Journals | Policy | Permission

Journal of Clinical Gynecology & Obstetrics

Original Article

Volume 6, Number 2, June 2017, pages 34-36

Complications Associated With Amniocentesis in the Third Trimester of Pregnancy

Amnion puncture is an invasive technique for obtaining a sample of amniotic fluid by aspiration into the amniotic cavity using a needle via transabdominal [1-3]. Amniocentesis may be performed for diagnostic or therapeutic purposes. In the case of a diagnostic procedure, the sample of amniotic fluid is used to perform histopathological or biochemical studies, while in the case of a therapeutic procedure, this is intended to reduce the volume of amniotic fluid in patients with polyhydramnios [1-3]. According to the stage of gestation at which the amniocentesis is performed, it is classified into early, middle and late or third trimester. At present, the latter is mainly used to determine fetal lung maturity, passing to second term other applications [3, 4]. The respiratory distress syndrome is a significant cause of neonatal morbidity and mortality, therefore the assessment of fetal lung maturity with the amniocentesis test plays an important role in obstetric decisions. In this case, the lecithin-sphingomyelin index and/or lamellar bodies and the Clements test are realized with amniotic liquid obtained during the third trimester [1, 5, 6].

Amniocentesis is not an innocuous procedure; therefore indications, benefits and potential risks involved in the procedure should be carefully explained to the patient and family. The amniocentesis performed during the third trimester under ultrasound guidance is safe and effective. The major complications associated with the procedure are premature rupture of membranes, fetal direct and indirect injury, amniotic infection and fetal loss. On the other hand, puncture of abdominal viscera, hemorrhage and isoimmunization are rare maternal complications [4, 7, 8]. Complications due to amniocentesis have been reported in the first 48 h after the procedure that merit urgent resolution of pregnancy or before the completion of lung maturity. These include alterations in fetal heart rate, placental hemorrhage, placental abruption, uterine rupture, preterm labor and rupture of membranes [4, 9-11]. The total rate of pregnancy loss after amniocentesis varies from 0.3% to 11.2% [4, 10, 12-15]. That complication has been related to factors associated with the technique used, the placental insertion and gestational age. Publications of the complications associated to amniocentesis have been infrequent in our country. Therefore, the objective of this study was to determine the complications of the amniocentesis during the third trimester and the factors associated with these complications in a population of Mexican women.

This is a retrospective, descriptive study through the review of clinical records of women whose pregnancies were followed from 2008 to 2011. The study was performed in a public obstetrics and gynecology tertiary-care hospital in an urban part of Mexico. The hospital provides care for patients of lower and middle socioeconomic status. The Ethics and Investigation Committees approved the study protocol, and the study was performed according to the guidelines delineated by the Declaration of Helsinki.

Amniocentesis under ultrasound guidance was performed to the women during the third trimester. Sociodemographic variables, amniocentesis indications, gestational age at the procedures, number of punctures to obtain amniotic fluid, and maternal and fetal complications were obtained from the clinical records. Amniocentesis was performed by two operators using the technique known as “hands-free”. One operator locates the puncture site by ultrasound, while the second operator performs puncture with a spinal needle number 20 and making the extraction of amniotic fluid [3].

Major complications were defined as those that potentially led to the termination of pregnancy (premature rupture of membranes, uncorrectable bleeding, and uncontrolled uterine activity), whereas minor complications were considered those that did not alter the course of pregnancy and whose appearance is directly associated with carrying out the process (sample contamination, uterine contractions, and leakage of amniotic fluid transvaginal). Statistical analysis was realized using the Statistical Package for Social Sciences (SPSS). Frequencies, percentage, central tendency and dispersion measures were obtained.

A total of 205 women were included in the study (Table 1). The mean patient age was 27.0 ± 7.3 years, with a minimum age of 14 years and a maximum age of 45 years. Forty-two patients were multigravida women (20.7%).

Click to view

Table 1. Clinical Characteristics of Women Included in the Study (n = 203)

Two hundred forty-nine amniocentesis procedures were completed, with an average of 1.2 events/patient, with a minimum of one procedure and a maximum of four procedures. One puncture was realized in 69.5% (n = 173) of cases and two or more punctures were performed in 30.5% (n = 76) of cases.

