misoprostol and Amniotic-Band-Syndrome

Amniotic band syndrome (ABS) is a fetal congenital malformation, affecting mainly the limbs, but also the craniofacial area and internal organs. Two mains pathogenic mechanisms are proposed in its genesis. Firstly the early amnion rupture (exogenous theory) leading to fibrous bands, which wrap up the fetal body; secondly, the endogenous theory privileges vascular origin, mesoblastic strings not being a causal agent. The authors believe that the second theory explain the occurrence of ABS. The outcome of the disease during pregnancy depends on the gravity of the malformations. Interruption of the pregnancy is usually proposed when diagnosis of severe craniofacial and visceral abnormalities is confirmed. Whereas minor limb defects can be repaired with postnatal surgery. In case of an isolated amniotic band with a constricted limb, in utero lysis of the band can be considered to avoid a natural amputation. In an African country, such treatment is not possible as far as the antenatal diagnosis.

Topics: Abortifacient Agents, Nonsteroidal; Abortion, Induced; Adult; Africa; Amniotic Band Syndrome; Delivery, Obstetric; Developing Countries; Female; Humans; Infant, Newborn; Lower Extremity Deformities, Congenital; Misoprostol; Pregnancy; Ultrasonography, Prenatal

Several malformations have been attributed to the process of vascular disruption. The central hypothesis for this etiology is that blood flow to a structure has been altered after that structure had formed normally. The decreased blood flow leads to hypoxia, endothelial cell damage, hemorrhage, tissue loss, and repair. After recovery, some structures are normal and others show either tissue loss or structural abnormalities, such as syndactyly and constriction rings.. The phenotypic features of the 7,020 infants with one or more malformations, who were born to women who had always planned to deliver at Brigham and Women's Hospital (BWH) between, 1972 and 2012, that is, maternal nontransfers, were reviewed. The phenotypes associated with vascular disruption, such as the amniotic band syndrome and terminal transverse limb defects (TTLD), were identified.. One hundred and five fetuses and infants had malformations attributed to the process of vascular disruption. Some specific causes of the amniotic band limb deformity were identified. TTLD with associated small digit-like nubbins occurred at three levels: proximal forearm, wrist, and metacarpal-phalangeal joint. Other causes included severe hemoglobinopathies and exposures to misoprostol and to prenatal procedures.. Malformations attributed to the process of vascular disruption were a distinctive entity, among the recognized etiologies. The timing of the causative event in the first trimester was established for infants with exposures to either the prostaglandin misoprostol or the prenatal diagnosis procedure chorionic villus sampling. One challenge is to identify the developmental steps in vascular disruption when no causative exposure can be identified.

Topics: Amniotic Band Syndrome; Cell Hypoxia; Female; Hemoglobinopathies; Humans; Hydranencephaly; Infant, Newborn; Limb Deformities, Congenital; Misoprostol; Poland Syndrome; Pregnancy; Prenatal Diagnosis; Regional Blood Flow; Vascular Malformations

Misoprostol is a synthetic prostaglandin analog administered vaginally to induce labor for intrauterine death or termination of pregnancy for congenital abnormalities. We encountered a case of misoprostol induction of labor at 14 weeks of gestation for fetal acrania associated with amniotic bands. Histology demonstrated abundant deposits of refractile material appearing to be of vegetable fiber origin on the maternal surface of the fetal membranes. Misoprostol tablet scrapings had a similar microscopic appearance. Ten additional placentas from cases of misoprostol induction of labor between 16 and 18 weeks of gestation were examined and half were found to contain such deposits. No deposits were seen in cases between 15 and 18 weeks of gestation where misoprostol was not used. We attribute the refractile material to a nonmedicinal ingredient, microcrystalline cellulose, in the misoprostol tablet preparation. This study demonstrates that vaginal administration of misoprostol tablets can be detected microscopically in at least half of cases and may have a florid appearance simulating a potential causative factor of fetal malformation. Despite the large amounts of microcrystalline cellulose and its apparent embedding in placental tissue, the misoprostol in our index case was unlikely to have caused the amniotic bands and the resulting cranial abnormality.

Topics: Abortifacient Agents, Nonsteroidal; Abortion, Induced; Administration, Intravaginal; Adult; Amniotic Band Syndrome; Cellulose; Excipients; Female; Fetus; Humans; Infant, Newborn; Misoprostol; Neural Tube Defects; Placenta; Pregnancy