Abstract
Objective:
The purpose of this study was to evaluate miscarriage after mid-trimester amniocentesis for abnormal maternal serum screening.

Study Design:
An analysis of summary data from the California State maternal serum screening program on 32,050 women with an abnormal serum screen, a singleton fetus, and normal ultrasound was performed. Miscarriage before 24 weeks, days until miscarriage, gestational age at miscarriage, and maternal factors were compared. The power of this study could detect a 50% increase in miscarriage.

Results:
The miscarriage rate with amniocentesis, 0.46% (69/15,005), was no different than without, 0.53% (90/17,045), P=.38. There was no difference in maternal age, serum biochemical factors, gestational age at miscarriage (21.1 weeks for both groups), or days until miscarriage (23 after amniocentesis and 20.4 without). Log-rank test revealed no difference for gestational age at miscarriage (P=.61) or number of days until miscarriage (P=.40).

Conclusion:
The rate and timing of miscarriage was similar with or without amniocentesis in California women with abnormal maternal serum screening (Figs 1-3).

 

Figure 1: Days after prenatal diagnosis visit until miscarriage. Cumulative miscarriages: days until miscarriage after prenatal diagnosis evaluation (Log-rank test: P=.4). (Reprinted from Towner D, Currier RJ, Lorey FW, et al. Miscarriage risk from amniocentesis performed for abnormal maternal serum screening. Am J Obstet Gynecol. 2007;196:608.e1-608.e5, with permission from Elsevier.)

Figure 2: Gestational age at miscarriage. Cumulative miscarriage: gestational age at miscarriage (Log-rank test: P=.61). (Reprinted from Towner D, Currier RJ, Lorey FW, et al. Miscarriage risk from amniocentesis performed for abnormal maternal serum screening. Am J Obstet Gynecol. 2007;196:608.e1-608.e5, with permission from Elsevier.)

Figure 3: Gestational age at miscarriage stratified by week of gestation in which prenatal diagnosis evaluation occurred. ANOVA: P=.75. (Reprinted from Towner D, Currier RJ, Lorey FW, et al. Miscarriage risk from amniocentesis performed for abnormal maternal serum screening. Am J Obstet Gynecol. 2007;196:608.e1-608.e5, with permission from Elsevier.)