No limb malformations, however, have been reported among malformed retinoic acid-exposed human fetuses from case reports or epidemiologic studies. We report a child and a fetus with limb reduction malformations following maternal use of isotretinoin (13-cis-retinoic acid) during the first trimester of pregnancy. The child had a unilaterally absent clavicle and nearly absent scapula, with a short humerus and short, synostotic forearm bones. He also had ventriculomegaly and developmental delay, minor dysmorphic facial features, and a short sternum with a sterno-umbilical raphe. The fetus had a unilaterally absent thumb with normal proximal bony structures. Other findings included hydrocephalus, craniofacial anomalies, thymic agenesis, supracristal ventricular septal defect, single umbilical artery, anal and vaginal atresia, and urethral agenesis with dysplastic, multicystic kidneys. Although the limb malformations were quite dissimilar, a number of anomalies that are frequently found among isotretinoin-exposed fetuses/infants were present in both cases. This increases the probability that retinoic acid caused these limb defects, but a causal association cannot be conclusively drawn on the basis of these two retrospective case reports.     

Frequency of congenital defects and dominant lethals in the offspring of male mice treated with methylnitrosourea

ICR strain male mice injected intraperitoneally with daily doses of MNU (5–25 mg/kg) for 5 days and mated to untreated virgin females of the same strain on days 1–7, 8–14, 15–21 and 64–80 after the last dose. Copulations during these periods involve, respectively, spermatozoa, late spermatids, early spermatids, and spermatogonial stem cells at the time of the last treatment. The uterine contents were examined on day 18 of pregnancy for post-implantation losses (dominant lethality). Fetuses were examined for exteranal and skeletal abnormalities. In contrast to the results reproted for specific-locus mutations, MNU treatment of either postmeiotic cells or spermatogonial stem cells caused dose-dependent significant increases in the incidence of congenital defects and of dominant lethals over the control levels. The relative sensitivity of germ cells sampled on days 1–7, 8–21 and 64–80 to MNU-induced congenital defects was 1:1.6:2. For the induction of dominant lethals, the sensitivity ratio was 1:1.8:0.5. It is proposed that congenital defects in the offspring of mice following paternal treatment with MNU may represent mostly chromasomal rather than genic changes. Cleft palate was the most frequent of the external abnormalities, which were significantly induced in every treatment series; fused ribs were the most frequent of the skeletal abnormalities, which were significatly induced in the treatment series for spermatogonial stem cells.     

Medications used to treat nausea and vomiting of pregnancy and the risk of selected birth defects

BACKGROUND Nausea and vomiting of pregnancy (NVP) occurs in up to 80% of pregnant women, but its association with birth outcomes is not clear. Several medications are used for the treatment of NVP; however, data are limited on their possible associations with birth defects. METHODS Using data from the National Birth Defects Prevention Study (NBDPS)—a multi‐site, population‐based, case‐control study—we examined whether NVP or its treatment was associated with the most common noncardiac defects in the NBDPS (nonsyndromic cleft lip with or without cleft palate [CL/P], cleft palate alone [CP], neural tube defects, and hypospadias) compared with randomly selected nonmalformed live births. RESULTS Among the 4524 cases and 5859 controls included in this study, 67.1% reported first‐trimester NVP, and 15.4% of them reported using at least one agent for NVP. Nausea and vomiting of pregnancy was not associated with CP or neural tube defects, but modest risk reductions were observed for CL/P (adjusted odds ratio [aOR] = 0.87; 95% confidence interval [CI], 0.77–0.98) and hypospadias (aOR = 0.84; 95% CI, 0.72–0.98). Regarding treatments for NVP in the first trimester, the following adjusted associations were observed with an increased risk: proton pump inhibitors and hypospadias (aOR = 4.36; 95% CI, 1.21–15.81), steroids and hypospadias (aOR = 2.87; 95% CI, 1.03–7.97), and ondansetron and CP (aOR = 2.37; 95% CI, 1.18–4.76), whereas antacids were associated with a reduced risk for CL/P (aOR = 0.58; 95% CI, 0.38–0.89). CONCLUSIONS NVP was not observed to be associated with an increased risk of birth defects; however, possible risks related to three treatments (i.e., proton pump inhibitors, steroids and ondansetron), which could be chance findings, warrant further investigation. Birth Defects Research (Part A) 2012. © 2011 Wiley Periodicals, Inc.     

