Emerging Progress in Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum: Challenges and Opportunities

Eliminating gender bias in biomedical research requires fair inclusion of pregnant women and gender diverse people

Systematic under-representation of pregnant women and gender diverse pregnant people in clinical research has prevented them from benefitting fairly from biomedical advances. The resulting lack of pharmacological safety and efficacy data leads to medicine discontinuation, sub-optimal dosing, and reliance on repurposed therapies. We identify four roadblocks to fair inclusion. First, investment and research are inhibited by protectionist attitudes among research gatekeepers who view pregnancy as a vulnerable state. Second, exclusion ignores human-specific biological variations affecting medication absorption and impacts on the pregnant body. Third, pregnant populations in low-and middle-income countries face a double disadvantage due to gender and location, despite bearing a disproportionate maternal mortality burden. Fourth, perspectives and experiences of pregnant populations are undervalued in clinical intervention design. We propose five actions to optimize fair inclusion: fostering reciprocal partnerships, prioritizing multi-disciplinary research, awareness-raising of the need for pharmaceutical innovation, conducting regulatory analyses, and promoting responsible inclusion over presumptive exclusion.

Re-examining the adaptive function of nausea and vomiting in pregnancy

Nausea and vomiting in pregnancy (NVP) have been proposed to have a prophylactic function. In this review, I re-examine NVP from an evolutionary perspective in light of new research on NVP. First, current evidence suggests that the observed characteristics of NVP does not align well with a prophylactic function. Further, NVP is typically associated with high costs for pregnant women, while moderate-to-severe NVP is associated with increased risks of poorer foetal/birth outcomes. In contrast, mild NVP limited to early pregnancy may associate with improved foetal outcomes-indicating a potential evolutionary benefit. Second, researchers have recently identified growth differentiation factor 15 (GDF15) to cause NVP, with implications that low-levels of pre-conception GDF15 (associated with lower cellular stress/inflammation) may increase risks/symptoms of NVP. If so, NVP in contemporary post-industrialized populations may be more severe due to environmental mismatch, and the current symptomology of NVP in such populations should not be viewed as a typical experience of pregnancy.

Pregnancy outcomes by hyperemesis gravidarum severity and time of diagnosis: A retrospective cohort study

OBJECTIVE

With inconsistencies regarding the possible effect of hyperemesis gravidarum on the course of pregnancy, this research aimed to study the association between hyperemesis gravidarum and pregnancy outcomes, while also addressing the trimester of diagnosis and severity.

METHODS

A retrospective cohort study was performed, including all singleton deliveries of mothers from the largest health maintenance organization in the country, in a single tertiary hospital between 1991 and 2021. The incidence of adverse pregnancy outcomes was compared between pregnancies with and without hyperemesis gravidarum diagnosis. Multivariable generalized estimation equation binary models were used to study the association between maternal hyperemesis gravidarum, trimester of diagnosis and hyperemesis gravidarum severity and the studied outcomes.

RESULTS

The study population included 232 476 pregnancies, of which 3227 (1.4%) were complicated with hyperemesis gravidarum. Women with hyperemesis gravidarum were more likely to deliver preterm (adj. OR = 1.33, 95% CI: 1.18-1.50), a newborn with low birthweight (adj. OR = 1.52, 95% CI: 1.16-1.98, only if diagnosed in the second trimester), and to have a cesarean delivery (adj. OR = 1.20, 95% CI: 1.09-1.32). They were less likely to deliver small gestational age newborn (adj. OR = 0.82, 95% CI: 0.69-0.99) and their offspring to experience perinatal mortality (adj. OR = 0.54, 95% CI: 0.31-0.93, among mild cases only). A dose-response association was observed between preterm birth and hyperemesis gravidarum (adj. OR = 1.26; 95% CI: 1.11-1.44, for mild cases and adj. OR = 2.04; 95% CI: 1.31-3.19, for severe cases).

CONCLUSIONS

Hyperemesis gravidarum is associated with an increased risk for adverse pregnancy outcomes including mainly preterm delivery in a dose-response manner and when diagnosed during the second trimester.

[Hyperemesis Gravidarum - an Interprofessional and Interdisciplinary Challenge - Evidence-Based Review]

Hyperemesis gravidarum (HG) is a multifactorial disease characterized by severe and persisting nausea and vomiting, impairment of oral intake, weight loss of at least 5%, electrolyte abnormalities, and dehydration. The prevalence of HG ranges from 0.3 to 10% worldwide. The diagnosis is made by the patient's prehistory, clinical symptoms, physical examination, and the typical laboratory abnormalities. Therapeutic cornerstones are nutrition advice, consultation of life style, psychological/psychosocial support of the mother as well as the administration of antiemetics in a stepwise approach, depending on the severity of symptoms, and finally admission to hospital in severe cases. Treatment of patients requires close interprofessional and interdisciplinary cooperation.

