TERMINATION OF PREGNANCY FOR CONGENITAL ANOMALIES IN THE U.S.: A SYSTEMATIC REVIEW AND META-SYNTHESIS BY AMY CATALANO, ED.D, MLS, MALS, ASSOCIATE PROFESSOR OF LIBRARY SERVICES AND MARTINE HACKETT, PH.D, MPH, ASSISTANT PROFESSOR OF HEALTH PROFESSIONS
Abstract
Results
Discussion
Three percent of all pregnancies are affected by a fetal abnormality. Many of these pregnancies are terminated, usually in the second trimester. In order to determine the extent to which fetuses affected by different anomalies are terminated, as well as the factors contributing to decisions to terminate, we systematically searched health and medicine databases for empirical studies that included abortion rates for populations of fetuses prenatally diagnosed with a congenital anomaly in the United States. We ultimately reviewed 79 studies. In addition to reporting termination rates by anomaly, we qualitatively examined the themes that emerged from both the discussion of the results and the conclusions. One of the themes that emerged was that the presence of additional, related anomalies contributed to the decision to terminate. Termination rates tend to vary widely depending on the socioeconomic and demographic characteristics of the mothers as well as the perceived severity of the anomaly. Additionally, the context of who and where prenatal counseling took place all had an impact on parental decision making. Early prenatal diagnosis was also identified as a major implication for many of these studies, as earlier diagnoses may lead to an earlier termination.
We identified 79 studies that met our search parameters. Studies were conducted as early as 1972 and as recently as 2015. Many studies included data collected from the 1980s or 90s. The most commonly studied CA was congenital heart defect (CHD) -18 studies, followed by 10 studies examining chromosomal anomalies and an additional 9 examining Down Syndrome. Eight studies looked at Neural Tube Defects (NTDs). The table below is excerpt of the data extraction file.
Limitations: Studies did not consistently cover time periods over the same populations over all states in the U.S., therefore comparisons are not reliable. Pregnancies with a CA are likely to be referred to a hospital in a city-center for specialized care, inaccessible to some groups. Several states regularly report results from analyses of state birth defect registries, while other studies were hospital-based or focused on specific CAs.
Termination rates by anomaly • Termination rates ranged from 2% (heterotaxy: CHD) to 94% (chromosomal) • Pregnancies afflicted with chromosomal anomalies, and DS in particular, had the highest rates of termination (See Table 2)
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Research questions
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What is the termination rate for different types of congenital anomalies (CA) since 1995?
Implications:
Factors contributing to terminations •
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In one study younger mothers of low SES were more likely to continue a pregnancy afflicted with a CA Several studies revealed that white parents were more likely to terminate than black (e.g.,Velie and Shaw, 1996) Studies based in Texas, close to the Mexico border, found that women of Hispanic decent were less likely to terminate for an anomaly. Pregnancies that were afflicted with chromosomal anomalies in addition to other structural anomalies (e.g., cleft lip, CHD, lung lesions) were more likely to be terminated
What factors impact a mother’s decision to terminate for CA? How have termination rates changed over time?
We systematically reviewed several health databases to identify studies that would include abortion rates for congenital anomalies. We employed the following search strategy: (birth defects or congenital defects or genetic defects or fetal abnormal*) AND (termination of pregnancy or abortion). We limited all results to studies published from 1995-2016 and only included English language articles based on samples in the United states. See Table 1 for the search process. We then extracted relevant data in order to make generalization about the studies we reviewed.
Pregnant women and prenatal diagnosis
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Table 3 reports termination rates over time for CHD. No discernable pattern emerges. Termination decisions tend to be dependent on severity, lethality, specific anomaly within a category (e.g., type of CHD), and whether or not there are also chromosomal abnormalities.
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Most of the research reviewed for the review highlighted the importance of prenatal diagnosis and therefore testing, so that families can make informed decisions early in the pregnancy.
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Any increase in rates may be due to improved and earlier prenatal diagnoses as technology improves Table 3
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In states were the termination limit is 24 early diagnosis is essential for families wishing to terminate a pregnancy. Further early diagnosis, can lead to earlier terminations that are safer and possibly less traumatic.
Table 2
range
1990-2004
1992-1999
Table 1
1993-2006 1995-2008
Identification:
1995-2011 1998-2006
CINAHL (358)
Embase (103)
Maternity & Infant Care (233)
PubMed (3992)
Psych INFO (60)
Science Direct (76)
2001-2002 2001-2003
2002-2004
2002-2004
2003-2008
5,887 records identified
Screening :
3,621 non U.S. studies removed
v 2, 266 records screened on titles and abstracts
Eligibility: 150 full text articles retrieved
79 Records included in the systematic review
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Records excluded from full text due to irrelevance, non-U.S. study, no Termination rates, single patient case study, duplicates, focus on grieving
Types of counseling offered to women in different contexts (nondirective, psychological, evidence-based) Consequences of the prevalence of terminations for certain defects: lack of resources, education and support for those afflicted with those anomalies.
Studies report disparate time ranges, however, some trends can be identified. Although rates appear to increase overtime, comparisons of rates across anomalies are not reliable.
1993-1999
Health Source: Academic (151)
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Methods
Academic Search Complete (914)
Public health
Termination rates over time
Which CA are more likely to be terminated and why?
The two most common birth defects
CA Sample size # term. CHD isomerism (CHD) 166 CHD DandyWalker and variants 99
% term.
20
12%
54
55%
CHD CHD cardiac malposition CHD: singleventrical CHD heterotaxy
408
98
24%
101
5
4%
312
98
31%
154
3
2%
CHD CHD translocation of the great arteries CHD CHD atrioventricul ar septal defect CHD double right ventricle CHD: Tetralogy of Fallot CHD Ebstein's anomoly
252
14
6%
70 98
19 49
27% 50%
20
4
20%
19
3
16%
35
15
43%
243
15
6%
2010 CHD
138
94
68%
2013 CHD HLHS
240
24
10%
2005-2011
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For families wishing to continue a pregnancy diagnosed with a CA, early diagnosis can allow parents to prepare for treatment, potential disability, or early death.
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Certain types of prenatal diagnoses are less invasive than amniocentesis and may provide more accurate diagnoses. Women with risk factors for CA should be aware of the different types of prenatal testing available to them.
Trisomy 21 AKA Down Syndrome
Congenital Heart Defects This is an image of fetal heart showing hypoplastic left heart syndrome