Is pregnancy a teachable moment for diet and physical activity behaviour change? An interpretative phenomenological analysis of the experiences of women during their first pregnancy

OBJECTIVES: Pregnancy may provide a 'teachable moment' for positive health behaviour change, as a time when women are both motivated towards health and in regular contact with health care professionals. This study aimed to investigate whether women's experiences of pregnancy indicate that they would be receptive to behaviour change during this period. DESIGN: Qualitative interview study. METHODS: Using interpretative phenomenological analysis, this study details how seven women made decisions about their physical activity and dietary behaviour during their first pregnancy. RESULTS: Two women had required fertility treatment to conceive. Their behaviour was driven by anxiety and a drive to minimize potential risks to the pregnancy. This included detailed information seeking and strict adherence to diet and physical activity recommendations. However, the majority of women described behaviour change as 'automatic', adopting a new lifestyle immediately upon discovering their pregnancy. Diet and physical activity were influenced by what these women perceived to be normal or acceptable during pregnancy (largely based on observations of others) and internal drivers, including bodily signals and a desire to retain some of their pre-pregnancy self-identity. More reasoned assessments regarding benefits for them and their baby were less prevalent and influential. CONCLUSIONS: Findings suggest that for women who conceived relatively easily, diet and physical activity behaviour during pregnancy is primarily based upon a combination of automatic judgements, physical sensations, and perceptions of what pregnant women are supposed to do. Health professionals and other credible sources appear to exert less influence. As such, pregnancy alone may not create a 'teachable moment'. Statement of contribution What is already known on this subject? Significant life events can be cues to action with relation to health behaviour change. However, much of the empirical research in this area has focused on negative health experiences such as receiving a false-positive screening result and hospitalization, and in relation to unequivocally negative behaviours such as smoking. It is often suggested that pregnancy, as a major life event, is a 'teachable moment' (TM) for lifestyle behaviour change due to an increase in motivation towards health and regular contact with health professionals. However, there is limited evidence for the utility of the TM model in predicting or promoting behaviour change. What does this study add? Two groups of women emerged from our study: the women who had experienced difficulties in conceiving and had received fertility treatment, and those who had conceived without intervention. The former group's experience of pregnancy was characterized by a sense of vulnerability and anxiety over sustaining the pregnancy which influenced every choice they made about their diet and physical activity. For the latter group, decisions about diet and physical activity were made immediately upon discovering their pregnancy, based upon a combination of automatic judgements, physical sensations, and perceptions of what is normal or 'good' for pregnancy. Among women with relatively trouble-free conception and pregnancy experiences, the necessary conditions may not be present to create a 'teachable moment'. This is due to a combination of a reliance on non-reflective decision-making, perception of low risk, and little change in affective response or self-concept.

Deficiency in catechol-O-methyltransferase and 2-methoxyoestradiol is associated with pre-eclampsia

Despite intense investigation, mechanisms that facilitate the emergence of the pre-eclampsia phenotype in women are still unknown. Placental hypoxia, hypertension, proteinuria and oedema are the principal clinical features of this disease. It is speculated that hypoxia-driven disruption of the angiogenic balance involving vascular endothelial growth factor (VEGF)/placenta-derived growth factor (PLGF) and soluble Fms-like tyrosine kinase-1 (sFLT-1, the soluble form of VEGF receptor 1) might contribute to some of the maternal symptoms of pre-eclampsia. However, pre-eclampsia does not develop in all women with high sFLT-1 or low PLGF levels, and it also occurs in some women with low sFLT-1 and high PLGF levels. Moreover, recent experiments strongly suggest that several soluble factors affecting the vasculature are probably elevated because of placental hypoxia in the pre-eclamptic women, indicating that upstream molecular defect(s) may contribute to pre-eclampsia. Here we show that pregnant mice deficient in catechol-O-methyltransferase (COMT) show a pre-eclampsia-like phenotype resulting from an absence of 2-methoxyoestradiol (2-ME), a natural metabolite of oestradiol that is elevated during the third trimester of normal human pregnancy. 2-ME ameliorates all pre-eclampsia-like features without toxicity in the Comt(-/-) pregnant mice and suppresses placental hypoxia, hypoxia-inducible factor-1alpha expression and sFLT-1 elevation. The levels of COMT and 2-ME are significantly lower in women with severe pre-eclampsia. Our studies identify a genetic mouse model for pre-eclampsia and suggest that 2-ME may have utility as a plasma and urine diagnostic marker for this disease, and may also serve as a therapeutic supplement to prevent or treat this disorder.

Can the biology of VEGF and haem oxygenases help solve pre-eclampsia?

