Hyperemesis gravidarum: pathogenesis and the use of antiemetic agents

The Role of hCG and Histamine in Emesis Gravidarum and Use of a Chewing Gum Containing Vitamin C as a Treatment Option: A Double-Blinded, Randomized, Controlled Trial

Background: Nausea and vomiting in pregnancy (NVP), or emesis gravidarum, is a frequent complication of early gestation with unclear causes, suspected to involve genetic, hormonal, and gastrointestinal factors. Our study investigated the association of human chorionic gonadotropin (hCG), histamine, diamine oxidase (DAO), thyroxine and pyridoxine and the severity of NVP symptoms and assessed the efficacy of a vitamin C-containing chewing gum as a potential NVP treatment. Methods: In this prospective, double-blinded, randomized, controlled trial, 111 participants were assigned to receive vitamin C-containing chewing gum, placebo gum, or no treatment at two follow-ups during early pregnancy. Maternal serum levels of hCG, histamine, DAO, thyroxine, and pyridoxine were measured and correlated with NVP severity using the Pregnancy-Unique Quantification of Emesis and Nausea (PUQE-24) score. Results: Elevated maternal hCG levels were significantly associated with an increased PUQE-24 score (p < 0.001), while histamine levels showed no significant correlation (p = 0.68). Maternal DAO levels negatively correlated with NVP symptoms (p < 0.001) and elevated thyroxine (p < 0.001) and pyridoxine levels (p < 0.001) were associated with increased PUQE-24 scores. The vitamin C-containing chewing gum did not demonstrate efficacy in alleviating NVP symptoms compared to placebo gum or no treatment during the first (p = 0.62) and second follow-up visits (p = 0.87). Conclusions: Our study underscores the complexity of factors contributing to NVP, highlighting the significant roles of hCG and DAO, while histamine levels appear unrelated. Maternal thyroxine and pyridoxine levels also significantly correlate with NVP symptoms. Vitamin C-containing chewing gum was not effective as a treatment for NVP. Further large-scale studies are needed to better understand these interactions and develop targeted treatments in the future.

Hyperemesis Gravidarum: Risk of Recurrence in Subsequent Pregnancies

This study aimed to examine whether the recurrence risk of hyperemesis gravidarum (HG) is modified by the timing of diagnosis, the severity of illness, and interpregnancy interval. The Kaiser Permanente Southern California 1998-2020 longitudinally linked medical records were used to examine the recurrence risk of HG in the first two (n = 93,444) and first three (n = 17,492) successive pregnancies. The timing of diagnosis- and the severity of illness-specific recurrence risks were examined by estimating the adjusted relative risks (aRR). The risks of HG in the second pregnancy among patients with and without previous HG were 23.8% and 3.4%, respectively (aRR: 8.20; 95% confidence interval [CI]: 7.52, 8.94). The recurrence risk persisted regardless of the trimester at diagnosis and the gestational age of delivery in the first pregnancy. The recurrence risk was greater for patients with metabolic disturbances requiring in-hospital treatment (30.0%) than those managed on an outpatient basis (18.6%) in the first pregnancy (aRR: 10.84 95% CI: 9.66, 12.16). Although Asian/Pacific Islander (RR = 12.9) and White (RR = 8.9) patients had higher HG recurrence risk regardless of the gestational age at delivery in the first pregnancy, all patients had significant recurrence risk only if their first pregnancy was delivered after 32 weeks of gestation. African American patients had the highest recurrence rate (34.4%). HG recurrence risk was unaffected by interpregnancy interval and correlated with the number of previous pregnancies complicated by HG. There is an increased recurrence risk of HG in subsequent pregnancies that is influenced by race/ethnicity and gestational age at delivery. The number of pregnancies complicated by HG synergistically adds to the recurrence risk.

Liver Disease During Pregnancy: A Challenging Clinical Issue

One of the least studied topics in the field of obstetrics is liver disease during pregnancy, which creates a challenge for both gynecologists and hepatologists. Approximately 3% of pregnant women are affected by some form of liver disease during pregnancy. Some of these conditions can be fatal for both the mother and child. In addition, 3 types of liver disease need to be differentiated during pregnancy. One type is liver disease directly related to pregnancy, which can occur at a specific time during pregnancy. Another type is liver disease not related to pregnancy, which can occur at any time, such as viral- or drug-induced hepatitis. Furthermore, pregnancy can occur in women with pre-existing liver disease. It is essential that the clinicians are familiar with this disorder so they can respond promptly and appropriately in all of these situations, especially when emergency delivery is needed and must not be postponed.

