There is also short clips of the neonate.
On a 2 month follow-up after birth, the baby has had a good clinical outcome.
History: It has been shown experimentally as well as clinically that indomethacin constricts the fetal ductus arteriosus. There are 9 reported cases of prenatal diagnosis of spontaneous (no drug induced) premature closure of the ductus arteriosus1,2,3,4, and all of them had the same findings seen in this case, except for the oligohydramnios (some cases mention polyhydramnios). There is a pathology report of 800 perinatal necropsies where 3 stillborn infants were found to have an almost completely closed ductus arteriosus. Each of these showed cardiomegaly, dilatation of right side chambers, and pulmonary hyperaemia. Intrauterine death was considered to be due to premature closure of the ductus arteriosus5,6.
Etiology: Patency of the ductus arteriosus is no longer maintained during gestation by locally produced and circulating prostaglandins, and the ductus becomes more sensitive to constricting factors such as prostaglandins synthetase inhibitors7,8,9
Pathogenesis: As the ductus arteriosus closes in the fetus, blood from the right heart is totally directed to the high resistance fluid-filled lungs, resulting in increased right ventricular afterload, impaired right ventricular function, and consequently tricuspid regurgitation and right heart dilatation. After birth, blood flow from the right heart goes through low resistive air filled lungs, diminishing right ventricular afterload, which solves the heart chambers disproportion in the newborn.
Sonographic findings: In every reported case of PCDA there have been consistent findings: cardiomegaly, dilatation of pulmonary arteries, the main pulmonary artery and the right ventricle and atria. Tricuspid regurgitation, and no visualization of ductus arteriosus in all its extension. Hydrops has been described in previous reports3. In this case PCDA was associated to severe oligohydramnios.
Differential diagnosis: The most common causes of right heart dilatation appearing in the third trimester are:
1. Coarctation of the aorta. This can be ascertained by evaluating the size of the ascending aorta (usually small), and the transverse arch. Usually bi-directional flow is present in the transverse arch.
2. Significant placental dysfunction. Usually the outflow tracts measure normal. There may be bi-directional flow in the transverse arch, but not as much as with coarctation.
3. Constriction or closure of the ductus arteriosus.
Associated anomalies: There are no reports of associations with other anomalies.
Prognosis: Delaying delivery compromises very seriously the survival of the fetus. Urgent delivery results in an excellent prognosis.
1- Chao RC, Ho ES, Hsieh KS: Doppler echocardiographic diagnosis of intrauterine closure of the ductus arteriosus. Prenat Diagn 1993 Oct; 13(10): 989-94
2- Hofstadler G, Tulzer G, Altmann R, Schmitt K, Danford D, Huhta JC. Spontaneous closure of the human fetal ductus arteriosus. A cause of fetal congestive heart failure. Am J Obstet Gynecol 1996 Mar; 174(3): 879-83
3- Leal SD, Cavalle-Garrido T, Ryan G, Farine D, Heilbut M, Smallhorn JF. Isolated ductal closure in utero diagnosed by fetal echocardiography. Am J Perinatol 1997 Apr; 14(4): 205-10
4- M. Y. Park, Y.J. Kim, B.H. Woo and H.S. Kim S-shaped kinking and constriction of the fetal ductus arteriosus with pericardial effusion
Ultrasound in Obstetrics and Gynecology Volume 16 issue s1 Page 93 October 2000.
5- Kohler HG. Premature closure of the ductus arteriosus (P.C.D.A.): A possible cause of intrauterine circulatory failure. Early Hum Dev 1998 Apr; 2(1): 15-23
6- Becker AE, Becker MJ, Wagenvoort CA. Premature contraction of the ductus arteriosus: a cause of fetal death. J Pathol 1977 Mar;121(3): 187-91
7- Truter PJ, Franszen S, van der Merwe JV, Coetzee MJ. Premature closure of the ductus arteriosus causing intra-uterine death. A case report. S Afr Med J 1986 Oct 25; 70(9): 557-8
8- Huhta JC, Cohen AW, Wood DC. Premature constriction of the ductus arteriosus. J Am Soc Echocardiogr 1990 Jan-Feb; 3(1): 30-4
9- Tumbarello R, Pisu F, Pisano E, Puddu R, Bini RM. Timely detection of premature closure of the ductus arteriosus in a full-term fetus. Important role of fetal echocardiography. Minerva Ginecol 1999 May; 51(5): 197-201