Bleeding with your first baby could up pregnancy risks later on.
Women who bleed early in pregnancy but don't miscarry are at increased risk of pregnancy complications, and this risk carries over to their next pregnancy, according to a large new study from Denmark.
The findings suggest that doctors should keep a closer eye on pregnant women who have experienced first-trimester vaginal bleeding.
It's been shown that about half of women who have first-trimester bleeding will miscarry by 20 weeks of pregnancy, while women who bleed but don't miscarry are known to be more likely to have pregnancy complications. In the current study, the researchers investigated whether this risk might persist into a woman's next pregnancy.
They looked at records for nearly 800,000 Danish women who delivered a first baby between 1978 and 2007, and a subset of nearly 540,000 of these women who also had a second child during that time period.
Around 2% of women in both groups had first-trimester bleeding during their pregnancies. Among women who had bleeding in their first pregnancies, 6% delivered their babies early between 32 and 36 weeks' gestation, compared to about 4% of the women who had no bleeding.
Earlier pre-term delivery, at 28 to 31 weeks, was also more common in women with bleeding, as was a pregnancy complication called placental abruption, in which the placenta separates from the uterus before delivery.
According to the researchers, women who bled early in their first pregnancy but not in their second pregnancy were still at increased risk in their subsequent pregnancy for pre-term delivery and premature membrane rupture; 8.2% of these women delivered their babies at 32 to 36 weeks of pregnancy, compared to 2.2% of women with no bleeding; risks for earlier pre-term delivery were 4.8% and 2.7%, respectively.
4% of women who had experienced first-trimester bleeding in their first pregnancy had premature rupture of membranes in their second pregnancy, compared to 3% of women who did not have bleeding.
The researchers conclude, based on their observations, that early pregnancy bleeding, pre-term delivery, placental abruption and premature rupture of membranes may be related to one another, and could provide clues to the underlying causes of these complications.