Studies - PreTerm Delivery / Premature Birth / Prematurity Complications

Another Journal Study Links Multiple Abortions and Preterm Birth (HR, 2012)

2012 Human Reproduction Journal Study Links Multiple Abortions and Preterm Birth

A new study has found that women who undergo multiple abortions have an increased risk of preterm birth in a subsequent pregnancy. According to a report:

    A new study released from Finland’s National Institute for Health and Welfare finds women who have multiple abortions have a greater risk of premature birth and low-birth weight babies in subsequent pregnancies.

    The study, printed in the peer-reviewed medical journal Human Reproduction, of more than 300,000 women found women who have three or more abortions face a 35 percent increase in health complications in a future pregnancy and also saw an increase in the risk of a baby’s death around the time of birth.

    Having just one abortion or more increased the likelihood of giving birth before reaching 37 weeks of pregnancy.

    “To put these risks into perspective, for every 1,000 women, three who have had no abortion will have a baby born under 28 weeks,” Dr Reija Klemetti, who led the study, told the Scotsman newspaper. “This rises to four women among those who have had one abortion, six women who have had two abortions, and 11 women who have had three or more.”

Other new research has found that women who undergo multiple abortions have an increased risk of death.

The study, which examined medical records for all women of reproductive age in Denmark over a 25 year period, found that a single induced abortion increases the risk of maternal death by 45 percent compared to women with no history of abortion.

In addition, each additional abortion is associated with an even higher death rate.

Women who had two abortions were 114 percent more likely to die during the period examined, and women had three or more abortions had a 192 percent increased risk of death.

Other Research Links Abortion and Preterm Birth

The Finland study is not the first to find a higher rate of preterm birth and other problems in pregnancies following abortion. In a paper published in the British Journal of Obstetrics and Gynaecology in 2009, a Canadian research team examined data from 37 studies and found that having a prior abortion increased the risk of subsequent preterm birth by 36 percent, while having more than one prior abortion increased the risk by 93 percent.1 (Preterm birth is defined as a birth that takes place before 37 weeks gestation.)

In other words, children whose mothers had a previous abortion were more likely to be born prematurely, putting them at greater risk for problems such as low-birth weight (which has been linked to physical and developmental problems), epilepsy, autism, mental retardation2 and cerebral palsy. A research team looking at data from 2002 estimated that prior abortions led to 1,096 cases of cerebral palsy among babies born prematurely that year.3

More recently, Harvard University researchers tracking a group of more than 116,000 nurses reported in 2011 that the women in the study who had one or more abortions prior to their first delivery had a 26 percent higher chance of having a child with autism.4

Brent Rooney, Director of Research for the Reduce Preterm Birth Coalition, writes:

    Is it biologically plausible that prior maternal induced abortions elevate a newborn baby’s autism risk? In a word, yes.

This is because of two mechanisms — preterm birth (very preterm and extremely preterm) and raised parental age at delivery. Six significant studies report that prior induced abortions boost extremely preterm birth risk (under 28 weeks’ gestation).

    Extremely preterm babies have about 25 times the autism risk as do full-term (at least 37 weeks’ gestation) babies.5

The older the parents are at delivery, the higher the autism risk.

In a 2001 study of French women, Dr. Henriet reported that French women with more than one prior induced abortion had 2.4 times (i.e. 140 percent higher) the risk of maternal age over 34 at delivery compared to women with zero prior induced abortions.6

There are risks to the mother with preterm birth as well, as other studies have found that women who give birth at less than 32 weeks double their lifetime risk of breast cancer.7

Evidence of Risk Continues to Grow

Evidence linking abortion and preterm birth continues to pile up, researchers and advocates say. Another paper published in 2009 found that having a previous abortion raised a woman’s relative odds of having a subsequent birth at less than 32 weeks by 64 percent.8

Further, as far back as 2006, the Institute of Medicine included “prior first trimester abortion” on a list of risk factors associated with premature birth.9

However, as Rooney has pointed out, abortions continue to be performed despite the strong evidence of risks—and in the absence of any evidence showing the procedure to be harmless.

Rooney noted that “in the ‘Court of Medicine’ a ‘defendant’ new surgery or new drug is presumed guilty of serious adverse side effects until by strong evidence it is demonstrated to be innocent.” Yet 50 years after the development of the suction abortion procedure, he said, there has never been a “study of studies or systematic review” that has proven that abortion does not cause premature birth.

Instead, the evidence seems to be pointing in the opposite direction.


Learn more: Access the world’s most extensive online library of studies on the physical and psychological effects of abortion at


1. P.S. Shah and J. Zao, “Induced termination of pregnancy and low birthweight and preterm birth: a systematic review and meta-analysis,” BJOG 116(11): 1425-1442 (2009).

2. Barbara Kay, “The abortion issue we’re ignoring,” National Post, June 10, 2009.

3. B.C. Calhoun, E. Shadigan and B. Rooney, “Cost Consequences of Induced Abortion as an Attributable Risk for Preterm Brith and Informed Consent,” Journal of Reproductive Medicine 52(10): 929-937 (2007).

4.K. Lyall et. al., “Pregnancy Complication and obstetric Suboptimality in Children of the Nurses’ Health Study II,” Autism Research 4:1-10 (2011).

5. C. Limperopoulos, “Autism spectrum disorders in survivors of extreme prematurity,” Clin Perinatol 36:791-805 (2009).

6. L. Henriet and M. Kaminski, “Impact of induced abortions on subsequent pregnancy outcome: the 1995 French national perinatal survey,” BJOG 108(10):1036-1042 (2001).

7. M. Melbye et. al., “Preterm Delivery and risk of breast cancer,” British Journal of Cancer, 80(3-4): 609-613 (1999); and K.E. Innes and T.E. Byers, “First pregnancy characteristics and subsequent breast cancer risk among young women,” International Journal of Cancer, 112(2): 306-311


8. H.M. Swingle et. al., ” Abortion and the Risk of Subsequent Preterm Birth: A Systematic Review and Meta-Analysis,” Journal of Reproductive Medicine 54:95-108 (2009).

9. R.E. Behrman et. al., Preterm Birth: Causes, Consequences and Prevention (Washington, D.C., National Academies Press, 2007).


Related: Induced Abortion and Risk of Later Premature Births (2003)