In a recent study by Gerardin and colleagues, the authors note that more research has been done to demonstrate the consequences of postpartum depression than depression during pregnancy (also called antenatal or prenatal depression).  Infants born to mothers with depression during pregnancy have been demonstrated to have lower scores on motor behavior and more crying and irritability.  Few studies, however, have assessed the longer-term effects of antenatal depression.

In studies of postpartum depression, it has been observed that male infants may be more vulnerable to the effects of maternal depression than female infants. Gerardin and colleagues conducted a prospective study to ascertain whether the gender of the baby influenced the effects of prenatal depression upon infant development at one year of age.  In this 20-month case control study, mothers were recruited from a prenatal care ward at a hospital in Paris.  Women were eligible to participate if they were pregnant, between 20-38 years of age, were fluent in French, and were having their first baby.   Women were excluded if they had acute or chronic medical conditions, were carrying multiples, had an observed fetal malformation, or were using drugs, alcohol, or cigarettes (over 15 cigarettes per day).  A total of 164 women were included who were eligible for the study.

Mothers were interviewed during the third trimester at the beginning of the eighth month of pregnancy, and again three days after delivery.   The interviews included gathering of sociodemographic information, the Edinburgh Postnatal Depression Scale (EPDS), Center for Epidemiologic Studies Depression Scale (CES-D), and the Montgomery-Asberg Depression Rating Scale (MADRS).  The subjects were also assessed using the DSM-IV criteria for major depressive disorder, verified with the Mini-International Neuropsychiatric Interview (MINI).  They were categorized as depressed if they had a MADRS score > 15 and met DSM-IV criteria for major depressive disorder.

Newborns were assessed by psychologists blinded to the mothers’ condition (depressed or not depressed during pregnancy).   Newborns were assessed with the Neonatal Behavioral Assessment Scale (NBAS) within 3 days of delivery.    At one year, the mothers completed questionnaires regarding child development (Infant-Toddler Social and Emotional Assessment).  Mothers were assessed with depression rating scales at 2, 6 and 12 months after delivery.

Approximately 20% of the mothers were depressed during the assessment period, with 14% of the sample experiencing depression that began during pregnancy.  Those who experienced depression only during the postpartum period (but not during pregnancy) were excluded from the analyses.

The prenatal depression group included 34 mothers, and there were 79 in the non-depressed control group.  There were no sociodemographic differences between the two groups.  Maternal weight gain was similar between the groups.  There were no differences in gestational age at delivery, type of delivery, or Apgar scores.  Babies born to mothers with depression were slightly heavier and had larger head circumferences, but these were within normal range.  Similar percentiles selected to breastfeed from both groups (72-75%).  Mothers in the depressed group were more likely to combine breastfeeding with bottle feeding.

Infant outcomes

Neonatal Assessment (within 3 days of delivery):  Within the depressed group, there were no differences on the NBAS scores between male and female infants at the neonatal assessment.  In the control group, female babies performed better on the habituation subscale than males.  Between group comparisons revealed that male newborns of mothers in the control group had higher NBAS scores than males in the depressed group on motor skills and regulation of states.  Control newborns overall had better scores on regulation of states than babies of mothers with depression.  Females overall scored better than males across the NBAS.

For the Neonatal Behavioral Assessment Scale (NBAS) Scores, there were 16 males and 11 females whose mothers had antenatal depression, and 38 males and 26 females whose mothers were controls.  The findings of statistical significance were as follows:

1) On the dimension of habituation (“ability to respond and inhibit discrete stimuli while asleep”), among the control group only, girls scored better than boys,

2) On the dimension of motor skills (“motor performance and quality of movement and tone”), control boys performed better than boys of mothers with antenatal depression,

3) On the dimension of regulation of states (“infant’s ability to regulate his or her states when facing increasing levels of stimulation”), control boys performed better than boys of mothers with antenatal depression, and overall control babies (boys and girls )performed better than babies of mothers with antenatal depression.

Infant development at 1 year: There were no significant differences between males and females among babies whose mothers experienced depression during pregnancy.  Among controls, females scored better than males on some items (compliance, prosocial peer relations).  Males of mothers who had depression during pregnancy had higher anxiety scores at one year of age than males in the control group.   Girls of mothers who had depression during pregnancy had higher oppositional/defiant scores at one year of age than girls in the control group.   Scores for generalized anxiety were higher overall for babies of mothers who were depressed during pregnancy than among controls, which was also significant for boys compared between groups but not for girls.

Limitations:  The investigators stated that they assumed that women were not on psychotropic medication, and no listing of medications taken during pregnancy reported.   It is difficult to ascertain the clinical significance of the findings.  There were multiple comparisons made among the babies of mothers with prenatal depression and controls; the small number of infants in certain groups may have limited the statistical significance of certain analyses.

Summary: The authors noted some differences between babies of mothers who suffered from antenatal depression, after carefully excluding those who had postpartum depression.  There were sub-item differences between genders for controls and the babies of mothers with antenatal depression, although the clinical significance of these differences is unclear.  This was a carefully conducted study, and a large study of its kind, but among the various groups of children studied (depressed vs. control mothers, separated by gender), actual numbers were small.  This study demonstrated the feasibility to assess antenatal depression in mothers separately from postpartum depression, and to assess babies longitudinally.  More research is needed to determine the short- and long-term clinically significant effects of antenatal depression upon babies.  Gender may be a modulator of resilience or risk for developmental outcomes.

Marlene Freeman, MD

Gerardin P, Wendland J, Bodeau N, Galin A, Bialobos S, Tordjman S, Mazet P, Darbois Y, Nizard J, Dommergues M, Cohen D. Depression During Pregnancy: Is the Developmental Impact Earlier in Boys? A Prospective Case-Control Study. J Clin Psychiatry; 72(3): 378-387.