Most women have some nausea or vomiting, or “morning sickness”, during the first trimester of pregnancy.  Some women, however, have a more severe and persistent pattern of nausea and vomiting called hyperemesis gravidarum (HG).  A new study demonstrates that depression is more common in women suffering from HG and that it may persist into the postpartum period.

In this prospective case–control study, women from two London hospitals were assessed using validated questionnaires and psychological symptoms were compared between women with a diagnosis of HG (n=106) and a control group of pregnant women without significant nausea and vomiting of pregnancy (NVP, n=108). The Edinburgh Postnatal Depression Scale (EPDS) was used to measure depressive symptoms, with a cut-off of >

13 signifying probable depression.  The Maternal-to-Infant Bonding Scale was used during the postpartum period to assess the quality of bonding.

Compared to the controls without significant NVP, women with HG were younger (p=<0.001), more likely to be of Black/Afro-Caribbean ethnicity (p=0.010), single (p=0.016), were more likely to live with relatives (p=0.003) or in social housing (p=0.017) and were of lower educational status (p=0.006). 

At entry into the study, the mean EPDS score in the HG group was 12.3 (SD 6.1) compared to a mean of 4.8 (SD 3.2) in the control group (p=<0.001).  During pregnancy, 49% of the women with HG had probable depression compared to 6% of the controls (OR 14.4, 95% CI 5.29 to 39.44).  Of note, there was no significant difference between cases and controls in terms of previous history of mental health conditions at the time of recruitment (15% in cases and 19% in controls).

At 6 weeks postpartum, 29% of women in the HG group had probable depression versus 7% of the controls (OR 5.2, CI 1.65 to 17.21). The researchers did not observe a direct association between HG and infant bonding.  However, women with probable depression during pregnancy identified more problems with bonding on the Maternal-to-Infant Bonding Scale at 6 weeks postpartum, indicating a negative impact of depression (which was more common in women with HG) on infant bonding.

This study is consistent with previous studies demonstrating high rates of depression and anxiety among women suffering from HG.  On the one hand, the results are not too surprising.  HG is a severe and disabling illness which may complicate an otherwise healthy pregnancy.  It is noteworthy that while 33% of the women with HG reported that their symptoms resolved before 20 weeks gestation, 36% of the women reported significant symptoms throughout the pregnancy.  

This study demonstrates that women with HG are also at higher risk for postpartum depression.  While HG itself did not impact infant bonding, postpartum depression, which was more common in women with HG, did.  Other studies have demonstrated that HG is frequently associated with PTSD symptoms which may also impact functioning.  

This report raises other questions.  What is the best way to manage the depressive symptoms that emerge in this setting?  Does treatment of the physical symptoms resolve the psychological symptoms?  Or does HG result in a more prolonged form of depression which persists beyond the physical resolution of the symptoms. Further study is required: however, this and other studies clearly identify women with HG as being vulnerable to depression both during and after pregnancy.

Ruta Nonacs, MD PhD

Mitchell-Jones N, Lawson K, Bobdiwala S, Farren JA, Tobias A, Bourne T, Bottomley C  Association between hyperemesis gravidarum and psychological symptoms, psychosocial outcomes and infant bonding: a two-point prospective case-control multicentre survey study in an inner city setting.  BMJ Open. 2020 Oct 13;10(10):e039715. Free Article.