Abortion and Subsequent Pre-term
Birth: Update 2012
Byron C. Calhoun, MD, FACOG, FACS, MBA
Professor and Vice Chair, Obstetrics and Gynecology
West Virginia University-Charleston
Charleston, WV, USA
February, 2012
Disclosure
There are no commercial products
mentioned in this lecture nor is support
being supplied by any vendor, agency, or
governmental grant/agent.
Outline
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I Introduction/Objectives
II. Frequency of PTB
III. Morbidity of PTB
IV. Review important recent studies
V. Latest Studies 2008-2011
VI. US Societal costs of abortion
VII. Future issues in abortion and PTB
I. Frequency & Costs
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Incidence of preterm delivery is 6% year in US
Births average 3-4 million/year in U.S.
Therefore, 180-240,000 births/year in US
The very preterm births (<28 weeks) include
approximately 1% births or 30,000-40,000 births annually
Induced abortion is associated with >$1.2 billion (US) to
health costs annually1
1Calhoun
BC, Shadigian E, Rooney B. Induced abortion: cost consequences of
an attributable risk for preterm birth and its impact on informed consent and
medical malpractice. J Repro Med 2007;52 (10):929-937.
II. Morbidity of Preterm Birth
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Very low-birth (VLBW) weight costs 28 times (RR) term
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Low-birth weight costs 4 times (RR) term
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($280,146 versus $9,803)2,3,4
($38,367 versus $9,393)2,3,4
Cerebral palsy increases by 147 times in VLBW compared
to term (> 37 weeks)5
2Petrou
S, Mehta Z, Hockley C, Cook-Mozaffari P, Henderson J, Goldacre M. Pediatrics
2003;112(6):1290-1297
3Luke
B, Bigger H, Leurgas S, Siesma D. The cost of prematurity: a case-control study of twins vs.
singeltons. AM J Publ Health. 1996;86(6):809-814.
4Infant Health in America:Everybody’s Business. Hartford, CT:CIGNA Corp 2000
5Himpens E, Master PT, Van den Broeck C, Oostra A, Calders P, Vanhaesebrouck P. Prevalence, type,
distribution of cerebral palsy in relation to gestational age: a meta-analysis review. Develop Med &
Child Neuro 2008;50:334-340.
Previous Studies Continued
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Swingle HM, Colaizy TT, Zimmerman MB,
Morriss FH. Abortion and the risk of subsequent
preterm birth: A systematic review with metaanalyses. J Rrepro Med 2009;54:95-108.6
Shah PS, Zao J. Induced termination of pregnancy
and low birthweight and preterm birth: a
systematic review and meta-analysis. BJOG
2009;116:1425-1442.7
Meta-analysis by Swingle, et al
2009.6
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Meta-analyses of literature 1995-2007
Pro-abortion & pro-life authors
7,891 titles, 349 abstracts, 130 papers
30 abortion & 26 SAB papers included
Analyzed data from 12 induced and 9 SAB papers
Demonstrated 64% increased risk with single
abortion for very preterm birth < 32 weeks
Meta-analysis by Swingle, et al
2009.8
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12 studies used to calculate common OR’s
for induced abortion
1 induced abortion 1.25 OR [1.03-1.48]
increased risk preterm birth < 37 weeks
> 1 induced abortion 1.51 OR [1.21-1.75]
increased risk preterm birth < 37 weeks
Meta-analysis by Swingle, et al
2009.6
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4 studies available for common OR’s for
induced abortion < 32 weeks
Common OR 1.64 [1.38-1.91]
Increased very preterm delivery rate of 64%
Similar to other literature’s findings
Meta-analysis by Swingle, et al
2009.6
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7/12 studies available for common OR with
SAB’s for preterm delivery < 37 weeks
1 SAB 1.43 OR [1.05-1.66]
> 1 SAB 2.27 OR [1.98-2.81]
Meta-analysis by Shah, et al 20097
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Screened 834 papers
Excluded 765 for lack data/objective
69 citations retrieved
32 excluded
Meta-analysis by Shah, et al 20097:
32 excluded studies
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Exclusions
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7 studies no neonatal outcomes
7 reported combined SAB/abortions
5 no comparison group
4 reports reviews
3 reported VLBW and LBW only
2 studies specific population only
2 studies previously published data
1 duplication publication
1data not available
Meta-analysis by Shah, et al 20097:
37 included studies
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18 studies with Low Birth Weight (LBW)
22 studies for preterm birth (PTB)
3 studies for small for gestationaal age
(SGA
Meta-analysis by Shah, et al 20097:
18 LBW Studies
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No abortion vs 1 TAB
18 studies
280,529 patients
OR 1.35 [1.20-1.52]
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No abortions vs > 1
5 studies of 18
49,347 patients
1.72 [1.45-2.04]
Meta-analysis by Shah, et al 20097:
22 PTB Studies
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No abortion vs 1 TAB
22 studies
268,379 patients
OR 1.36 [1.24-1.50]
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No abortions vs > 1
7 studies of 22
158,421 patients
1.93 [1.38-2.71]
Meta-analysis by Shah, et al 20097:
3 SGA Studies
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No abortion vs 1 TAB
