Women who experience ectopic pregnancies with their first child are at an increased risk of having another ectopic pregnancy, as well as fewer children during the next 20 to 30 years, than women whose pregnancy finishes with abortion, miscarriage, or delivery. In fact, these women have a 5 times higher chance of another ectopic pregnancy, according to a study published in Human Reproduction.

The new research is the first of its kind to analyze long-term reproductive results in women who had experienced an ectopic pregnancy the first time they were pregnant.

Ectopic pregnancy, also called eccysis, occurs when a fertilized egg implants outside the uterine cavity; it often embeds in one of the fallopian tubes. According to the study, around 1% of pregnancies are ectopic and they never come to full term.

Most of the time, in an etopic pregnancy, the egg dies. Sometimes, methotrexate, a drug which forces the pregnancy tissue to be absorbed into the body, is given to the pregnant woman. In more severe cases, surgery is needed.

Even though experts have determined that a subsequent pregnancy is likely after a previous one, most research conducted on these pregnancies has been limited. The authors say, “We found no controlled study assessing long-term reproductive prognosis in women whose first pregnancy is ectopic.”

For their study, the researchers gathered data from 4 Danish registries for the period between 1977 and 2009. Involved in this data were 2,917 women who, between 1977 and 1982 experienced an ectopic pregnancy when they got pregnant for the first time. All of the women were followed until the end of 2009, or, for a mean time of 23 years, with the exception of the women who died or left the country.

The women involved in the study were paired with other females of the same age whose first pregnancy ended in abortion, miscarriage, or delivery. A fourth group was also compared with the ectopic pregnancy women; those in the fourth group had no pregnancy during the matched year.

Research student from the Gynaecological Clinic at Rigshopitalet in Copenhagen, Denmark, Dr. Line Lund Kårhus (MD), said:

“We found that the group of women who had a first ectopic pregnancy had the lowest delivery rate and total number of pregnancies over the following 20-30 years when compared with the other groups, and also lower rates of miscarriages and abortions. They had a 4.7-10-fold increased risk of further ectopic pregnancies

Women with a first EP had a relative risk of deliveries of 0.55 when compared with women with a first miscarriage; a miscarriage risk of 0.46, a 0.72 risk of induced abortions, and 4.7 times the risk of subsequent EPs. When compared with women with a first induced abortion, the relative delivery rate was 0.89, and with women with no pregnancy 0.69.

Among women who had a first ectopic pregnancy, the number of following deliveries was lower by almost half (45%), compared with women who had a miscarriage.

When the ectopic pregnancy group was compared to the women whose first pregnancy resulted in birth, there was no important difference discovered. The women who had the ectopic pregnancies had a 5% lower number of later pregnancies, which resulted in one child less during follow-up.

Dr Kårhus explained:

“It is not surprising that there was little difference between the women who had an ectopic pregnancy and women who delivered a baby from their first pregnancy. We think women with a first ectopic pregnancy have to try harder to achieve the number of deliveries they wish. However, their attempts are counterbalanced by the fact they are less fertile, and, therefore, ultimately they end up with one less birth.”

When the women whose first pregnancy was aborted were compared with those who were not pregnant at all in the matched years, the number of successful deliveries among the group with the ectopic pregnancies was respectively lowered by 11% and 31%.

Kårhus concluded: “”These results indicate that fertility is compromised in women whose first pregnancy is ectopic and even after 30 years they have significantly fewer children compared with other women. We had expected that, over time, women would compensate for their reduced fertility by making more attempts to become pregnant. However, our results demonstrate that these extra attempts at pregnancy do not result in the same number of babies for women whose first pregnancy was ectopic compared with other women.”

The trial also determined that women who had ectopic first pregnancies were not as likely to have a subsequent miscarriage or induced abortion, a 54% and 28% lower risk respectively, than the women whose first pregnancy resulted in miscarriage.

A study published in PLoS Medicine in June 2012, found that women whose first pregnancy was an ectopic one were less likely to conceive in future, had a greater risk of subsequent ectopic pregnancies, but were no more likely than first time mothers to suffer complications in an ongoing pregnancy.

Written by Christine Kearney