Overuse of mobile phones and HIV medicines is bad for pregnant mothers, researchers have warned.
A follow-up of 322 Kenyan mothers who conceived while on antiretroviral (ARV) drugs showed high rates of premature deliveries, miscarriages and stillbirths.
Experts told an HIV conference in Paris, France, that urgent investigation was needed to determine the effects of ARVs on unborn children.
In her presentation, Susan Cu-Uvin of Brown University in the US said a joint study with the Kenya Medical Research Institute (Kemri) showed cause for worry for HIV-positive women who planned to conceive.
Of the 322 women in the study and who had conceived while on ARVs, there were 164 live births, out of which more than half (53 per cent) were premature. The study recorded 11 stillbirths, 51 miscarriages and 28 abortions.
"Women who conceived while on Antiretroviral Treatment (ART) in these trials had high numbers of preterm births and other adverse pregnancy outcomes," Dr Cu-Uvin explained.
But ARVs are not the only threats to the unborn child. New evidence from Japan shows that pregnant women who overuse mobile phones are likely to deliver underweight babies.
The study by the Kumamoto University of Japan says excessive mobile phone use during pregnancy may be a risk factor for lower birth weight babies.
Low birth weight has been linked to stunted growth, low immunity and chronic diseases in later life.
In the Japanese study appearing in the journal of Environmental Health and Preventive Medicine, the researchers had followed 521 pregnant women and their use of mobile phones.
The investigators collected data on their phone usage, use times, location of the phone during the day and at night, and whether their phones were either on or off when they went to bed.
The team reported that single mothers used mobile phones more than married ones. They linked this to loneliness and depression.
"We also found that the excessive use group preferred to place the mobile phone in the trouser or shirt pocket," says the study.
This they interpreted to mean that the excessive use group preferred to have the mobile phone in an easily accessible location.
The study suggests that excessive mobile phone use during pregnancy may cause mental problems such as anxiety and depression, and other health problems such as sleep deprivation, which eventually affect unborn babies.
"Sleep time was later in the excessive use group than in the ordinary use group, and therefore, excessive users may have poor sleep quality; the maternal health and mental problems may lead to a low birth weight and neonatal health which may eventually necessitate infant emergency transport," they said.