Moms with bipolar disorder have an increased risk of giving birth prematurely (before 37 weeks), according to researchers from Uppsala University and the Karolinska Institutet.
Babies born to mothers with bipolar disorder also appear to be at higher risk for problems associated with fetal growth restriction, according to the new study.
Treatment for bipolar disorder typically includes taking mood stabilizing drugs like lithium, anticonvulsants or antipsychotics. Earlier studies have suggested that these drugs may be linked to pregnancy and birth complications. However, little was known of the effects on pregnancy and infants in women with untreated bipolar disorder.
So researchers set out to investigate the risks of pregnancy and birth complications in women with both treated and untreated bipolar disorder.
Researchers looked through data from three national health registers and found 320 mothers with treated bipolar disorder and 554 untreated mothers. Treated and untreated women were compared with all other women giving birth (331,263) between July 1, 2005 and December 31, 2009. Results were adjusted for several factors such as maternal age, weight, smoking status, cohabitation and a diagnosis of alcohol or substance use disorder.
Mothers with bipolar disorder were more likely to smoke, be overweight and have alcohol or substance abuse problems than unaffected mothers.
Mothers with bipolar disorder (both treated and untreated) had increased risks of caesarean delivery, instrumental delivery (use of a vacuum or forceps), and a non-spontaneous start to delivery (37 percent of treated women, 31 percent of untreated women, 21 percent of other women).
Bipolar mothers also had 50 percent increased risks of preterm birth compared with unaffected mothers (8 percent of treated and untreated women, 4 percent of other women).
Untreated mothers were more likely to give birth to a baby with a small head (microcephaly) and with episodes of low blood sugar levels (neonatal hypoglycaemia) compared to unaffected mothers.
The authors say that “mood-stabilizing treatment is probably not the sole reason for the increased risk of adverse pregnancy and birth outcomes previously observed in mothers with bipolar disorder.”
They also suggest that the role of treatment is still unclear as the overall outcomes “generally did not support a significant difference between untreated and treated” mothers.
The study is published in the British Medical Journal.