Early Amniocentesis and Congenital Foot Deformities

Abstract

Objective: Several studies have shown an increased risk of congenital foot derformities after early amniocentesis. These studies have comprised amniocenteses performed before 13 completed gestational weeks. In this study, the risk of foot deformities after amniocentesis performed at 12–14 completed gestational weeks was determined. Methods: 3,469 genetic amniocenteses in singleton pregnancies performed before 15 completed gestational weeks were studied. The intention was to perform the amniocenteses at 12–14 weeks of gestation, but 32 amniocenteses were performed at the gestational age 11 weeks + 5 days or 11 weeks + 6 days. The pregnancies were followed up with regard to fetal loss and leakage of amniotic fluid. After birth, newborns with a diagnosis of foot deformity were identified from the Swedish Medical Birth Registry. The observed number of foot deformities was then compared with the expected number which was calculated stratified for delivery hospital, year of birth, and maternal age. Results: The observed number of foot deformities was significantly higher than the expected: exact odds ratio 1.74 (exact 95% confidence interval 1.06–2.69). The rate of spontaneous abortions after the procedure was 1.8%, and the rate of leakage of amniotic fluid was 1.9%. There was a significant trend for all complications to decrease with increasing gestational age at amniocentesis. Conclusion: Women undergoing amniocentesis at 11+5 to 14+6 gestational weeks have an increased risk of giving birth to a child with a congenital foot deformity.

Late First-Trimester Invasive Prenatal Diagnosis: Results of an International Randomized Trial

“…Sundberg et al 12 found an excess risk of talipes equinovarus after early amniocentesis up to 88 days (12 ϩ4 weeks) compared with CVS at 10 -12 weeks. Our study demonstrates an increased risk at 13 ϩ0 to 13 ϩ6 weeks, and 2 recent observational studies 18,19 also support this inverse relationship of gestational age and risk.…”

Prenatal diagnosis of congenital genu recurvatum following amniocentesis complicated by leakage

“…Possible etiological factors for this condition include shortening of the quadriceps secondary to fibrosis of ischemic origin9. Women undergoing amniocentesis at 11 + 5 to 14 + 6 weeks' gestation have an increased risk of giving birth to a child with congenital foot deformity10, and this increased risk may be limited to amniocenteses performed before the 13th week of gestation11.…”

Congenital clubfoot

“…The strongest evidence for an environmental, though intrauterine, cause is from research on the outcome of amniocentesis [12][13][14]. Early amniocentesis (EA=11-12 gestational weeks + 6 days) was associated with ten times higher rate of clubfoot than mid-trimester amniocentesis (MA = 15-16 + 6), or if this procedure was not performed [14].…”