title: [Premature birth in patient with cervix incompetence and history of myasthenia gravis].
abstract: Cervical incompetence it's a dilatation of the cervix during the third trimester of pregnancy that ends with the interruption of it. The incidence in Chile is about 0.1-2% of the total pregnancies and it's one of the causes of preterm birth. A 34 years old pregnant patient. Timectomized at age 18 to treat her miastenia gravis, previously trated with medication, had 4 previous preterm labours all of them under 25 weeks and vaginal births. All fetuses died postpartum. A cerclage was made during the third, fourth and fifth pregnancies. She didn't present hypertension during the gestation and no cervical diameter under 15mm. Since the fourth gestation the following tests are taken: Antifosfolipidic antibodies, APTT,PT. All the results are either normal or negative. Microbial cultures were negative. No amniocentesis was made. A McDonald cervical cerclage was made during pregnancies number 3, 4 and 5 on the 16th week to delay the labor. Also oral micronized progesterone, on a 400mg/24 hours dosis, was administered to avoid preterm birth. On the 24th week the pharmacological treatment started including Intramuscular Betamethasone, 12 mg/24 hours (2 doses), to induce lung maturity on the fetus. It is thought that the administration of progesterone could have improved the situation of the patient, because it acts as a labour repressants. The use of cerclage could have helped, but the factors that may influence the effectiveness of this method are unknown. Perhaps there is some immunologic factor associated with the miastenia gravis that alters the normal course of pregnancy.
authors.affiliation: Universidad Católica de la Santísima Concepción, Chile. mefuentealba@medicina.ucsc.cl
authors.forename: Maximiliano
authors.initials: M
authors.lastname: Fuentealba
authors.forename: Miguel
authors.initials: M
authors.lastname: Troncoso
authors.forename: Joaquin
authors.initials: J
authors.lastname: Vallejos
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ponce
authors.forename: Nelson
authors.initials: N
authors.lastname: Villablanca
authors.forename: Pablo
authors.initials: P
authors.lastname: Melita
mesh_terms: D000328:Adult; D002584:Cervix Uteri; D005260:Female; D006801:Humans; D009157:Myasthenia Gravis / Q000150:complications*; D011247:Pregnancy; D047928:Premature Birth / Q000209:etiology*; D002581:Uterine Cervical Incompetence / Q000209:etiology*