Pregnancy Outcome Following Second-Trimester Amniocentesis: A Case-Control Study

ABSTRACT

The purpose of this study was to investigate whether second-trimester amniocentesis increases fetal loss rate. Two thousand sixty-eight women with singleton gestations who underwent mid-trimester amniocentesis at 15 to 22 weeks gestation and 2068 controls matched one-to-one for maternal age, parity, and the number of prior spontaneous abortions were studied prospectively in a case-control study design. The fetal loss rates and other adverse pregnancy outcomes were compared between the study and control groups using the Pearson χ² test or Fisher exact test when appropriate. In the amniocentesis group, eight (0.4%) fetal losses occurred within 30 days of the procedure, and in the control group, six (0.3%) losses occurred within 30 days of the inclusion in the study; the difference was not statistically significant (p = 0.59; OR, 1.34; 95% CI, 0.46 to 3.85). The total fetal loss rates including spontaneous abortions and intrauterine fetal deaths/stillbirths were 2.3 and 2% in the study and control groups, respectively, and the difference was not significant (p = 0.59; OR, 1.12; 95% CI, 0.74 to 1.71). Amniotic fluid leakage occurred in only two (0.1%) of 2068 study patients. Transplacental needle passage was not associated with an increased risk of pregnancy loss compared with nontransplacental amniocentesis (p = 0.92; OR, 0.96; 95% CI, 0.47 to 1.95). There was no statistically significant difference in fetal loss rate between women requiring two needle insertions to obtain amniotic fluid and those having only one insertion (p = 1.00; OR, 0.75; 95% CI, 0.10 to 5.53). The rates of preterm deliveries, small for gestational age infants, preeclampsia/eclampsia, placental abruptions, and cesarean deliveries were also not significantly different between two groups (each p > 0.05). We conclude that second-trimester amniocentesis for prenatal diagnosis is a safe procedure that does not appear to increase fetal loss rate.

KEYWORDS

Second-trimester amniocentesis - fetal loss - pregnancy outcome

REFERENCES

• 1 Tabor A, Philip J, Madsen M, Bang J, Obel E B, Norgaard-Pedersen B. Randomised controlled trial of genetic amniocentesis in 4606 low-risk women.  Lancet. 1986;  1 1287-1293
• 2 An assessment of the hazards of amniocentesis: report to the Medical Research Council by their Working Party on amniocentesis.  Br J Obstet Gynaecol. 1978;  85(suppl 2) 1-41
• 3 Muller F, Thibaud D, Poloce F et al.. Risk of amniocentesis in women screened positive for Down syndrome with second trimester maternal serum markers.  Prenat Diagn. 2002;  22 1036-1039
• 4 Tongsong T, Wanapirak C, Sirivatanapa P, Piyamongkol W, Sirichotiyakul S, Yampochai A. Amniocentesis-related fetal loss: a cohort study.  Obstet Gynecol. 1998;  92 64-67
• 5 NICHD National Registry for Amniocentesis Study Group . Midtrimester amniocentesis for prenatal diagnosis: safety and accuracy.  JAMA. 1976;  236 1471-1476
• 6 Porreco R P, Young P E, Resnik R et al.. Reproductive outcome following amniocentesis for genetic indications.  Am J Obstet Gynecol. 1982;  143 653-660
• 7 Hanson F W, Tennant F R, Zorn E M, Samuels S. Analysis of 2136 genetic amniocenteses: experience of a single physician.  Am J Obstet Gynecol. 1985;  152 436-443
• 8 Marthin T, Liedgren S, Hammar M. Transplacental needle passage and other risk-factors associated with second trimester amniocentesis.  Acta Obstet Gynecol Scand. 1997;  76 728-732
• 9 Bombard A T, Powers J F, Carter S, Schwartz A, Nitowsky H M. Procedure-related fetal losses in transplacental versus nontransplacental genetic amniocentesis.  Am J Obstet Gynecol. 1995;  172 868-872
• 10 Silver R K, Russell T L, Kambich M P, Leeth E A, MacGregor S N, Sholl J S. Midtrimester amniocentesis: influence of operator caseload on sampling efficiency.  J Reprod Med. 1998;  43 191-195
• 11 Blessed W B, Lacoste H, Welch R A. Obstetrician-gynecologists performing genetic amniocentesis may be misleading themselves and their patients.  Am J Obstet Gynecol. 2001;  184 1340-1344
• 12 Blackwell S C, Abundis M G, Nehra P C. Five-year experience with midtrimester amniocentesis performed by a single group of obstetricians-gynecologists at a community hospital.  Am J Obstet Gynecol. 2002;  186 1130-1132
• 13 Ogle R, Jauniaux E, Pahal G, Dell E, Sheldrake A, Rodeck C. Serum screening for Down syndrome and adverse pregnancy outcomes: a case-controlled study.  Prenat Diagn. 2000;  20 96-99
• 14 Van Rijn M, Van Der Schouw Y T, Hagenaars A M, Visser G HA, Christiaens G CML. Adverse obstetric outcome in low- and high-risk pregnancies: predictive value of maternal serum screening.  Obstet Gynecol. 1999;  94 929-934
• 15 Crandall B F, Howard J, Lebherz T B, Rubinstein L, Sample W F, Sarti D. Follow-up of 2000 second-trimester amniocenteses.  Obstet Gynecol. 1980;  56 625-628
• 16 Brumfield C G, Lin S, Conner W, Cosper P, Davis R O, Owen J. Pregnancy outcome following genetic amniocentesis at 11-14 versus 16-19 weeks' gestation.  Obstet Gynecol. 1996;  88 114-118
• 17 The Canadian Early and Mid-Trimester Amniocentesis Trial (CEMAT) Group . Randomised trial to assess safety and fetal outcome of early and midtrimester amniocentesis.  Lancet. 1998;  351 242-247
• 18 Smidt-Jensen S, Permin M, Philip J et al.. Randomised comparison of amniocentesis and transabdominal and transcervical chorionic villus sampling.  Lancet. 1992;  340 1237-1244
• 19 Crane J P, Kopta M M. Genetic amniocentesis: impact of placental position upon the risk of pregnancy loss.  Am J Obstet Gynecol. 1984;  150 813-816
• 20 Saltvedt S, Almstrom H. Fetal loss rate after second trimester amniocentesis at different gestational age.  Acta Obstet Gynecol Scand. 1999;  78 10-14
• 21 Laing F C, Frates M C. Ultrasound evaluation during the first trimester of pregnancy. In: Callen PW Ultrasonography in Obstetrics and Gynecology. Philadelphia; WB Saunders 2000: 105-145
• 22 Cederholm M, Haglund B, Axelsson O. Maternal complications following amniocentesis and chorionic villus sampling for prenatal karyotyping.  BJOG. 2003;  110 392-399