3 studies
38,835 patients
OR 0.87 [0.69-1.09]
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No abortions vs > 1
2 studies of 3
35,422 patients
1.06 [0.84-1.33]
2011: another busy year for preterm birth
and abortion studies (now 127 studies)
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3 new interesting studies on preterm birth
and abortion8-10
1 data based linked8
2 cohort studies9-10
Di Renzo, et
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Multicenter, observational, retrospective and
cross-sectional study in 9 centers in Italy
Records linked to outcomes
Power analysis done prior found needed 6,000
women to determine a difference in preterm birth
(baseline PTB rate 5%)
Sample included 7,634 women (SeptemberDecember 2008)
Di Renzo, et
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15 variables evaluated as co-factors
Included BMI, age, medical comorbidities,
tobacco abuse, previous cesarean section,
and abortion
Did not separate out when abortions
occurred or numbers of abortions
Multivariate analysis
Di Renzo, et
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OR increased risk preterm birth 1.954
(1.162-3.285) with previous abortion
Also found in the study increased risk with:
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BMI >25 OR 1.662 (1.033-2.676)
Previous cesarean OR 2.904 (1.66-7.910)
Di Renzo, et
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Conclusions:
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Positives
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Large, linked data base with power/multivariate
analysis
Found increased PTB risk in ALL patients with
previous abortions as separate factor
Negatives
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Did not separate out abortion timing
Did not do analysis for multiple abortions
Liao, et
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Cohort study
4 years from January 2006-December 2009
Interview based with delivery outcomes
18,323 women (19,527 interviewed)
(93.8%)
Liao, et
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Divided into 3 comparison groups:
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Nulliparous women with 1 or more first
trimester medical abortions (mefepristone)
Nulliparous with surgical abortions (elective)
Nulliparous with no previous abortions
Liao, et
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7,478 with complete follow up in abortion
group out of original 7,558 (98.9%)
10,546 with complete follow up in no
abortion group out of original 10,681
(98.9%)
Liao, et
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In no abortion group there were 332
spontaneous abortions 332/10,546 or 3.15%
In the abortion group there were:
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1,769 one medical abortion 1,769/7,468(24%)
2,900 one surgical abortion 2,900/7,468(38%)
553 >1 medical abortion 553/7,468(7.4%)
1,088 >1 surgical abortion 1,088/7,468(15%)
1,168 with medical/surgical 1,168/7,468 (16%)
Liao, et
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OR 1.4 (1.1-1.8) preterm birth with 1
surgical abortion
OR 1.62 (1.27-3.42) preterm birth > 3
surgical abortions (dose effect)
OR 2.18 (1.51-4.42) preterm birth with
medical & surgical abortions
Liao, et
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OR 1.03 (0.53-1.63) no increase risk of preterm birth with
medical abortions compared to no abortions
However, buried in article found 20.3% of patients needed
a post-abortion suction curettage
OR 1.69 (1.02-3.16) preterm birth risk in women with
medical abortion < 7 weeks with curettage!
AND risk for < 32 week delivery OR was 3.61 (1.43-4.93)
with < 7 week medical abortion with curettage (20% of
patients!)
Did not report either of these findings in abstract
Liao, et
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Conclusions:
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Positives
• Large group of patients (18,323)
• Large number of abortions in several categories
• Found increased risk of PTB with surgical abortions
and combined surgical/medical abortions
Liao, et
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Negatives
• Did not share most startling findings regarding
abortion in this paper
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OR 1.4 (1.1-1.8) preterm birth with 1 surgical
abortion
OR 1.62 (1.27-3.42) preterm birth > 3 surgical
abortions (dose effect)
OR 2.18 (1.51-4.42) preterm birth with medical &
surgical abortions
Liao, et
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Negatives continued
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need for curettage in 20% medical abortions
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OR 1.69 (1.02-3.16) preterm birth risk in women with medical
abortion < 7 weeks with curettage!
AND risk for < 32 week delivery OR was 3.61 (1.43-4.93) with
< 7 week medical abortion with curettage (20% of patients!)
Interview study and not really data linked
Almedia et
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Abstract only in English (Portuguese from
Brazil)
Interview and hospital records
213 live borns < 1500 gms in 2000-2001
Abortion prior to index delivery related to
increased risk for neonatal demise from
preterm birth.
