Women who miscarry can go on to have successful pregnancies
Women who have had just one miscarriage are more likely to suffer complications in future pregnancies, research shows.
The University of Aberdeen study is the first of its kind to assess the impact of an initial miscarriage on the next ongoing pregnancy.
The women were 3.3 times more likely to have pre-eclampsia and 1.5 times more likely to have a premature baby.
The authors said these women should be monitored as well as those who have recurrent miscarriages.
Previous work has focussed on the consequences of three or more miscarriages (recurrent miscarriage), although for most women, a single miscarriage is far more likely.
Compared with women who enjoyed a successful first pregnancy, women with a history of one miscarriage were 1.7 times more likely to have a threatened miscarriage, where they have symptoms of a miscarriage but do not actually miscarry.
They were also 1.3 times more likely to have bleeding after 24 weeks in their subsequent pregnancy.
The study of more than 33,000 women, published in the British Journal of Obstetrics and Gynaecology, also found that women who suffered one miscarriage were more than twice as likely to have labour induced and almost six times as likely to an "instrumental" vaginal delivery, such as the use of forceps.
Preterm birth after 34 weeks gestation was 1.6 times more common, and low birthweight (less than 2,500g) was 1.6 times more common.
No cause for alarm
Lead researcher Dr Sohinee Bhattacharya said: "A single initial miscarriage increased the risks of pregnancy complications in the next continuing pregnancy compared to women who had a successful first pregnancy.
"While for most women these risks are small, increased obstetric surveillance should not be restricted only to women with multiple miscarriages."
Gail Johnson of the Royal College of Midwives said it was important for women to be aware of the risks, but said they should not be alarmed by the findings.
"Women who have had a miscarriage are able to have a successful pregnancy. If that pregnancy is complicated we can offer monitoring and treatment to improve the outcomes," she said.
Professor Philip Steer, BJOG editor-in-chief said, "The findings from this research are helpful to healthcare professionals caring for pregnant women.
"They provide us with an idea of the complications that may arise as a result of a previous miscarriage. This will help doctors in the management of the subsequent pregnancy."
He said one factor not assessed in the study was the interval between the miscarriage and the next pregnancy.
This is important because many previous studies have shown that an interval of less than six months between the miscarriage and the next pregnancy substantially increases the risk of pregnancy complications, and the risk does not reach a minimum until 18 months to two years, he said.
Research has shown that one in five pregnancies end in miscarriage in the first three months and one in 100 women have recurrent miscarriages.