Hydrops fetalis is characterized by accumulation of excess body fluid in extracellular tissues and serous cavities. There are two types of hydrops fetalis: 1. Immune hydrops fetalis, 2. Nonimmune hydrops fetalis. We report a case of nonimmune hydrops fetalis in 35yrs old second gravida, with a previous cesarean section 12yrs back. The patient reported to emergency with perception of reduced fetal movement at 30 weeks 2 days period of gestation and diagnosed as hydrops fetalis. USG report showed single live fetus with 30 weeks 6 days maturity, AFI; 23cm. with fetal ascites, skin thickening, pericardial effusion and bilateral pleural effusion of the fetus. The mother was 'O positive' blood group with insignificant past medical history. On further detailed USG evaluation we detected poor contractility of fetal heart, atrio-ventricular dysplasia, echogenic walls of aorta, pulmonary artery poor elasticity and reduced peak systolic velocity in middle cerebral artery Doppler. A dead baby with nonimmune hydrops fetalis was delivered vaginally. Diagnosis of hydrops fetalis due to cardiac anomaly established after vaginal birth in a post-cesarean pregnancy.
Hydrops fetalis is defined as abnormal accumulation of fluid in two or more fetal compartments, including ascites, pleural effusion, pericardial effusion, and skin edema. It is broadly of two types according to its etiology.
1. Immune Hydrops Fetalis(IHF) and
2. Nonimmune Hydrops Fetalis (NIHF). IHF occurs due to formation of maternal antibody against paternal antigen, usually due to Rh incompatibility. This antibodies cross placenta and cause hemolysis of fetal RBCs. The etiologies of NIHF include cardiovascular abnormalities, placental malformations/problems, hematological problems, congenital infections, noncardiac congenital anomalies, chromosomal aberrations, genetic syndromes, and miscellaneous causes. However cases of NIHF are reported more frequently now-a-days. In this report we present a case of nonimmune hydrops fetalis due to cardiac anomaly.
Case Report :
In present case the 35 years G3P1+1 presented at our OPD for booking on 11.11.2017 at 10 week 1 day. She was advised for routine antenatal tests which included 75 gram glucose challenge test and estimation of thyroid stimulating hormone (TSH) estimation. She was of O positive blood group with no other significant past medical history. She had a history of previous cesarean section 12yrs back, due to term prelabour rupture of membrane. She was diagnosed as gestational diabetes (GDM) and hypothyroidism in this pregnancy. She was put on medical nutrition therapy for GDM. Her HbA1c level was 5.5 though. She was advised tab. levothyroxine 50mcg. On her dating ultrasound scan (USG) there was a disparity of 4 weeks (gestational age by last menstrual period 10 weeks and by ultrasonography it was 14+5/7 weeks). She was immunized with injection tetanus toxoid (0.5 ml) on 29.11.2016 and 3.01.2016 (two doses). She was advised for quadruple test for screening of chromosomal anomalies which was in the low risk range. She underwent routine anomaly scan which was also reported normal. Around 30 weeks gestational period (4.3.2017) she started feeling reduced fetal movements and reported to emergency. She was admitted for observation. In USG it was evident that the fetus had pericardial effusion, pleural effusion, ascites and skin thickening. She then underwent fetal echocardiography which revealed that it had 1) pericardial effusion. 2) poor contractility of the heart. 3) AV dysplasia. 4) MR + TR 5) echogenic walls of aorta 6) poor elasticity of pulmonary artery. 7) decreased peak systolic velocity (PSV) and dampening in middle cerebral artery (MCA).
Figure 1: Pericardial Effusion
Figure 2 : Ascites & Subcutaneous edema
Figure 3 : Scalp Thickening
Figure 4 : Echogenic Walls of Aorta
Figure 5: Reduced PSV and Dampening in MCA
Her Rubella and CMV Ig M, Toxoplasma (Ig G+ Ig M) were negative, although Rubella and CMV IgG were positive. Mother was explained and counseled about the poor prognosis of the fetus and was discharged on request for consultation with pediatric cardiologist and pediatric cardiac surgeons to know more about the possible outcome of such babies if operated. She came back again at emergency on 24.03.2017 with less perception of fetal movement, and upon USG there was intrauterine fetal demise (IUFD). A decision of allowing her a vaginal birth was taken. She eventually delivered a macerated male still born fetus on 26.03.2017.
Fig6: Macerated IUFD with Skin Thickening
Fig7: Limbs Swelling
Fig8: Fetal Ascites and Scrotal Swelling
Normal development of fetus depends upon multiple factors. It is an integrated process of cellular proliferation, differentiation and growth which are governed by the signals from molecular and genetic levels. Any deviation from normal development of fetus may lead to congenital defects ranging from anomalies at cellular level to gross structural anomalies. Hydrops fetalis is one such condition with very poor prognosis and mostly lead to intrauterine fetal death. Hydrops fetalis is a condition characterized by abnormal collection of fluid at minimum two different compartments of fetus. It is due to presence of excess body water in extracellular compartment and serous cavities of the fetus. It is often associated with polyhydramnios and placental thickening. The primary fetal conditions that lead to hydrops fetalis are 1. Fetal anemia 2. Fetal heart failure 3. Fetal hypoproteinaemia. Immune hydrops fetalis occurs due to immunological response to a paternally-derived antigen, by which maternal red cell alloimmunisation takes place. These antibodies bind to antigens present on the fetal erythrocytes after crossing the placenta and cause hemolysis and hydrops fetalis . The relative incidence of immune hydrops fetalis (IHF) has dramatically reduced in past two decades due to Rh anti D prophylaxis.
Non immune hydrops fetalis(NIHF) is usually not associated with hemolysis of fetal RBCs. The most common causes associated with NIHF are structural abnormalities of heart, cardiac arrhythmias, tumors, physiological dysfunction of heart due to infection, inflammation, infarction and arterial calcification, cardiac tumors, cardiomyopathy account for about 10 to 20% of cases of non-immune hydrops fetalis[2-4]. In this case the cause of NIHF is major cardiac anomalies-Atrio-ventricular dysplasia and poor contractility of heart, leading to intrauterine cardiac failure, which is further evidenced by reduced peak systolic velocity in middle cerebral artery (MCA) Doppler.
In general NIHF is regarded to have poor prognosis and usually termination of pregnancy is advisable. But thorough evaluation is needed to detect to cause of NIHF. If once detected, it can be further evaluated by non-invasive tests like comprehensive ultrasound examination, by fetal echocardiogram, by carefully looking for structural fetal anomalies or genetic syndromes, by signs of fetal infection, and by looking for evidence of umbilical cord or placental anomalies. Invasive tests like fetal karyotyping are also suggested in cases of unexplained hydrops. In various studies it has been evidenced that although the outcome is very poor, still it varies depending upon the etiology of NIHF. Spontaneous abortion, intrauterine fetal death, or pregnancy termination of all 30 cases of non-immune hydrops fetalis diagnosed between 10 and 14 weeks of gestation has been reported. In cases with major cardiac anomalies or other causes where intrauterine heart failure is inevitable, termination of pregnancy is advised. There are also some correctable causes of NIHF like some congenital heart disease and some cases of diaphragmatic hernia.
With advancement of Rh anti D prophylaxis, 90 percent of cases of hydropsfetalis is contributed by non immune causes. Although the prognosis of NIHF is very poor, early detection and evaluation may help obstetricians to handle the treatable and recurrent cases.