Elective medical procedure boosts risk of Cerebral Palsy

by Brent Rooney
independent medical researcher
Vancouver, Canada

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In February 2001 the British Medical Journal published my letter identifying an elective medical procedure that elevates a woman's risk of subsequent preterm birth; at the time I wrote the letter I was aware of ten studies finding significantly increased risk.35 My current count is twenty-seven (27).1-25,37,38 Patients and medical doctors both benefit if the "prudent practice of medicine" produces results that render the desire to resort to malpractice law suits extremely unlikely. Very specifically, gynecologists must seriously consider "abstaining" from any elective medical procedure with credible odds of increasing a woman's risk of a subsequent preterm birth. Consider just one malady that preterm birth renders more likely: Cerebral Palsy.29 In Britain there was "a threefold rise in litigation for negligence leading to brain damage to infants between 1984 and 1989, and that the average award had increased almost threefold in a similar period."30 If the birth is so preterm that the birth weight falls below 1500 grams, the risk of cerebral palsy is approximately thirty-eight times that of a full-term normal weight newborn infant.32 Is there an elective procedure with a credible prematurity risk?

If there was one statistically significant report in a peer reviewed medical journal finding that an elective medical treatment raised the risk of a subsequent preterm birth, then women must be warned of this possible risk. There are, at least, twenty-seven studies in peer reviewed medical journals finding (with statistical significance) that previous induced abortions increase the risk of a subsequent preterm birth; twenty-seven exceeds 1 by 2,600 percent. How many have reported a statistically significant reduction in preterm birth risk via previous induced abortions? None, to your author's knowledge. By themselves, these twenty-seven reports certainly make the induced abortion/prematurity risk a more than merely credible one and one that legally must be included on consent forms, at least at the level of "possible risk". The rest of this article will present arguments that will convince "objective gynecologists" that the purported risk has very high credibility.

Three world renowned experts find elevated PB risk

What if three world renowned preterm birth experts identified an elective medical procedure as boosting subsequent preterm birth risk? Would that make the risk very plausible? The only answer to that question can only be "YES". The three renowned experts:

  1. Barbara Luke (ScD, MPH; Dept. of Obstetrics and Gynecology, University of Michigan)
  2. Judith Lumley (PhD; Centre for the Study of Mothers' and Children's Health, Victoria, Australia)
  3. Emile Papiernik (MD, Professor of Obstetrics and Gynecology, Maternite Port Royal)

Professor Barbara Luke in her classic book wrote, "If you have had one or more induced abortions, your risk of prematurity with this pregnancy increases by about 30 percent." (Every Pregnant Woman's Guide to Preventing Premature Birth, 1995) In that same book Luke identifies both previous spontaneous abortions and previous induced abortions as risk factors for later preterm births. Judith Lumley in 1998 reported both as risk factors with induced abortions having approximately the same prematurity risk as spontaneous abortions.10 How credible is Luke's 1995 book? "This complete and accurate book should have great appeal to the discriminating woman who is pregnant or planning pregnancy, as a means of maximizing her chances for a successful pregnancy." So wrote the editor of the medical journal Obstetrics & Gynecology, Roy M. Pitkin (M.D.).28

Who is Emile Papiernik? Dr. Papiernik was director of a national program in France that lowered the prematurity rate by 31.5 percent in its first ten years!! Compare this magnificent accomplishment with the U.S. situation where the prematurity rate has risen steadily over the last 20 years and is now approximately 11%. In 1999 Papiernik, et al., reported:

  1. 86% increased risk of very preterm birth (less than 33 weeks' gestation) for women with previous first trimester abortions
  2. 267% increased risk of very preterm birth for women with previous second trimester abortions19

So what, if induced abortions boost preterm birth risk?

Preterm birth (under 37 week's gestation) is universally recognized as the number one cause of infant death before age one year. Those "preemies" who do not die are at much higher risk for physical and mental handicaps. One such handicap is cerebral palsy.29 Is it biologically plausible that abortions can increase the risk of a subsequent preterm birth?

Highly regarded obstetric expert, Barbara Luke, has identified one mechanism that explains why abortion raises prematurity risk. "The procedures for first-trimester abortion involve dilating the cervix slightly and suctioning the contents of the uterus (see Figure 3). The procedures for second-trimester abortion are more involved, including dilating the cervix wider and for longer periods, and scraping the inside of the uterus. Women who had had several second-trimester abortions may have a higher incidence of incompetent cervix, a premature spontaneous dilation of the cervix, because the cervix has been artificially dilated several times before this pregnancy."28 Is there a second biological risk that helps to explain higher prematurity risk? Yes, infection risk. "Our findings indicate that an abortion in a woman's first pregnancy does not have the same protective effect of lowering the risk for intrapartum infection in the following pregnancy as does a live birth." So wrote researchers (1996) from the University of Washington in the respected medical journal Epidemiology.26 Infection is a leading cause of death from induced abortion (if one ignores breast cancer and suicide from abortion). Infection is often mentioned as a risk factor for premature birth. In 1992 Dr. Janet Daling and colleagues reported that if the previous pregnancy ended in induced abortion, the risk of intraamniotic infection [i.e. infection of the amniotic sac] increased by 140% (95% CI=1.7-3.4).27 "One possible mechanism is that cervical instrumentation can facilitate the passage of organisms into the upper part of the uterus, increasing the probability of inapparent infection and subsequent preterm birth", wrote Australian researcher Judith Lumley in 1998.10

