Studies - PreTerm Delivery / Premature Birth / Prematurity Complications

BMJ: Induced Abortion Increases Risk in Future Pregnancies (2/2001)


Editor – The latest of three Danish reports about reproductive history informs readers that "fetal loss is high in women in their late 30s or older, irrespective of reproductive history. This should be taken into consideration in pregnancy planning and counselling." [1]

Consider a woman whose first pregnancy occurs at age 30. According to Melbye et al and Zhou et al, if she is pressured to have an induced abortion she should be warned that if she does so she will increase her risk of never having a birth. [2] [3] Will the abortion clinic tell her that her best chance for a full term birth is to carry her current pregnancy to term? No, it will not; no abortion clinic's consent form mentions such a risk.

Even if the woman does have a future birth, a previous induced abortion roughly doubles the risk that it will be very preterm (less than 34 weeks' gestation), according to another study of Danish women (relative risk 1.99 (95% confidence interval 1.64 to 2.43)). [3] If the woman has two evacuation-type abortions she increases her risk of preterm birth by 1155% (5.14 to 30.64). [3] There are at least nine other reports that found an increased risk of prematurity from previous induced abortions [4] [5] (readers can visit for references to 10 studies known to me).

By not informing prospective patients of health risks associated with induced abortion, abortion doctors are violating their legal duty to protect health and not needlessly endanger it. Is there any serious health risk for a mother who has a preterm birth? In their study of Danish women Melbye et al inform us that if the gestation of a newborn infant is under 32 weeks the mother has doubled her risk of breast cancer compared with having a full term birth (relative risk 2.08 (1.20 to 3.60) for gestation of 29-31 weeks). [2]

Let us ensure that women of reproductive age are fully informed about health risks of medical treatments to them and their future children.

[British Medical Journal February 17, 2001 Author: Brent Rooney, Posted on 05/30/2001] 

Brent Rooney, independent medical researcher.
Reduce Preterm Risk Coalition, 3456 Dunbar St (146), Vancouver , Canada V6S 2C2 [email protected]

1. Nybo Andersen A-M, Wohlfahrt J, Christens P, Olsen J, Melbye M. Maternal age and fetal loss: population based register linkage study. BMJ 2000; 320: 1708-1712. (24 June.)
2. Melbye M, Wohlfahrt J, Andersen A-MN, Westergaard T, Andersen PK. Preterm delivery and risk of breast cancer. Br J Cancer 1999; 80: 609-613.
3. Zhou W, Sorenson HT, Olsen H. Induced abortion and subsequent pregnancy duration. Obstet Gynecol 1999; 94: 948-953.
4. Lieberman E, Ryan KJ, Monson RR, Schoenbaum SC. Risk factors accounting for racial differences in the rate of premature birth. N Engl J Med 1987; 317: 743-748.
5. Berkowitz GS. An epidemiologic study of preterm delivery. Am J Epidemiol 1981; 113: 81-92.