Cardiovascular risk profile at the age of 40-45 in women with previous hyperemesis gravidarum or hypertensive disorders in pregnancy: A population-based study

OBJECTIVE

To assess midlife cardiovascular risk profiles in women with a history of hyperemesis or hypertensive disorders in pregnancy compared to women with none of the studied pregnancy complications.

STUDY DESIGN

Population-based study. Cardiovascular risk factors at the age of 40-45 among women with previous singleton births only were studied through linkage of the Norwegian Birth Registry and a Norwegian screening program (the Age 40 Program).

MAIN OUTCOME MEASURES

Family history of coronary heart disease, body mass index, smoking, physical activity, systolic and diastolic blood pressure, heart rate, cholesterol, triglycerides, antihypertensive treatment and diabetes.

RESULTS

Among 178,231 women participating in the Age 40 Program with previous singleton births; 2140 (1.2%) had experienced hyperemesis and 13,348 (7.5%) hypertensive disorders in pregnancy. Women who had suffered from hyperemesis were less physically active. The differences in mean systolic blood pressure and body mass index were probably clinically irrelevant. In women with a history of hypertensive disorders in pregnancy, systolic and diastolic blood pressure and body mass index were higher, and they were more likely to report diabetes in midlife. Women who had suffered from hyperemesis or hypertensive disorders in pregnancy were less likely to be daily smokers.

CONCLUSION

Women with hypertensive disorders in pregnancy seemed to have an unfavorable cardiovascular risk profile in midlife compared to women with uncomplicated pregnancies. In contrast there was no consistent evidence of increased risk subsequent to hyperemesis gravidarum. The proportion of daily smokers was lower in women with either of the two pregnancy complications.

A meta-analysis of the association between Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum

BACKGROUND

Hyperemesis gravidarum remains a common, distressing, and significant yet poorly understood disorder during pregnancy. The association between maternal Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum has been increasingly recognized and investigated. This study thus aimed to provide an updated review and meta-analysis of the topic.

METHODS

Using the search terms (H. pyloriOR Helicobacter ORHelicobacter pyloriOR infection) AND (pregnancy OR emesis OR hyperemesis gravidarum OR nausea OR vomiting), a preliminary search on the PubMed, Ovid, Web of Science, Google Scholar, and WanFang database yielded 372 papers published in English between January 1st, 1960 and June 1st, 2017.

RESULTS

A total of 38 cross-sectional and case-control studies, with a total of 10 289 patients were eligible for review. Meta-analysis revealed a significant association between H. pylori infection and hyperemesis gravidarum during pregnancy, with a pooled odds ratio of 1.348 (95% CI: 1.156-1.539, P < .001). Subgroup analysis found that serologic and stool antigen tests were comparable methods of detecting H. pylori as they yielded similar odds ratios.

LIMITATIONS

Although the studies did not have high heterogeneity (I²  = 28%), publication bias was observed, and interstudy discrepancies in the diagnostic criteria adopted for hyperemesis gravidarum limit the reliability of findings. Also, 15 of the included studies were from the same country (Turkey), which could limit the generalizability of current findings. The prevalence of H. pylori infection varies throughout the world, and there may also be pathogenic differences as most strains of H. pylori in East Asia carry the cytotoxin-associated gene A gene.

CONCLUSION

H. pylori infection was associated with an increased likelihood of hyperemesis gravidarum during pregnancy. Given the high prevalence of H. pylori infections worldwide, detecting H. pylori infection and the eradication of maternal H. pylori infection could be part of maternal hyperemesis gravidarum management. Further confirmation with robust longitudinal studies and mechanistic investigations are needed.

Hyperemesis gravidarum and long-term mortality: a population-based cohort study

OBJECTIVE

To investigate whether exposure to hyperemesis gravidarum (HG) is associated with increased maternal long-term mortality.

DESIGN

Population-based cohort study.

SETTING

Medical Birth Registry of Norway (1967-2002) linked to the Cause of Death Registry.

POPULATION

Women in Norway with singleton births in the period 1967-2002, with and without HG. Women were followed until 2009 or death.

METHODS

Cox proportional hazard regression model was applied to estimate hazard ratios (HRs) with 95% confidence interval (CI).

MAIN OUTCOME MEASURES

The primary outcome was all-cause mortality during follow up. Secondary outcomes were cause-specific mortality (cardiovascular mortality, deaths due to cancer, external causes or mental and behavioural disorders).

RESULTS

Of 999 161 women with singleton births, 13 397 (1.3%) experienced HG. During a median follow up of 26 years (25 902 036 person-years), 43 470 women died (4.4%). Women exposed to HG had a lower risk of long-term all-cause mortality compared with women without HG (crude HR 0.82; 95% CI 0.75-0.90). When adjusting for confounders, this reduction was no longer significant (adjusted HR 0.92; 95% CI 0.84-1.01). Women exposed to HG had a similar risk of cardiovascular death as women not exposed (adjusted HR 1.04; 95% CI 0.83-1.29), but a lower long-term risk of death from cancer (adjusted HR 0.86; 95% CI 0.75-0.98).

