[Prenatal diagnosis of skeletal dysplasia: case report of a fetus with multiple anomalies].

INTRODUCTION: Skeletal anomalies are in the group of anomalies most difficult to be diagnosed antenatally. But, because of high lethality and morbidity rate as well as high possibility to be found again in the next pregnancy, they need to be systematically and actively looked for during every scan.

CASE REPORT: A pregnant woman, aged 18, primigravida, was admitted to the Dept. of Obstetrics and Gynaecology because of polyhydramnios and suspected multiple fetal malformations. Fetal biparietal diameter and abdominal circumference were adequate for 33 weeks gestation, whereas all the long bones were short for the gestational age. A detailed ultrasound morphology check was impossible because of the excessive amount of amniotic fluid, but the skull, brain, lungs, spine and abdomen appeared normal. There was an impression of frontal bossing and left-sided cleft lip. A thoraco-abdominal disproportion was evident. All the extremities were short, feet were normal, and hands were not extended during the whole scan. The woman underwent an uneventful amino-drainage and three days after that she ruptured the membranes, giving birth to a live female, 2150 gr, 46 cm, Apgar score 6/7. The anomalies seen on ultrasound were confirmed after birth. After a series of dyspnea the neonate was transferred to the Dept. of Paediatrics where it underwent a series of further extensive diagnostic procedures and 37 days after birth it passed away. Postmortem examination led to the following diagnoses: Neonatus femininus eutrophicus temporis aetatis. Defectus partis memebranacei septi interventricularis. Ductus arteriosus Botalli persistence. Hypoplasia thymi. Cheliognathopalatoschisis. Low set ears. Extremitates breves. Atelectasis subtotalis pulmonis bilateralis. Foramen ovale apertum cum valvula competent. Oedema cerebri gradus maioris.

DISCUSSION: Majority of fetal skeletal malformations can be relatively easily visualised during ultrasound scans and hence ultrasound is the most sensitive way of prenatal diagnosis of these anomalies. Maternal habitus, fetal position, alteration of amniotic fluid volume and gestational age can be factors that may aggravate check-ups. A prerogative for an early prenatal diagnosis of fetal skeletal anomalies is a well organized scan of each and every fetus that checks all bones, starting with the skull and finishing with hands and feet. Should an anomaly be found an extensive detailed scan by an expert should be performed, as well as karyotyping and a consultation with pediatrician/surgeon. In case of a lethal anomaly, an option of pregnancy termination should be considered and if the parents decide against it, the pregnancy should be closely monitored, with parents fully counseled about the prognosis for the child. In this case the anomaly was noted only after the 30th week of gestation and even then only because the patient came because she had some subjective difficulties because of the excessive amniotic fluid volume. On the other hand, some skeletal dysplasias can be diagnosed only in the late second, early third trimester and sometimes stay unnoticed until the end of pregnancy. This case could not be resolved definitely, for the anomalies were conclusive neither of a specific genetic syndrome, nor of an isolated skeletal dysplasia. Extensive further examination of parents as well as their families is needed in order to be able to give some information about the risks in the next pregnancy.

CONCLUSION: Although skeletal anomalies are extremely difficult to diagnose antenatally, a detailed scan of a complete fetal anatomy between 20 and 32 gestational weeks with special attention given to the entire skeleton, gives certain assurance of excluding majority of major skeletal dysplasias or enables their diagnosis and further adequate plan for pregnancy management.