A familial tetraphocomelia syndrome involving limb deformities,cleft lip,cleft palate,and associated anomalies —A new syndrome

Summary This paper reports a rare malformation syndrome which is observed in two sibs (brother and sister) of a family. It consists of nearly symmetric reductive defects of the limbs, flexon contractures of various joints, cleft lip and cleft palate, multiple minor abnormalities including capillary hemangioma of the forehead, hypoplastic cartilages of ears and nose, micrognathia, intrauterine growth retardation, and possibly mental retardation. Chromosomes of both parents and propositi are normal. Genetic data suggest autosomal recessive inheritance.     

Teratogen update: methotrexate

Methotrexate and aminopterin are folic acid antagonists that inhibit dihydrofolate reductase, resulting in a block in the synthesis of thymidine and inhibition of DNA synthesis. Methotrexate has been used for the treatment of malignancy, rheumatic disorders, and psoriasis and termination of intrauterine pregnancy. Recently, methotrexate has become a standard treatment for ectopic pregnancy. The misdiagnosis of an intrauterine pregnancy as an ectopic pregnancy can result in exposure of a continuing pregnancy to dose levels of methotrexate of 50 mg/m(2) (maternal body surface area). Experimental animal studies have associated methotrexate therapy with embryo death in mice, rats, rabbits, and monkeys. Structural malformations have been most consistently produced in rabbits at a maternal dose level of 19.2 mg/kg. Abnormalities in rabbits include hydrocephalus, microphthalmia, cleft lip and palate, micrognathia, dysplastic sacral and caudal vertebrate, phocomelia, hemimelia, syndactyly, and ectrodactyly. Based on human case reports of methotrexate exposure during pregnancy, a methotrexate embryopathy has been described that includes growth deficiency, microcephaly, hypoplasia of skull bones, wide fontanels, coronal or lambdoidal craniosynostosis, upswept frontal scalp hair, broad nasal bridge, shallow supraorbital ridges, prominent eyes, low-set ears, maxillary hypoplasia, epicanthal folds, short limbs, talipes, hypodactyly, and syndactyly. This syndrome may be associated with exposures between 6 and 8 weeks after conception and dose levels of 10 mg/week or greater. More recent case reports of methotrexate exposure for the misdiagnosis of ectopic pregnancy involve treatment before 6 weeks after conception and have raised the suggestion of a distinct syndrome due to such early exposures. Tetralogy of Fallot and perhaps other neural crest cell-related abnormalities may be features of this early syndrome. A disproportionality analysis of methotrexate and aminopterin case reports and series provides support for pulmonary atresia, craniosynostosis, and limb deficiencies as reported more often than expected in methotrexate-exposed children. Denominator-based data will be welcome to better define elements of a methotrexate embryopathy and possibly to distinguish an early exposure syndrome from anomalies traditionally associated with methotrexate exposure.     

The effects of nitrous oxide on the developing hamster embryos

Pregnant hamsters were exposed to different concentrations of nitrous oxide during the period of organogenesis. Teratogenic effects were observed in a small but significant number of fetuses. Types of malformations included cleft palate, limb defects, gut herniation, and fetal edema. A dose-effect relationship was not observed. It is not clear from our observations whether the observed effect on the fetuses was due to the excess of nitrous oxide, hypoxia, or a combination of both. Comparison with published literature indicates that further studies on the effects of nitrous oxide in placental animals are needed.     

