(RxWiki News) Any time you visit a new doctor's office, you are generally asked to fill out your medical history. This information can be particularly important for OB/GYNs when you are pregnant.
Chlamydia and gonorrhea are two very common sexually transmitted infections (STIs).
The risks for women with a previous chlamydia infection were significantly lower than for those with a previous gonorrhea infection .
No increased risks for having an underweight baby existed for women who had previously had either STI.
"Tell your OB/GYN about your medical history."
The study, led by Bette Liu, of the University of New South Wales in Sydney, Australia, looked at how pregnant women fared if they had previously had chlamydia or gonorrhea.
The researchers included in their study 354,217 women who had given birth to a single child in New South Wales between 1999 and 2008.
Among these women, 1 percent (3,658 women) had previously had chlamydia, and 0.06 percent (196 women) had previously had gonorrhea.
More than 80 percent of the women had been diagnosed with a sexually transmitted infection before becoming pregnant.
The researchers looked at whether giving birth early (having a preemie), having an underweight baby or having a stillbirth was any more common among women who had previously had one of these STIs.
Among all the women studied, 4.1 percent gave birth preterm (had a preemie), 12.1 percent had an underweight baby (small for the pregnancy week born) and 0.6 percent had a stillbirth.
The odds that a woman would have a preterm birth were about 17 percent greater (1.17 times) for women who had previously had chlamydia compared to women with no history of chlamydia or gonorrhea.
This risk of delivering early did not vary based on whether a woman had chlamydia more than a year before becoming pregnant, within the year before becoming pregnant or during pregnancy.
The odds that women with a prior chlamydia diagnosis had a stillbirth were about 1.4 times greater (40 percent greater) than the odds for women without either STI.
Those with a history of gonorrhea were about 2.5 times more likely to have a preterm birth and 2.4 times more likely to have a stillbirth, compared to women without either STI.
Women with a history of chlamydia or gonorrhea were no more likely than other women to have had an underweight baby.
The researchers therefore concluded that a history of sexually transmitted infections may be relevant for care providers in determining possible risks to expect during delivery for pregnant women.
Jennifer Mushtaler, MD, an obstetrician in Austin, Texas, said that OB/GYNs already recommend and screen for active infections of sexually transmitted infections during pregnancy.
"However, a history of prior infection should not be cause for worry," Dr. Mushtaler said. "In practice, I have not observed the risks the authors suggest from their study."
The study was published September 4 in the journal Sexually Transmitted Infections.
The research was funded by the New South Wales Centre for Health Record Linkage, the New South Wales Ministry of Health and the National Health and Medical Research Council. No conflicts of interest were reported.