Assessment of fetal lung maturity (n = 223; 89.6%), reduction of amniotic liquid (n = 16; 6.4%), and both indications (n = 10; 4.0%) were the main indications for amniocentesis.

In the case of pathological personal history, intrauterine growth restriction (n = 69; 34%), alterations in carbohydrate metabolism (n = 53; 26%), twin pregnancy (n = 22; 11%), pregnancy-induced hypertensive disease (n = 16; 8%), poly-oligohydramnios (n = 14; 7%) and others (n = 29; 14%) were the major comorbidities associated with gestation.

The mean gestational age at the moment of the procedure was 36.7 ± 2.8 weeks, with a difference of 2 weeks regarding the mean gestational age obtained by ultrasound (34.3 ± 2.3 weeks gestation).

Eighteen (7.2%) complications due to the amniocentesis procedure were found in the present study. The incidence of minor complications was 5.6% (n = 14). In this sense, hematic amniotic liquid was obtained in 10 cases (4.02%) and uterine contractility occurred in four cases (1.6%). The incidence of major complications was 1.6% (n = 4). Membranes premature rupture occurred in two cases (0.8%) and placenta premature separation occurred in two cases (0.8%).

In the present study, no fetal loss occurred or was registered despite of the complications of the procedures.

The median of the time for resolution of pregnancy after amniocentesis was 24 h and it was mainly via cesarean birth (86.3%; n = 177), either because comorbidities were presented by patients or because the fetal maturity was confirmed.

Amniocentesis is not an innocuous procedure; there are complications that can compromise the health of the mother and fetus. The most important concerns in assuring the safest possible execution of the procedure include adherence to correct indications for the procedure, the presence of an expert operator and the use of ultrasound guidance [13-15].

According to the literature, the greatest concern for most couples deciding whether to undergo diagnosis amniocentesis is the likelihood of fetal loss [14]. In this sense, the rate of amniocentesis-related pregnancy loss mentioned in the literature ranged between 0.3% and 11.2% [12-15]. However, several studies have reported a miscarriage rate that has not been found different between women who chose amniocentesis and those who did not. For example, in a study with 2,256 women that undergoing amniocentesis, pregnancy loss occurred in 1.8% of women compared with 1.4% of controls women, being a non-significant difference [13]. In another study with more than 32,000 pregnant women, there was no significant difference in the miscarriage rate between women who chose amniocentesis and those who not [16]. In our study, the placenta premature separation forcing immediate birth occurred in two patients (0.8%). This pregnancy loss rate observed in our study was the same as that procedure-related fetal loss rate published by Haraldsdottir et al [17] of 0.8% on women who had amniocentesis and chorionic villus sampling in the Prenatal Diagnosis Unit at the Landspitali University Hospital during 1998 - 2007. However, it is important to clarify that these complications published by above authors were derived from studies of amniocentesis in the second quarter [17].

Factors that are associated with increased fetal loss rates include a transplacental approach, multiple needle insertions, larger needle caliper, an abnormal fetus, and potentially operator experience [13, 18]. It should be noted that in our study there were no fetal deaths related to the amniocentesis.

On the other hand, the overall incidence (7.2%) of complications (different to pregnancy loss) associated with amniocentesis in pregnant women in our study was practically the same as the incidence of 7.9% reported by Hernandez et al [10]. However, the percentage of minor complications in our study was slightly lower than that rate published by Hernandez et al [10] (5.6% versus 7.2%). Importantly, there are differences in both populations due to the characteristics of our unit, considered as a reference center without strict entry criteria. Likewise, another difference between the results of the study of Hernandez et al [10] and our study was the number of procedures by patients, being of 1.2 events/patient in our study versus 2.8 events/patient. The multiple needle insertion is a risk factor that is associated with complications due to amniocentesis [13, 18].

In conclusion, the complications rates observed in our study indicated that amniocentesis is still a valid therapeutic and/or diagnostic tool in those patients who have indications for the realization of the procedure.

Conflicts of Interest

The authors have no conflicts of interest relevant to this article.

