There are many factors that can lead to a birth occurring before the pregnancy has reached term at 37 weeks. Common causes are dehydration or smoking by the mother. Complications associated with pre-term labor can be low birth weight and problems with the baby’s organs, which may not be completely formed before 37 weeks.
Studies have identified the use of medications used to treat bipolar disorder as a factor involved in pre-term deliveries. Medications for treating bipolar disorder include antipsychotics, anticonvulsants or lithium-based drugs. However, while treatments for the disorder have been linked to early deliveries, there has been no ability to distinguish what role medications play versus the disorder itself.
Now a study from researchers at Uppsala University and the Karolinska Institutet seeks to close the gap in the understanding of the role of bipolar disorder in pre-term deliveries. The findings released by the researchers have found that bipolar disorder is associated with an increased likelihood of delivering a baby early.
In addition, report the researchers, babies born to mothers with bipolar disorder may have an increased risk for other complications, including fetal growth restriction.
The researchers investigated deliveries among mothers with bipolar disorder, comparing the instances of both treated and untreated bipolar disorder.
The researchers accessed information from three separate national health registers and identified 320 mothers with bipolar disorder who had been treated with medication, as well as 554 with bipolar disorder who had not been treated.
The researchers also compared the results of delivery among both treated and untreated bipolar disorder patients and compared them with the results of 331,263 women who did not have a diagnosis of bipolar disorder. All of the deliveries took place between July of 2005 and December of 2009.
The researchers also examined the deliveries in light of factors such as weight, maternal age, smoking, cohabitation and substance use disorders. The results revealed that mothers with a bipolar disorder diagnosis were more likely to be overweight, smokers and have a substance use disorder when compared with mothers who did not have bipolar disorder.
Mothers diagnosed with bipolar disorder who were treated and untreated were at an increased risk for instrumental delivery involving a forceps or vacuum procedure, caesarean delivery or a non-spontaneous initiation of delivery.
The researchers found that among those with bipolar disorder, there was a 50 percent increased chance of pre-term birth when examined alongside mothers who did not have a diagnosis for bipolar disorder.
Women who were untreated were at an increased risk for delivering a baby with a small head (microephaly) and with low blood sugar when compared with the general population of mothers.
The researchers note that the treatments used to stabilize mood in bipolar disorder patients is likely not the sole cause of pre-term labor among mothers diagnosed with the disorder.
The results are published in the British Medical Journal.