Pre-eclampsia, a pregnancy-specific multi-organ syndrome characterized by widespread endothelial damage, is a new risk factor for cardiovascular disease. No therapies exist to prevent or treat this condition, even to achieve a modest improvement in pregnancy length or birth weight. Co-administration of soluble VEGFR-1 [VEGF (vascular endothelial growth factor) receptor-1; more commonly known as sFlt-1 (soluble Fms-like tyrosine kinase-1)] and sEng (soluble endoglin) to pregnant rats elicits severe pre-eclampsia-like symptoms. These two anti-angiogenic factors are increased dramatically prior to the clinical onset of pre-eclampsia and are quite possibly the 'final common pathway' responsible for the accompanying signs of hypertension and proteinuria as they can be reversed by VEGF administration in animal models. HO-1 (haem oxygenase-1), an anti-inflammatory enzyme, and its metabolite, CO (carbon monoxide), exert protective effects in several organs against oxidative stimuli. In a landmark publication, we showed that the HO-1 pathway inhibits sFlt-1 and sEng in cultured cells and human placental tissue explants. Both CO and NO (nitric oxide) promote vascular homoeostasis and vasodilatation, and activation of VEGFR-1 or VEGFR-2 induced eNOS (endothelial nitric oxide synthase) phosphorylation, NO release and HO-1 expression. Our studies established the HO-1/CO pathway as a negative regulator of cytokine-induced sFlt-1 and sEng release and eNOS as a positive regulator of VEGF-mediated vascular morphogenesis. These findings provide compelling evidence for a protective role of HO-1 in pregnancy and identify it as a target for the treatment of pre-eclampsia. Any agent that is known to up-regulate HO-1, such as statins, may have potential as a therapy. Any intervention achieving even a modest prolongation of pregnancy or amelioration of the condition could have a significant beneficial health impact worldwide.

Unravelling the theories of pre-eclampsia:Are the protective pathways the new paradigm?

Pre-eclampsia is a vascular disorder of pregnancy where anti-angiogenic factors, systemic inflammation and oxidative stress predominate, but none can claim to cause pre-eclampsia. This review provides an alternative to the 'two-stage model' of pre-eclampsia in which abnormal spiral arteries modification leads to placental hypoxia, oxidative stress and aberrant maternal systemic inflammation. Very high maternal soluble fms-like tyrosine kinase-1 (sFlt-1 also known as sVEGFR) and very low placenta growth factor (PlGF) are unique to pre-eclampsia; however, abnormal spiral arteries and excessive inflammation are also prevalent in other placental disorders. Metaphorically speaking, pregnancy can be viewed as a car with an accelerator and brakes, where inflammation, oxidative stress and an imbalance in the angiogenic milieu act as the 'accelerator'. The 'braking system' includes the protective pathways of haem oxygenase 1 (also referred as Hmox1 or HO-1) and cystathionine-γ-lyase (also known as CSE or Cth), which generate carbon monoxide (CO) and hydrogen sulphide (H2S) respectively. The failure in these pathways (brakes) results in the pregnancy going out of control and the system crashing. Put simply, pre-eclampsia is an accelerator-brake defect disorder. CO and H2S hold great promise because of their unique ability to suppress the anti-angiogenic factors sFlt-1 and soluble endoglin as well as to promote PlGF and endothelial NOS activity. The key to finding a cure lies in the identification of cheap, safe and effective drugs that induce the braking system to keep the pregnancy vehicle on track past the finishing line.

Pregnancy complications in hyperemesis-affected pregnancy:a large hospital database study

Objective: Vomiting in pregnancy is a common condition affecting 80% of pregnant women. Hyperemesis is at one end of the spectrum, seen in 0.5–2% of the pregnant population. Known factors such as nulliparity, younger age and high body mass indexare associated with an increased risk of this condition in the first trimester. Late pregnancy complications attributable to hyperemesis, the pathogenesis of which is poorly understood, have not been studied in large population-based studies in the United Kingdom. The objective of this study was to determine a plausible association between hyperemesis and pregnancy complications,such as pregnancy-related hypertension, gestational diabetes and liver problems in pregnancy, and the rates of elective (ElCS) and emergency caesarean section (EmCS). Methods: Using a database based on ICD-10 classification, anonymised data of admissions to a large multi-ethnic hospital in Manchester, UK between 2000 and 2012 were examined.Notwithstanding the obvious limitations with hospital database-based research, this large volume of datasets allows powerful studies of disease trends and complications.Results Between 2000 and 2012, 156 507 women aged 45 or under were admitted to hospital. Of these, 1111 women were coded for hyperemesis (0.4%). A greater proportion of women with hyperemesis than without hyperemesis were coded forhypertensive disorders in pregnancy such as pregnancy-induced hypertension, pre-eclampsia and eclampsia (2.7% vs 1.5%;P=0.001). The proportion of gestational diabetes and liver disorders in pregnancy was similar for both groups (diabetes:0.5% vs. 0.4%; P=0.945, liver disorders: 0.2% vs. 0.1%;P=0.662). Hyperemesis patients had a higher proportion of elective and emergency caesarean sections compared with the non-hyperemesis group (ElCS: 3.3% vs. 2%; P=0.002, EmCS: 5% vs.3%; P=0.00). Conclusions: There was a higher rate of emergency and elective caesarean section in women with hyperemesis, which could reflect the higher prevalence of pregnancy-related hypertensive disorders(but not diabetes or liver disorders) in this group. The factors contributing to the higher prevalence of hypertensive disorders arenot known, but these findings lead us to question whether there is a similar pathogenesis in the development of both the conditions and hence whether further study in this area is warranted.