1. Elliott JP, Urig MA, Clewell WH. Aggressive therapeutic amniocentesis for treatment of twin-twin transfusion syndrome. Obstet Gynecol. 1991;77(4):537-540.
   pubmed
2. Piantelli G, Bedocchi L, Cavicchioni O, Verrotti C, Cavallotti D, Fieni S, Gramellini D. Amnioreduction for treatment of severe polyhydramnios. Acta Biomed. 2004;75(Suppl 1):56-58.
   pubmed
3. Nizard J. Amniocentesis: technique and education. Curr Opin Obstet Gynecol. 2010;22(2):152-154.
   doi pubmed
4. Zalud I, Janas S. Risk of third-trimester amniocentesis. J Reprod Med. 2008;53(1):45-48.
   pubmed
5. Carpenter RJ Jr, Hinkley CM, Carpenter AF. Midtrimester genetic amniocentesis. Use of ultrasound direction vs. blind needle insertion. J Reprod Med. 1983;28(1):35-40.
   pubmed
6. de Crespigny LC, Robinson HP. Amniocentesis: a comparison of 'monitored' versus 'blind' needle insertion technique. Aust N Z J Obstet Gynaecol. 1986;26(2):124-128.
   doi pubmed
7. Benacerraf BR, Frigoletto FD. Amniocentesis under continuous ultrasound guidance: a series of 232 cases. Obstet Gynecol. 1983;62(6):760-763.
   pubmed
8. Stark CM, Smith RS, Lagrandeur RM, Batton DG, Lorenz RP. Need for urgent delivery after third-trimester amniocentesis. Obstet Gynecol. 2000;95(1):48-50.
   doi
9. Galle PC, Meis PJ. Complications of amniocentesis: a review. J Reprod Med. 1982;27(3):149-155.
   pubmed
10. Hernandez-Andrade E, Leis Marquez MT, Ahued-Ahued R. Complicaciones asociadas al uso de amniocentesis diagnostica en la segunda mitad del embarazo, realizada con o sin guia ultrasonografica continua. Perinatol Reprod Hum. 2000;14(1):7-13.
11. Gordon M, Narula K, O'Shaughnessy R, Barth W. Complications of third trimester amniocentesis using continuous ultrasound guidance. Obstet Gynecol. 2002;99(2):255-259.
    doi
12. Vink J, Fuchs K, D'Alton ME. Amniocentesis in twin pregnancies: a systematic review of the literature. Prenat Diagn. 2012;32(5):409-416.
    doi pubmed
13. Tongsong T, Wanapirak C, Sirivatanapa P, Piyamongkol W, Sirichotiyakul S, Yampochai A. Amniocentesis-related fetal loss: a cohort study. Obstet Gynecol. 1998;92(1):64-67.
    doi
14. Blackwell SC, Abundis MG, Nehra PC. Five-year experience with midtrimester amniocentesis performed by a single group of obstetricians-gynecologists at a community hospital. Am J Obstet Gynecol. 2002;186(6):1130-1132.
    doi pubmed
15. Agarwal K, Alfirevic Z. Pregnancy loss after chorionic villus sampling and genetic amniocentesis in twin pregnancies: a systematic review. Ultrasound Obstet Gynecol. 2012;40(2):128-134.
    doi pubmed
16. Towner D, Currier RJ, Lorey FW, Cunningham GC, Greve LC. Miscarriage risk from amniocentesis performed for abnormal maternal serum screening. Am J Obstet Gynecol. 2007;196(6):608 e601-605; discussion 608 e605.
17. Haraldsdottir KR, Gottfredsdottir H, Geirsson RT. [Fetal loss after amniocentesis and chorionic villus sampling in Iceland]. Laeknabladid. 2014;100(3):147-151.
    pubmed
18. Akolekar R, Beta J, Picciarelli G, Ogilvie C, D'Antonio F. Procedure-related risk of miscarriage following amniocentesis and chorionic villus sampling: a systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2015;45(1):16-26.
    doi pubmed

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial 4.0 International License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Journal of Clinical Gynecology and Obstetrics is published by Elmer Press Inc.