CONCLUSION

In this large population-based cohort study, HG was not associated with an increased risk of long-term all-cause mortality. Women exposed to HG had no increase in mortality due to cardiovascular disease, but had a reduced risk of death from cancer.

TWEETABLE ABSTRACT

Population-based cohort study: Hyperemesis was not associated with an increased risk of long-term mortality.

Hyperemesis gravidarum is associated with increased maternal serum ischemia-modified albumin

AIM

Our objective was to measure the circulating levels of ischemia-modified albumin (IMA) among pregnant with hyperemesis gravidarum (HEG) and to compare their levels with age- and body mass index (BMI)-matched control pregnant women.

METHOD

The pregnant subjects were classified into the HEG group diagnosed with HEG (n=45) and age- and BMI-matched control group without a diagnosis of HEG (n=45) during their pregnancies. Serum IMA, hemoglobin, hematocrit, white blood cells, platelet, fasting blood glucose, creatinine, lipid profile, aspartate aminotransferase (AST) urea, alanine aminotransferase (ALT), sodium, potassium and thyroid-stimulating hormone (TSH) levels of the groups were measured.

RESULT

Serum hemoglobin, hematocrit, white blood cells, platelet, fasting blood glucose, creatinine, lipid profile, AST, urea, ALT, sodium, potassium and TSH levels of the groups were statistically similar. Serum IMA values were significantly higher in subjects with HEG compared to the subjects without HEG.

CONCLUSIONS

We found that HEG was related to increased maternal serum IMA levels. HEG might be due to an ischemic intrauterine environment leading to elevated serum IMA concentrations.

Nausea and vomiting of pregnancy - What's new?

Nausea and vomiting of pregnancy (NVP) is one of the most common disorders of pregnancy. The symptoms occur predominantly during the first trimester, although in a subgroup of patients they can continue throughout the entire pregnancy and can affect the woman's quality of life. A small percentage of women develop a severe form of NVP called hyperemesis gravidarum (HG) that if left untreated may lead to significant maternal morbidity and adverse birth outcomes. Overall, the morbidity in pregnant women with NVP is significant, although it tends to be underestimated. The pathogenesis of NVP remains unclear, but there is consensus that the disorder is multifactorial and that various genetic, endocrine and infectious factors may be involved. The treatment of NVP can be challenging as the optimal targets for therapy are not known. Currently, the therapy used depends on the severity of the disorder and it is focused on improving the symptoms while minimizing risks to mother and fetus. Therapies range from dietary changes, pharmacologic treatment or hospitalization with intravenous fluid replacement and nutrition therapy. The aims of this review are 1) to provide an overview of NVP, 2) to present possible links between the most important factors associated with the pathogenesis of NVP and 3) to discuss the effectiveness and safety of the pharmacologic and non-pharmacologic options available to treat this disorder.

AISF position paper on liver disease and pregnancy

The relationship between liver disease and pregnancy is of great clinical impact. Severe liver disease in pregnancy is rare; however, pregnancy-related liver disease is the most frequent cause of liver dysfunction during pregnancy and represents a severe threat to foetal and maternal survival. A rapid differential diagnosis between liver disease related or unrelated to pregnancy is required in women who present with liver dysfunction during pregnancy. This report summarizes the recommendation of an expert panel established by the Italian Association for the Study of the Liver (AISF) on the management of liver disease during pregnancy. The article provides an overview of liver disease occurring in pregnancy, an update on the key mechanisms involved in its pathogenesis, and an assessment of the available treatment options. The report contains in three sections: (1) specific liver diseases of pregnancy; (2) liver disease occurring during pregnancy; and (3) pregnancy in patients with pre-existing chronic liver disease. Each topic is discussed considering the most relevant data available in literature; the final statements are formulated according to both scientific evidence and clinical expertise of the involved physicians, and the AISF expert panel recommendations are reported.

Significantly elevated serum lipase in pregnancy with nausea and vomiting: acute pancreatitis or hyperemesis gravidarum?

Hyperemesis gravidarum is a severe manifestation of nausea and vomiting of pregnancy and it is associated with weight loss and metabolic abnormalities. It is known that abnormal laboratory values, including mildly elevated serum lipase level, could be associated with hyperemesis gravidarum. However, in this case report details of two women with hyperemesis gravidarum but with significantly elevated serum lipase levels were discussed. These patients presented with severe nausea and vomiting but without abdominal pain. They were found to have severely elevated lipase levels over 1,000 units/liter. In the absence of other findings of pancreatitis, they were treated with conservative measures for hyperemesis gravidarum, with eventual resolution to normal lipase levels. Although significantly elevated lipase level in pregnant patients with nausea and vomiting is a concern for acute pancreatitis, these two cases of significantly elevated serum lipase without other clinical findings of pancreatitis led to this report that serum lipase could be quite elevated in hyperemesis gravidarum and that it might not be an accurate biochemical marker for acute pancreatitis. Imaging studies are thus necessary to establish the diagnosis of acute pancreatitis.