Nausea, vomiting and conflict in pregnancy: The adaptive significance of Growth-Differentiation Factor 15

Nausea and vomiting in pregnancy (NVP) is heritable, common and aversive, and its extreme, hyperemesis gravidarum (HG), can be highly deleterious to the mother and fetus. Recent influential studies have demonstrated that HG is caused predominantly by high levels of Growth-Differentiation Factor 15 (GDF15), a hormone produced by the placenta in substantial amounts. This work has led to calls for therapeutic modulation of this hormone to reduce GDF15 levels and ameliorate HG risk. I describe three main lines of evidence relevant to the hypothesis that GDF15 production is typically adaptive for the fetus, in the context of enhanced placental invasion, reduced rates of miscarriage and preterm birth and higher birth weight. These considerations highlight the medical implications of maternal-fetal conflict, in the context of tradeoffs between aversive symptoms during gestation, rare disorders of pregnancy with major adverse effects and moderate fitness-enhancing benefits to fetuses.

Efficacy and safety of acupressure in nausea and vomiting during pregnancy: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety of acupressure on nausea and vomiting during pregnancy.

METHODS

PubMed, Embase, Springer, Web of Science, and the Cochrane Library were searched for all randomized controlled trials (RCT) of treating nausea and vomiting during pregnancy by acupressure from the inception date of database to July 31st, 2023. Study selection, data extraction, and risk of bias assessment were conducted independently by researchers. The methodological quality of included studies was evaluated by the Cochrane Collaboration's bias risk assessment tool, meta-analysis by Stata 17.0 software, and publication bias by Begg's test.

RESULTS

A total of 11 RCTs involving 1378 pregnant women were included in this review, which was assessed to be moderate quality. 10 RCTs involving 1298 pregnant women were assessed for the meta-analysis. The results revealed that acupressure showed significant difference on improvement in symptom score compared with sham acupressure (pooled MD, - 1.33; 95%CI [- 2.06, - 0.61]; P < 0.001) or control group (pooled MD, - 0.73; 95%CI [- 1.08, - 0.39]; P < 0.001), and incidence of effective rate compared with sham acupressure group (pooled RR, 1.78; 95%CI [1.03, 3.07]; P = 0.039). However, no statistical significance was found between acupressure and control group (pooled RR, 4.53; 95%CI [0.67, 30.48]; P = 0.120) on effective rate. On comparing acupressure with sham acupressure, there was no beneficial effect on preventing nausea and vomiting during pregnancy (pooled RR, 0.83; 95%CI [0.50, 1.38]; P = 0.476), shortening the duration of hospital stay (pooled MD, - 0.78; 95%CI [- 1.98, 0.41]; P = 0.199) and improving patient satisfaction (pooled RR, 1.36; 95%CI [0.47, 3.91]; P = 0.570). Begg's test did not reveal any publication bias. Only one RCT reported minimal acupressure-related adverse events.

CONCLUSION

Acupressure may have potential favorable or encouraging effect on treating nausea and vomiting during pregnancy, but strong supportive data are not yet available. Well-designed and large-scale RCTs should be conducted for assessing and confirming the efficacy and safety of acupressure in nausea and vomiting during pregnancy.

The Relationships Between Multidimensional Symptom Burden, Adaptation, and Depression During Pregnancy: A Cross-sectional Study

Prenatal depression is highly prevalent, but its relationship with the multidimensional burden of physical symptoms during pregnancy remains underexplored. The aim of this study was to examine the relationship between pregnancy-related physical symptom burden, including frequency, severity, and impact on life and pregnancy adaptation to prenatal depression, and to identify predictors of depression during pregnancy. The study was cross-sectional in design. A hospital-based setting providing comprehensive maternity care services from outpatient to inpatient. The sample consisted of two hundred forty-three pregnant individuals aged 20 and above with no major obstetrical complications. Structured questionnaires including demographic and obstetrical characteristics, depression, symptom burden, and pregnancy adaptation were used for data collection. Multiple linear regression analyses were performed to identify significant predictors of depression. The study revealed that approximately 32% of the variance in depression scores could be explained by the combined effects of pregnancy-related physical symptom burden and pregnancy adaptation. Specifically, low-level pregnancy adaptation, high-level symptom impact on life, unmarried status, and mid-level symptom severity were identified as the main predictors of prenatal depression among low-risk pregnant individuals. The findings contribute to the existing knowledge base, emphasizing the significance of addressing and managing pregnancy-related physical symptom burden while promoting effective adaptation to pregnancy as a means to mitigate the risk of prenatal depression.

The efficacy and safety of acupuncture and moxibustion for the management of nausea and vomiting in pregnant women: A systematic review and meta-analysis

Background

Nausea and vomiting, which cause considerable multifaceted effects, are commonly experience in early pregnancy. Various therapeutic strategies are employed, including both conventional agents and complementary medicine. However, the effectiveness of complementary medicine remains controversial. The objective of this meta-analysis is to evaluate efficacy and safety of acupuncture and moxibustion in pregnant women.