V. Societal Costs of
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Abortion
Child born=$1.4 million (US) benefit to society
Child aborted-$200,000 (US) cost to society
Child born=$200,000 (US) input into treasury
Child aborted=$32,000 (US) cost to treasury
11Finger
R, Harden H. Societal costs of abortion. Focus on Family, Focus on Social Issues,
Worldview and Culture, September 22, 2005.
http://family.org/cforum/fosi/worldview/essays/a0038002.cfm
VI. Future Issues: Liability and
Informed Consent
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Malpractice costs continue to sky-rocket
Median damage award for childbirth:
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>$2 million (US) between 1994-200012
Malpractice premiums ratchet up 30%-50%/year in US
Latest Washington Supreme Court (12/2009) struck
down malpractice caps-opens whole tort problem up
again
R, Oster C. Assigning liability: insurers’ missteps helped
provoke malpractice “crisis”. Wall St J 2002; June 24:A1.
12Zimmerman
Questions regarding Abortion and
Public Health
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Has patient had an abortion prior to incident
pregnancy?
How many abortions did patient have?
• Dose response
Was patient informed of increased PTB risk with
previous abortion? Particularly ethnic risks.
Was patient informed of PTB risk abortion with
cerebral palsy risk?
Abortion and PTB
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Increase awareness of science, risk, costs
Publish papers documenting known risks
Emphasize risk been known for many years
Encourage policy makers to address
Develop strategies to decrease abortions
Conclusions
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Induced abortion increases PTB rates substantially in latest large
studies/meta analyses
Ethnic influence compounds the damage in Blacks
Now 127 studies now with statistical significance (February, 2012)
No studies show decreased risk PTB
PTB increases risk for CP by 147 times
Health/care-neonatal costs increased by over $1.2 Billion (US)
Child aborted-$200,000 (US) cost to society/child aborted-$32,000
(US) cost to treasury
Health care organizations/government need to know costs
Patients ought to be informed of long term health/reproductive risks of
abortion
Abortion counseling ought to include the preterm birth risk particularly
in Blacks and Native Americans.
Questions
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Voice Mail: 304-388-1599
Fax: 304-388-2915
Email: byron.calhoun@camc.org
References
1Calhoun
BC, Shadigian E, Rooney B. Induced abortion: cost consequences of an
attributable risk for preterm birth and its impact on informed consent and
medical malpractice. J Repro Med 2007;52 (10):929-937.
2Petrou S, Mehta Z, Hockley C, Cook-Mozaffari P, Henderson J, Goldacre M.
Pediatrics 2003;112(6):1290-1297
3Luke B, Bigger H, Leurgas S, Siesma D. The cost of prematurity: a case-control
study of twins vs. singeltons. AM J Publ Health. 1996;86(6):809-814.
4Infant Health in America:Everybody’s Business. Hartford, CT:CIGNA Corp
2000
5Himpens E, Master PT, Van den Broeck C, Oostra A, Calders P, Vanhaesebrouck
P. Prevalence, type, distribution of cerebral palsy in relation to gestational age:
a meta-analysis review. Develop Med & Child Neuro 2008;50:334-340.
References
6Swingle
HM, Colaizy TT, Zimmerman MB, Morriss FH. Abortion and
the risk of subsequent preterm birth: A systematic review with metaanalyses. J Rrepro Med 2009;54:95-108.
7Shah PS, Zao J. Induced termination of pregnancy and low birthweight
and preterm birth: a systematic review and meta-analysis. BJOG
2009;116:1425-1442.
References
8Di
Renzo GC, Giardia I, Rosati A, Clerici G, Torricelli M, Petraglia F.
Matnernal risk factors for preterm birth: a country-based population
analysis. Eur J OB/GYN Repro Bio 2011;159:342-346
9Liao H, Weu Q, Duan L, Ge J, Zhou Y, Zeng W. Repeated medical
abortions and the risk of preterm birth in the subsequent pregnancy.
Arch Gynecol Obstet 2011;284:579-586.
References
10Almeda
MF, et al. Survival and risk factors for neonatal mortality in a
cohort of very low birth weight infants in the southern region of Sao
Paulo city, Brazil Cad Saude Publica 2011:;27 (6):1088-1098. (English
abstract only/paper-Portuguese)
11Finger R, Harden H. Societal costs of abortion. Focus on Family, Focus
on Social Issues, Worldview and Culture, September 22, 2005.
http://family.org/cforum/fosi/worldview/essays/a0038002.cfm
12Zimmerman R, Oster C. Assigning liability: insurers’ missteps helped
provoke malpractice “crisis”. Wall St J 2002; June 24:A1.