(Medical Xpress)—Women whose first pregnancy ends in abortion are more at risk of having a premature baby in a second pregnancy than women in their first pregnancy. However, the risk is not as high as that of women who have an initial miscarriage.
The risk does not increase for women who go on to have two or more consecutive terminations.
These are some of the findings of the largest population-based study to date of reproduction outcomes following induced abortion and are based on national data from Scotland, presented today at the British Science Festival.
Surgical rather than medical abortion appears to be associated with the preterm risk, findings which should help guide women and health professionals.
Professor Siladitya Bhattacharya, Chair in Obstetrics and Gynaecology at the University of Aberdeen, led the study which is published in BMJ Open. He said: "Many women start their reproductive life with an abortion in their first pregnancy.
"In 2009, 13,005 abortions were performed in Scotland, with the highest rates in women aged 16 to 19 years. Up until now what has not been entirely clear is the effect these abortions may have on subsequent childbearing. It has been believed that infection, cervical trauma and endometrial curettage associated with induced abortion could lead to future infertility, ectopic pregnancy, preterm delivery and placenta praevia but the data from previous studies have been mixed. One of the key issues is the appropriate comparison group for women with a previous abortion.
"Using anonymised Scottish national data, we compared outcomes in women who had an abortion in their first pregnancy with data for women who either had a live birth or a miscarriage in their first pregnancy and or who were pregnant with their first child.
"We found that women who had an induced abortion in their first pregnancy were more at risk of maternal and perinatal risks in comparison with women who had had a live birth or no previous pregnancy."
Compared with women who had had an initial miscarriage, an abortion in first pregnancy was associated with a higher risk of miscarriage or ectopic pregnancy, another abortion and pre-eclampsia. However women who had had three or four consecutive terminations were not at significantly higher risk of spontaneous premature birth compared with women who had one termination. It was also noted that surgical termination appears to be associated with a higher chance of subsequent pregnancy ending in a preterm delivery.
Professor Bhattacharya added, "The results of this study should help provide women as well as health professionals with accurate information to inform clinical decision-making and tailor antenatal care to address women's risk profiles."
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Professor Silditya Bhattacharya is taking part in a press conference at the British Science Festival today.