Pregnancy risks higher for women who were preemies

Women who were born prematurely may face a higher risk of complications in pregnancy, a new Quebec study suggests.

"Our population-based study showed an increased risk of hypertensive and diabetic complications of pregnancy associated with preterm birth, especially among women born before 32 weeks' gestation," Dr. Anne Monique Nuyt, a neonatologist and researcher at Montreal's Sainte-Justine University Hospital, and her co-authors conclude in the study in this week's Canadian Medical Association Journal.

The study comes as researchers are trying to understand why almosteight per cent of babies areborn pretermin Canada, and the rate has been increasing for 30 years.

They know that a woman whose weight was low at birth has a higher risk of issues like gestational diabetes during pregnancy. But it's unclear whether being born preterm at less than 32 weeks also carries such risks.

The CMAJ study suggests the answer could be yes.

The researchers said being too small for gestational age in terms of birth weight did not account for their findings. In the paper, they note that pregnancy can be considered a "stress test" for future cardiovascular and metabolic health, such as developing high blood pressure and Type 2 diabetes.

The researchers analyzed data on 7,405 women born preterm and 16,714 women born at term between 1976 and 1995 using records from the province's universal databases.

Of the preterm women, 554 were less than 32 weeks at birth, and 6,851 were at 32 to 36 weeks' gestation.

Overall, nearly 20 per cent of women born at less than 32 weeks had at least one pregnancy complication, compared with 13 per cent among those born at 32 to 36 weeks and almost 12 per cent for those born at term.

Stay informed, women advised

Nuyt wanted health-care providers to consider the impact of patients' preterm birth when offering obstetric care, but said there's no reason for women to be alarmed.

"Certainly people should not be afraid of starting their family and of being pregnant. I think like anything else, being informed and therefore in turn making sure the health professional that's taking care of you is also informed is simply the key.

"And probably this might guide some tighter followup of making sure, for example, if there is a gestational diabetes, it is well-controlled."

The study was unable to show acause and effect, namely if being born prematurely leads to pregnancy complications.

"We must keep in mind that being born preterm is a predispositionof sorts but is not the only contributor and thus other factors can be addressed and targeted to help reduce pregnancy-related complications,"Kristi Adamo, a research scientist at the Children's Hospital of Eastern Ontario Research Institute in Ottawa, said in an email.

The researchers also lacked information other factors that could be playing a role, such as socioeconomic status, ethnicity, lifestyle factors, family history and obesity that can also affect the risk of pregnancy complications.

A previous review suggested thatoverweight woman have double the odds of developing gestational diabetes, noted Adamo, who investigates predictors of child birth weight.

In February, doctors in Toronto reported that some babies born to parents who immigrated from South Asia areincorrectly classifiedas underweight.

The Quebec study was funded by the Canadian Institutes of Health Research.