Introduction We studied perinatal health of first born children by mother's abortion history in Finland with good abortion and birth services and relatively few abortions.

Methods Nationwide registers covering all births and induced abortions were used. All first time mothers in Birth Register (1996–2008) were linked to Abortion Register (1983–2008). The perinatal health of children was compared by the number of mother's abortions adjusting by logistic regression for mothers' age, civil status, socioeconomic status, urbanity and smoking.

Results Of the 300 858 mothers, 22 860 (7.6%) had one, 2681 (0.9%) two, 542 (0.2%) three or more abortions. Of abortions, 88% were surgical, 91% were made <12 weeks, and most were made for social reasons. Compared to mothers with no previous abortion, perinatal health problems (preterm birth, low birth weight, low Apgar score 0–6, perinatal death) were not more common among mothers having had one abortion, but were among mothers having had 3+ abortions. Results on preterm birth (adjusted OR for <28 weeks 2.41 and for <37 weeks 1.34) and on low birth weight (<1500 g 1.92, <2500 g 1.42) were statistically significant. Among women having two previous abortions very preterm (<28 weeks, OR 1.45) and low Apgar scores (OR 1.10) were increased, but not statistically significantly.

Conclusions One previous abortion did not increase perinatal problems at first birth, but three or more did; two were in between. This may be due to mothers' characteristics not controlled for or due to sequel of repeated abortions.