The effect of hypoxia in development

There is increasing evidence that the oxygen supply to the human embryo in the first trimester is tightly controlled, suggesting that too much oxygen may interfere with development. The use of hypoxia probes in mammalian embryos during the organogenic period indicates that the embryo is normally in a state of partial hypoxia, and this may be essential to control cardiovascular development, perhaps under the control of hypoxia-inducible factor (HIF). A consequence of this state of partial hypoxia is that disturbances in the oxygen supply can more easily lead to a damaging degree of hypoxia. Experimental mammalian embryos show a surprising degree of resilience to hypoxia, with many organogenic stage embryos able to survive 30-60 min of anoxia. However, in some embryos this degree of hypoxia causes abnormal development, particularly transverse limb reduction defects. These abnormalities are preceded by hemorrhage/edema and tissue necrosis. Other parts of the embryo are also susceptible to this hypoxia-induced damage and include the genital tubercle, the developing nose, the tail, and the central nervous system. Other frequently observed defects in animal models of prenatal hypoxia include cleft lip, maxillary hypoplasia, and heart defects. Animal studies indicate that hypoxic episodes in the first trimester of human pregnancy could occur by temporary constriction of the uterine arteries. This could be a consequence of exposure to cocaine, misoprostol, or severe shock, and there is evidence that these exposures have resulted in hypoxia-related malformations in the human. Exposure to drugs that block the potassium current (IKr) can cause severe slowing and arrhythmia of the mammalian embryonic heart and consequently hypoxia in the embryo. These drugs are highly teratogenic in experimental animals. There is evidence that drugs with IKr blockade as a side effect, for example phenytoin, may cause birth defects in the human by causing periods of embryonic hypoxia. The strongest evidence of hypoxia causing birth defects in the human comes from studies of fetuses lacking hemoglobin (Hb) F. These fetuses are thought to be hypoxic from about the middle of the first trimester and show a range of birth defects, particularly transverse limb reduction defects.     

Comparative study of clinical characteristics of amniotic rupture sequence with and without body wall defect: Further evidence for separation

BACKGROUND: Amniotic rupture sequence (ARS) is a disruption sequence presenting with fibrous bands, possibly emerging as a result of amniotic tear in the first trimester of gestation. Our comparative study aims to assess whether there is a difference in the clinical pattern of congenital limb and internal organ anomalies between ARS with body wall defect (ARS‐BWD) and ARS without BWD (ARS‐L). METHODS: Among 1,706,639 births recorded between 1998 and 2006, 50 infants with a diagnosis of ARS were reported to the Polish Registry of Congenital Malformations. The information on 3 infants was incomplete, thus only 47 cases were analyzed. These infants were classified into groups of ARS‐L (38 infants) and ARS‐BWD (9 infants). RESULTS: The ARS‐BWD cases were more frequently affected by various congenital defects (overall p < 0.0001), and in particular by urogenital malformations (p = 0.003). In both groups, limb reduction defects occurred in approximately 80% of cases; however, minor and distal limb defects (phalangeal or digital amputation, pseudosyndactyly, constriction rings) predominated in the ARS‐L group (p = 0.0008). The ARS‐L group also had a higher frequency of hand and upper limb involvement. CONCLUSIONS: This observation suggests that amniotic band adhesion in ARS‐L takes place at a later development stage. Although limited by a small sample size, our study contributes to the growing evidence that both ARS entities represent two nosologically distinct conditions. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.     

Prenatal repair of experimentally induced clefts in the secondary palate of the rat

A refined technique of amniotic sac puncturing at day 16.2 (i.e., 16 + 2/10 days) of gestation was employed in order to produce a series of total clefts and rare forms of partial clefts in Sprague-Dawley rat fetuses. From a total of 410 fetuses of a precise, individually determined age, 95 upper jaws were examined in the scanning electron microscope and, in part, in serial Epon sections. All fetal heads were examined macroscopically. Total clefts were found in 48.9% of a total of 184 viable rat fetuses examined at day 17.8 of smear age and in 21.8% of a total of 211 fetuses examined at day 19.3. Partial clefts were observed in 14.1% and 18.5% of fetuses at days 17.8 and 19.3 of smear age, respectively. At day 19.3, 16.1% of the viable fetuses showed a very inconspicuous, small abnormality (with residual clefting and incomplete fusion with the nasal septum) in the region of the palatine foraminae. Morphological observations suggested that under conditions of detained palatal closure (1) fusion of the soft palatal shelves commences independently from and prior to fusion of the hard palate, (2) delayed palatal shelf fusion proceeding in the anterior direction may occur with or without remaining sickle-shaped clefts in the anterior hard palate, and (3) in fetuses with small sickle-shaped clefts, fusion of the palatal shelves with the nasal septum does not occur. The present data imply that an almost total prenatal repair and delayed closure of the secondary palate may occur in rats that, at day 16.2 of multiple analysis age, most certainly had a total palatal cleft resulting from tongue resistance.