Hyperemesis gravidarum: current perspectives

Hyperemesis gravidarum is a complex condition with a multifactorial etiology characterized by severe intractable nausea and vomiting. Despite a high prevalence, studies exploring underlying etiology and treatments are limited. We performed a literature review, focusing on articles published over the last 10 years, to examine current perspectives and recent developments in hyperemesis gravidarum.

Evaluation of the maternal-fetal transfer of granisetron in an ex vivo placenta perfusion model

The objective of this study was to estimate maternal-fetal transplacental passage of granisetron in an ex vivo placental perfusion model. Term human placentas (N=8) were collected immediately after delivery. A single cotyledon from each placenta was perfused granisetron concentration to mimic systemic maternal peak plasma concentrations following either IV (50ng/mL) or transdermal administration (5ng/mL). To assess drug transfer and accumulation, samples were collected from maternal and fetal compartments. In the 50ng/mL open model, the mean transport fraction was 0.21±0.08 with clearance index of 0.53±0.66. Fetal peak concentrations achieved was 5.6±6.6ng/mL with mean accumulation of 5.35±6.4ng/mL. No drug was detected in the fetal compartment with the 5ng/mL models. Transplacental passage of granisetron was inconsistent at the 50ng/mL concentration that achieved with IV dosing. However, there consistently was no detectable passage in all the placentas evaluated of the granisetron at 5ng/mL concentration that would be achieved after transdermal patch administration.

Androgens and hyperemesis gravidarum: a case-control study

OBJECTIVE

The pathogenesis of hyperemesis gravidarum (HG) is probably multifactorial, involving several hormones. Androgen concentrations are reported to correlate positively with emesis gravidarum. Hypothesizing a continuum between emesis gravidarum and HG, we investigated androgen concentrations in women with HG.

STUDY DESIGN

In a case-control study, 32 women hospitalized for HG were compared with 29 control women scheduled for elective surgical abortion. Control women were matched for age, gestational length, body mass index (BMI) and parity. Patient characteristics and concentrations of dehydroepiandrosterone sulphate (DHEAS), androstenedione, testosterone, sex hormone binding globulin (SHBG), free testosterone index (FTI), androstanediol glucuronide (ADG), progesterone, TSH, free T3 and T4, beta-hCG, ferritin, insulin, estradiol and estriol were compared using Mann-Whitney tests and multivariate linear regression analyses.

RESULTS

Women with HG had higher concentrations of ADG (8.49±4.19 vs. 6.19±1.77pmol/L; p=0.015), estradiol (2.39±1.36 vs. 1.60±9.30nmol/L; p=0.009) and ferritin (186±138 vs. 117±94pmol/L; p=0.040) compared with control women. Androstenedione (5.34±2.82 vs. 6.86±2.67; p=0.004) and insulin (63.7±35.0 vs. 75.3±25.8; p=0.050) concentrations were lower in women with HG. DHEAS, testosterone, FTI, SHBG, estriol, progesterone, beta-hCG, TSH, free T3 and free T4 concentrations did not differ between the groups. In multivariate regression analyses HG was associated with high concentrations of ADG (p=0.026) and low concentrations of androstenedione (p=0.018).

CONCLUSION

Steroid hormone homeostasis may be altered in women with HG. HG may be associated with high ADG and low androstenedione concentrations.

Regulation of nausea and vomiting by cannabinoids and the endocannabinoid system

Nausea and vomiting (emesis) are important elements in defensive or protective responses that animals use to avoid ingestion or digestion of potentially harmful substances. However, these neurally-mediated responses are at times manifested as symptoms of disease and they are frequently observed as side-effects of a variety of medications, notably those used to treat cancer. Cannabis has long been known to limit or prevent nausea and vomiting from a variety of causes. This has led to extensive investigations that have revealed an important role for cannabinoids and their receptors in the regulation of nausea and emesis. With the discovery of the endocannabinoid system, novel ways to regulate both nausea and vomiting have been discovered that involve the production of endogenous cannabinoids acting centrally. Here we review recent progress in understanding the regulation of nausea and vomiting by cannabinoids and the endocannabinoid system, and we discuss the potential to utilize the endocannabinoid system in the treatment of these frequently debilitating conditions.