http://humupd.oxfordjournals.org/content/early/2015/09/19/humupd.dmv041.full.pdf+html
Title: Health Disparities in risk for cervical insufficiency
Journal: Human Reproduction Advance Access
doi:10.1093/humrep/deq177
Authors: Emmanuel A. Anum, Haywood L. Brown, & Jerome F. Strauss III
URL: http://humrep.oxfordjournals.org/cgi/reprint/deq177v1
( click on ‘begin manual download’ )
Date: 19 July 2010
Excerpts from the Abstract:
Results: Cervical insufficiency risk for Black women was more than twice that for their White counterparts [odds ratio (OR) (95% confidence interval (CI) of 2.45 (2.22-2.71)].
Prior pregnancy termination showed a dose-response with cervical insufficiency.
Compared to women with no history of prior pregnancy termination, primiparous women who had one pregnancy termination had an OR (95% CI) of 2.49 (2.23-2.77).
The OR for two, three and four or more terminations were 4.66 (4.07-5.33), 8.07 (6.77-9.61) and 12.36 (10.19-15.00) respectively.
Other predictors of cervical insufficiency included previous preterm birth, parity, marital status, renal disease, history of diabetes, polyhydramnios and anemia.
Conclusions: There were significant racial/ethnic disparities with Black women having increased cervical insufficiency risk, independent of other studied factors.
Prior pregnancy termination is also a major risk factor for cervical insufficiency. The White/Black disparity is evident in both primiparous and multiparous women.
………………………………………………………………………………………………….
Pregnancy termination showed a strong association with cervical insufficiency, with the risk increasing as the number of previous pregnancy terminations increases.
Compared with women with no history of prior pregnancy termination, primiparous women who have had one pregnancy termination:
IAs 1 2 3 4+
O.R. 2.49 4.66 8.07 12.36
95% CI (2.23-2.77) (4.07-5.33) (6.77-9.61) (10.19-15.00)
Introduction excerpts
Surgical and medical treatments such as cervical biopsy, treatment for cervical cancer, routine dilation and curettage for diagnostic and therapeutic purposes and termination of pregnancy, and trauma may all result in structural damage to the cervix, which may lead to cervical insufficiency.
Forceful dilatation of the cervix performed during surgical procedures, and termination of pregnancy has the potential to damage the endocervix and result in cervical insufficiency, (Grunberger and Riss, 1979) and subsequent preterm delivery.
The length of the cervix is an important risk factor in preterm delivery evaluation (Petrovic et al., 2008) and the damage that repeated terminations may cause to the cervix includes shortening of the cervix.
A short cervical length is a strong predictor of spontaneous preterm birth (Iams et al., 1996; Goldenberg et al., 2008).
In a study among women with multiple prior-induced abortions, Visintine et al. (2008) reported preterm birth incidence of 47% in women with a short cervix (cervical length, 25 mm) compared with 14% among those without a short cervix…
Although the association between cervical insufficiency and preterm birth is well established, no study has at yet examined cervical insufficiency rates and risk by race.
Blacks have a higher preterm birth rate compared with Whites, and since having a preterm delivery is in itself a risk factor for cervical insufficiency, this study examined cervical insufficiency among primiparous women to determine if there are ethnic and racial differences in cervical insufficiency risk…
Results
… All racial groups had some fraction of their population with a history of at least one previous pregnancy termination.
Blacks, however, had a significantly greater proportion of their population with two or more pregnancy terminations…
Discussion
The strong association between prior pregnancy termination and cervical insufficiency irrespective of race/ethnicity was confirmed in our analysis…
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[November 2015 Comments: Apparently, the 1989 version of the US standard birth certificate included data on number of pregnancy terminations. Even since 2003 (when many states revised their forms so as not to include cervical incompetency–an interesting fact in and of itself), 69% of all live births have these data.
So this gives a representative sample (essentially a 2004 snapshot) of all singleton births in 69% of the US births.
Moreover, this study provides hard data on how many women in the US populations have had abortions: About 17% (combined all ethnicities) of women age about 24 who deliver a child, have had one or more induced abortions. That’s about one in 6, or only about half of what Planned Parenthood estimates.
And since the proper birth certificate form goes back to 1989, there should be plenty of women in breast cancer registries to link up with this database.
Moreover, they include a link to the CDC user guide for this natality database, i.e., “User Guide to the 2005 Natality Public Use File”: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Dataset_Documentation/DVS/natality/UserGuide2005.pdf
This paper was not discovered for 5 years because it lacked proper key words: The terms “prematurity”, “pre-term birth” and related terms were not among the key words; only “cervical insufficiency”.]
http://humrep.oxfordjournals.org/content/early/2010/07/19/humrep.deq177.full.pdf+html