The PB risk in brief

Most abortion clinic consent forms list infection as a risk and some list "incompetent cervix" (e.g. "lacerated cervix") but NO form lists a very serious consequence of these risks: elevated risk of a future preterm birth. In brief what makes the abortion/preterm birth risk very credible is:

  1. Three world experts (Luke, Lumley, Papiernik) report that induced abortion boosts prematurity risk
  2. ONE HUNDRED percent of TWENTY-SEVEN statistically significant medical studies find higher prematurity risk
  3. Dose/response - most of the studies that looked for it, found that the more the number of previous induced abortions, the higher the prematurity risk. 1,2,3,7,8,10,15,16,17,18,19,20,37,38 Two evacuation abortions increases prematurity risk by 1155% (95% CI 5.14-30.64).1
  4. Biological Plausibility - incompetent cervix and infection are risks of induced abortion and risks for preterm birth.10,26,27,28,33
  5. Consent forms list infection and/or incompetent cervix as risk factors of induced abortion
  6. In 1967 in Eugenics Review Dr. Malcolm Potts conceded that induced abortion increased prematurity risk.36 "there seems little doubt that there is a true relationship between the high incidence of therapeutic abortion and prematurity. The interruption of pregnancy in the young (under seventeen) is more dangerous than in other cases."36 "Birth before 32 weeks [gestation] is ten times more likely with the diagnosis of incompetent cervix", wrote Professor Barbara Luke.28 Since black American women have about triple the rate of induced abortion as Caucasian women, this helps to explain their tripled risk of very preterm birth relative to Caucasian women.34,35


A medical doctor has a legal duty to protect a woman patient's health. To severely threaten a woman's reproductive health is a direct and potentially expensive violation of this duty. Defenders of "terminations" will trot out the old "Joe Camel" defense of "not conclusively proven" and thus, no warning of risk should be given. Only one report in a peer reviewed medical journal finding increased prematurity risk from previous induced abortions need be provided for a warning of possible preterm birth to be issued. TWENTY-SEVEN reports is 2600 percent more than one report. The warning was a must in 1980, not to mention 2001. To protect themselves from potentially huge legal liabilities, medical doctors should refrain from performing elective (!) induced abortions.

Final Words belong to a Pediatrician

In a 'recent' (1998) book pediatrician Dr. Elliot Gersh included the following risk factor for cerebral palsy:

"Incompetent cervix (premature dilation) leading to premature delivery" 29 Incompetent cervix is a known risk of induced abortion surgery.28,33


