Early pregnancy problems warning
Complications are common in the first months of pregnancy
Expectant mothers who have complications early on should be supervised more closely in current and future pregnancies, a study suggests.
Problems in the first three months increase the risk of premature birth and other difficulties - in that pregnancy and subsequent ones.
The data from 75 studies also showed a history of miscarriages was linked to future premature births.
Experts said the research would help identify those at high risk.
The analysis presented at the European Society of Human Reproduction and Embryology (ESHRE) annual meeting looked at several common complications of the first three months of pregnancy.
It notches up our level of awareness that if someone has problems in early pregnancy, especially repeated problems, maybe we should be watching these women a bit more closely
Patrick O'Brien, obstetrician
Vaginal bleeding in the early weeks was associated with an increased risk of pre-eclampsia, premature delivery and more than double the risk of having a low birth weight or very low birth weight baby.
An accumulation of blood in the womb - intrauterine haematoma - increased these risks further.
Extreme early morning sickness was associated with a three times higher risk of premature delivery and a nearly three-fold risk of low birth weight.
Women who had been pregnant with twins but miscarried one baby very early in pregnancy also had increased risks of later problems.
A history of one or more miscarriages nearly doubled the risk in an ongoing pregnancy of preterm premature rupture of the membrane that surrounds the baby in the womb, and increased the risk of a premature birth.
If a previous pregnancy had to be terminated for any reason, premature birth was a risk in subsequent pregnancies.
Although the study did not address causes of risks in future pregnancies it could be related to underlying health problems or lifestyle factors, experts said.
Study leader Dr Robbert van Oppenraaij, from Erasmus MC University Medical Centre, in the Netherlands, said the extent of future complications was related to the severity or recurrence of the early problems.
"Events and complications in early pregnancy are amongst the most common complications in women during their pregnancy and can be extremely distressing for them.
"For the clinician it is important to interpret the symptoms and to understand not only the short-term consequences, but also the long-term consequences of these early pregnancy complications."
Tony Rutherford, chair of the British Fertility Society, said the results suggested that some patients would benefit from closer monitoring.
"It is a message that these patients need to have supervision.
"The main concern is with early birth and if we can try and identify these patients we can improve the outcome."
Patrick O'Brien, spokesman for the Royal College of Obstetricians and Gynaecologists, said the underlying reasons for some of the associations would include lifestyle factors such as smoking, nutrition and also conditions such as hypertension and diabetes.
"It notches up our level of awareness that if someone has problems in early pregnancy, especially repeated problems, maybe we should be watching these women a bit more closely."