Echographic Screening for Fetal Malformations at the Gynecological and Obstetric Clinic of the Aristide Le Dantec Hospital: Review from 2016 to 2018

Abstract

Introduction: Congenital malformations affect around 3% to 4% of live births and 20% of stillbirths. They represent 20 to 30% of the causes of infant mortality in the countries of the European Community. It is estimated that 5 to 10% of malformations are due to exogenous or environmental causes and 12 to 30% to genetic or endogenous causes (gene mutations or chromosomal anomalies). In almost 60% of cases, the actual origin of the malformation remains unknown. Nevertheless, the origin of these anomalies is still being researched, and numerous diagnostic tools are available to practitioners to improve antenatal screening and pregnancy monitoring. However, obstetric ultrasound remains the primary tool for antenatal screening and monitoring of congenital malformations. Methodology: Our main objective was to evaluate the practice of ultrasound screening for foetal malformations at the Gynaecology and Obstetrics Clinic at Hopital Aristide Le Dantec from 1 February 2016 to 31 December 2018. We conducted a retrospective study of ultrasound screening for foetal malformations. Results: At the end of our study, 869 obstetric ultrasounds met our inclusion criteria. We had 837 singleton pregnancies (96.3%), 31 twin pregnancies (3.6%) and 1 trimellar pregnancy (0.1%). We noted 35 cases of foetal malformations, an incidence of 4.02%. All cases of malformations were diagnosed in singleton pregnancies. The average age of the patients was 29 years, with extremes of 18 and 45 years. Primiparous women were the most represented in our study (62.5%). The majority of patients were from Dakar. A history of recurrent miscarriage was found in 7 patients (20%) and there was one case of fetal death in utero during the previous pregnancy. There was no family history of malformations. Consanguinity was found in 11 cases (31.4%). Only 2 patients were found to have taken medication, one for insulin and the other for an unspecified drug. There was no evidence of toxic intake. Fetal malformations were observed in the 3rd trimester in 23 cases (42.9%). There were 11 cases in the 2nd trimester (31.4%) and only 1 case in the 1st trimester. Cranioencephalic malformations were detected in almost half of the cases (42.8%), i.e. 15 cases. There were 8 cases of polymalformative syndromes, i.e. 22.8%. Digestive malformations were represented in 3 cases, i.e. 8.6%, as were cardiac malformations in 3 cases. Pulmonary malformations and limb malformations accounted for 5.7% and 2 cases each. Renal malformations and orofacial malformations also accounted for 1 case each, 2.9% respectively. Among the 15 cases of malformations of the nervous system, ventricular dilatation ranked first with 10 cases representing 66.6%, followed by anencephaly and cystic hygroma with 2 cases each representing 13.3% and finally dolichocephaly with 1 case representing 6.7%. We found 8 different cases of polymalformative syndromes. These syndromes were labelled in 2 cases and unlabelled in the 6 others. There was 1 case of trisomy 21 and 1 case of trisomy 13. The other cases of polymalformative syndromes were not clearly labelled. A combination of cerebral, $cardiac and/or renal malformations were reported. Digestive malformations were noted in 3 cases (8.6%), including 2 dilatations of the coves (megacolon) and 1 case of omphalocele. Pericarditis, atrial septal defect and transposition of the great vessels were the cardiac malformations found in a total of 3 cases (8.6%). Two cases of achondroplasia were found in our series (5.7%). They were all associated with oligohydramnios. There were 2 cases of pulmonary hypoplasia (5.7%). These were associated with anamnios and a medullary syndrome in one of the cases. Cleft lip and palate and polycystic kidney disease were present in one case each (2.9%). The pregnancy resulted in vaginal delivery in 21 cases (60%), caesarean section in 13 cases (37.1%) and in 1 case the mode of delivery was not specified. The main indication for Caesarean section was hydrocephalus (61.5%). The anomaly and the type of malformation were announced in 85.5% of cases. A referral for fetal ultrasound was suggested in 5.7% of patients and fetal MRI in 2.9%. Concordance between antenatal and postnatal diagnosis was achieved in 18 cases (51.4%). The pregnancy resulted in vaginal delivery in 21 cases (60%), caesarean section in 13 cases (37.1%) and in 1 case the mode of delivery was not specified. The main indication for Caesarean section was hydrocephalus (61.5%). The anomaly and the type of malformation were announced in 85.5% of cases. A referral for fetal ultrasound was suggested in 5.7% of patients and fetal MRI in 2.9%. Concordance between antenatal and postnatal diagnosis was achieved in 18 cases (51.4%). Neonatal mortality accounted for 62.9% of the series, with 22 cases. Conclusion: Fetal malformations were detected with a concordance of 51.4% between antenatal and postnatal diagnosis. Neonatal mortality was high. A major preoccupation should be the strengthening of cytogenetic diagnosis and management resources, and raising awareness of the origins of congenital malformations.