  1. Zhou W, Sorenson HT, Olsen H. Induced Abortion and Subsequent Pregnancy Duration. Obstetrics & Gynecology 1999;94:948-953
  2. Berkowitz GS. An Epidemiologic Study of Preterm Delivery. American J Epidemiology 1981;113:81-92
  3. Lang JM, Lieberman E, Cohen A. A Comparison of Risk Factors for Preterm Labor and Term Small-for-Gestational-Age Birth. Epidemiology 1996;7:369-376
  4. Lieberman E, Ryan KJ, Monson RR, Schoenbaum SC. Risk Factors Accounting For Racial Differences in the rate of premature birth. NEJM 1987;317:743-748
  5. * Hillier SL, Nugent RP, Eschenbach DA, Krohn MA, et al. Association Between Bacterial Vaginosis And Preterm Delivery Of A Low-Birth-Weight Infant. NEJM 1995;333:1737-1742
  6. Schoenbaum LS, Monson RR. No association between coffee consumption and adverse outcomes of pregnancy. NEJM 1982;306:141-145
  7. Mueller-Heubach E, Guzick DS. Evaluation of risk scoring in a preterm birth prevention study of indigent patients. Am J Obstetrics & Gyn 1989;160:829-837
  8. Shiono PH, Lebanoff MA. Ethnic Differences and Very Preterm Delivery. Am J Public Health 1986;76:1317-1321
  9. Pantelakis SN, Papadimitriou GC, Doxiadis SA. Influence of induced and spontaneous abortions on the outcome of subsequent pregnancies. Amer J Obstet Gynecol. 1973;116:799-805
  10. Lumley J. The association between prior spontaneous abortion, prior induced abortion and preterm birth in first singleton births. Prenat Neonat Med 1998;3:21-24.
  11. Van Der Slikke JW, Treffers PE. Influence of induced abortion on gestational duration in subsequent pregnancies. BMJ 1978;1:270-272 [>95% confident of preterm risk for gestation less than 32 weeks]
  12. Richardson JA, Dixon G. Effect of legal termination on subsequent pregnancy. British Med J 1976;1:1303-1304
  13. Pickering RM, Deeks JJ. Risks of Delivery during 20th to the 36th Week of Gestation. Intl. J Epidemiology 1991;20:456-466
  14. Koller O, Eikhom SN. Late Sequelae of Induced Abortion in Primigravidae. Acta Obstet Gynecol Scand 1977;56:311-317
  15. Papaevangelou G, Vrettos AS, Papadatos D, Alexiou C. The Effect of Spontaneous and Induced Abortion on Prematurity and Birthweight. The J Obstetrics and Gynaecology of the British Commonwealth. May 1973;80:418-422
  16. Bognar Z, Czeizel A. Mortality and Morbidity Associated with Legal Abortions in Hungary, 1960-1973. AJPH 1976;66:568-575
  17. Martius JA, Steck T, Oehler MK, Wulf K-H. Risk factors associated with preterm (<37+0 weeks) and early preterm (<32+0 weeks): univariate and multi- variate analysis of 106 345 singleton births from 1994 statewide perinatal survey of Bavaira. European J Obstetrics & Gynecology Reproductive Biology 1998;80:183-189
  18. Vasso L-K, Chryssa T-B, Golding J. Previous obstetric history and subsequent preterm delivery in Greece. European J Obstetrics & Gynecology Reproductive Biology 1990;37:99-109
  19. * Ancel P-V, Saurel-Cubizolles M-J, Renzo GCD, Papiernik E, Breart G. Very and moderate preterm births: are the risk factors different? British J Obstetrics and Gynaecology 1999;106:1162-1170
  20. Lumley J. The epidemiology of preterm birth. Bailliere's Clin Obstet Gynecology. 1993;7(3):477-498
  21. * Michielutte R, Ernest JM, Moore ML, Meis PJ, Sharp PC, Wells HB, Buescher PA. A Comparison of Risk Assessment Models for Term and Preterm Low Birthweight. Preventive Medicine 1992;21:98-109
  22. Grindel B, Lubinski H, Voigt M. Induced abortion in primigravidae and subsequent pregnancy, with particular attention of underweight. Zentralbl Gynaekol 1979;101:1009-1114
  23. Kreibich H, Ludwig A. Early and late complications of abortion in juvenile primigravidae (including recommended measures). Z Aerztl Fortbild (Jena) 1980;74:311-316
  24. Zwahr C, Voigt M, Kunz L, et al. Relationships between interruption abortion, and premature birth and low birth weight. Zentrabl Gynaekol 1980;102: 738-747
  25. Pickering RM, Forbes J. Risk of preterm delivery and small-for-gestational age infants following abortion: a population study. British J Obstetrics and Gynecology 1985;92:1106-1112
  26. Muhlemann K, Germain M, Krohn M. Does an Abortion Increase the Risk of Intrapartum Infection in the Following Pregnancy? Epidemiology 1996;7:194-198
  27. Daling JR, Krohn MA, Miscarriage or Termination in the Immediately Preceding Pregnancy Increases the Risk of Intraamniotic Infection in the Following Pregnancy. American J Epi 1992;136:1013 [SER Abstracts]
  28. Prof. Barbara Luke. Every Pregnant Woman's Guide to Preventing Premature Birth (1995) [forward by Emile Papiernik], New York: Times Books
  29. Gersh ES. Children with Cerebral Palsy 1998; chapter 1:page 14; DD: 618.92836 C53G1, ISBN: 0933149824
  30. Paroah POD. Cerebral Palsy and perinatal care. British J Obstetrics Gynaecology 1995;102:356-358
  31. Pediatrics 1985;76:154-158
  32. Escobar GJ, Littenberg B, Petitti DB. Outcome among surviving very low birthweight infants; a meta-analysis. Arch Dis Child 1991;66:204-211
  33. Wright CSW, Campbell S, Beazley J. Second-Trimester Abortion After Vaginal Termination Of Pregnancy. Lancet 1972 [June 10]:1278-1279
  34. Rooney B. Racism, Poverty, Abortion, and Other Reproductive Outcomes. Epidemiology 2000;11:740-741
  35. Rooney B. Having an induced abortion increases risk in future pregnancies. British Medical J 2001;322:430
  36. Potts M. Legal Abortion in Eastern Europe. enics Review7;59:232-250
  37. Obel E, et al. Pregnancy Complications Following Lgally Induced Abortion With Special Reference to Abortion Technique. a Obstet Gynecol Scand 1979;58:147-152
  38. Levin A, Schoenbaum S, Monson R, Stubblefield P, Ryan K. Association of Abortion With Subsequent Pregnancy Loss. JAMA 1980;243(24):2495-2499

* - studies that recorded both induced and spontaneous abortions and did not analyze them separately.

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Posted 19 Jun 2001.

Copyright 2001 by Brent Rooney.
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