Prenatal sonographic detection of birth defects in 18 hospitals from South America.

OBJECTIVE: The purpose of this study was to assess the accuracy of prenatal sonographic diagnosis of birth defects and the gestational age at detection according to the health insurance schemes of mothers in 450 malformed neonates from 18 South American hospitals on the basis of prenatal sonographic records. METHODS: Between July 2000 and December 2003, 18 hospitals included in the Latin American Collaborative Study of Congenital Malformations (13 from Argentina [8 public and 5 nonpublic], 3 from Brazil [2 public and 1 nonpublic], 1 from Chile [nonpublic], and 1 from Venezuela [public]) voluntarily participated in this prospective observational study, recording fetuses with sonographically detected malformations. Prenatal sonographic descriptions of anomalies were compared with those recorded at birth. RESULTS: Of 812 anomalies detected at birth, 457 had been prenatally detected (detection rate, 56.3%; 95% confidence interval, 52.8%-59.8%). Before 24 gestational weeks, anencephaly had the highest detection rate. Cleft lip and clubfoot were more easily detected when associated with other anomalies. The detection rates for central nervous system and renourinary malformations were greater than 80%. Detection rates between both health insurance schemes (public and nonpublic) did not show significant differences, but anencephaly, spina bifida, renourinary defects, and cleft lip with or without cleft palate were detected earlier in patients from nonpublic rather than in public hospitals. CONCLUSIONS: For specific anomalies, South America shows similar levels of prenatal sonographic detection as developed countries. Detection rates during pregnancy were similar for public and nonpublic hospitals, whereas cases were diagnosed earlier in patients from nonpublic hospitals.

Discordance of cord insertions as a predictor of discordant fetal growth in monochorionic twins.

INTRODUCTION: The type of cord insertion within monochorionic twin pairs could be different. The purpose of study is to evaluate the association of different combinations of placental umbilical cord insertions with birth weight discordance in a large cohort of monochorionic twins. METHODS: All consecutive monochorionic placentas from either uncomplicated twin pregnancies or with fetal weight discordance examined and injected with color dye at our centers were included in this study (n = 374). Marginal or velamentous cord insertions were defined as abnormal. Placentas were categorized as concordant when the cord insertions of both fetuses were either normal-normal or abnormal-abnormal, and as discordant when they were normal-abnormal. Birth weight discordance was defined as a difference in birth weight of each twin ≥25%. The association of different cord insertion combinations with birth weight discordance was analyzed. RESULTS: The rate of discordant cord insertions was 55% (204/374) in monochorionic twins. A highly significant association between discordant cord insertions and discordant birth weight was observed (p < 0.01). The odds ratios (OR) for birth weight discordance in the discordant cord insertion group compared with the concordant group were 2.3 (95% CI: 1.2-4.4) for the normal-marginal and 5.9 (95% CI: 3.8-10.4) for the normal-velamentous cord insertion subgroup. Discordant cord insertions are associated with the occurrence of unequal placental sharing (OR 4.3, 95%CI 2.7-6.9). DISCUSSION: Discordance of cord insertions is associated with discordance of birth weight and may therefore be an important indicator of adverse outcome in monochorionic twins.