Methods

We conducted a comprehensive search using electronic databases such as PubMed, Embase, ISI Web, Medline, Cochrane, clinicaltrial.gov, and several Chinese databases. A total of 21 randomized controlled trials were included in this study for quantitative analysis. Forest plots were utilized to evaluate the efficacy and safety of acupuncture and moxibustion. Egger's test was employed to assess publication bias.

Results

The pooled analysis revealed that the acupuncture/moxibustion group was more effective than control group in alleviating nausea and vomiting in early pregnant women (RR: 0.28; 95%CI: 0.21, 0.37). Similar results were observed when comparing the acupuncture group to traditional herbs (RR: 0.08; 95 % CI: 0.01, 0.60), conventional therapy (RR: 0.15; 95 % CI: 0.04, 0.57), and the blank control group (RR: 0.33; 95 % CI: 0.22, 0.51). Moxibustion also exhibited the ability to alleviate nausea and vomiting compared with the blank control group (RR: 0.21; 95 % CI: 0.08, 0.52). As for safety, there were no significant differences in severe adverse events between the acupuncture group and the control group (RR: 0.77; 95%CI: 0.52, 1.14), the blank control group (RR: 0.61; 95%CI: 0.34, 1.10), the sham acupuncture group (RR: 1.05; 95%CI: 0.63, 1.73), or the conventional therapy group (RR: 0.32; 95%CI: 0.06, 1.55).

Conclusion

Acupuncture and moxibustion might be effective for the management of nausea and vomiting in early pregnant women. Moreover, acupuncture might be a relatively safe treatment for pregnancy.

The association between Helicobacter pylori and gastrointestinal disorders during pregnancy: A Multicenter retrospective study

BACKGROUND

Some gastrointestinal disorders may be associated with Helicobacter pylori infection, which not only affect maternal health, but may also lead to adverse pregnancy outcomes. We aim to explore the association between H. pylori and gastrointestinal disorders in pregnant women.

MATERIALS AND METHODS

In total, 503 patients were retrospectively analyzed and divided into the H. pylori-uninfected group, the H. pylori-infected group, or the H. pylori-eradicated group. We analyzed the influence of H. pylori on gastrointestinal diseases during pregnancy among the groups, as well as the severity, symptoms, laboratory tests of the H. pylori-related diseases.

RESULTS

Pregnant women with H. pylori infection had higher risk of nausea and vomiting of pregnancy (NVP) (p < 0.001), severe NVP(p = 0.012), hyperemesis gravidarum (p = 0.027), hematemesis (p = 0.018), hyponatremia (p = 0.033), as well as functional dyspepsia symptoms including epigastric pain (p = 0.004), bloating (p = 0.024), and feeling full quickly in a meal (p = 0.031) compared with those without H. pylori infection. While the prevalence of NVP (p = 0.024), severe NVP (p = 0.009), epigastric pain (p = 0.037), and bloating (p = 0.032) were lower in H. pylori-eradicated pregnant women than in H. pylori-infected women. In addition, pregnant women with H. pylori infection had higher risk of spontaneous preterm birth than whom without H. pylori infection (p = 0.033).

CONCLUSIONS

Helicobacter pylori infection was associated with higher risks of NVP, severe NVP, hyperemesis gravidarum, functional dyspepsia, and spontaneous preterm birth in pregnant women.

Therapeutic health effects of ginger (Zingiber officinale): updated narrative review exploring the mechanisms of action

Ginger (Zingiber officinale) has been investigated for its potentially therapeutic effect on a range of chronic conditions and symptoms in humans. However, a simplified and easily understandable examination of the mechanisms behind these effects is lacking and, in turn, hinders interpretation and translation to practice, and contributes to overall clinical heterogeneity confounding the results. Therefore, drawing on data from nonhuman trials, the objective for this narrative review was to comprehensively describe the current knowledge on the proposed mechanisms of action of ginger on conferring therapeutic health effects in humans. Mechanistic studies support the findings from human clinical trials that ginger may assist in improving symptoms and biomarkers of pain, metabolic chronic disease, and gastrointestinal conditions. Bioactive ginger compounds reduce inflammation, which contributes to pain; promote vasodilation, which lowers blood pressure; obstruct cholesterol production, which regulates blood lipid profile; translocate glucose transporter type 4 molecules to plasma membranes to assist in glycemic control; stimulate fatty acid breakdown to aid weight management; and inhibit serotonin, muscarinic, and histaminergic receptor activation to reduce nausea and vomiting. Additional human trials are required to confirm the antimicrobial, neuroprotective, antineoplastic, and liver- and kidney-protecting effects of ginger. Interpretation of the mechanisms of action will help clinicians and researchers better understand how and for whom ginger may render therapeutic effects and highlight priority areas for future research.

Dietary Intake and Its Association with Birth Outcomes in Women with Nausea and Vomiting during the Second Trimester of Pregnancy: A Prospective Cohort Study in Japan

Nausea and vomiting in pregnancy (NVP) is a common symptom. Although the influence of NVP during the first trimester on dietary intake and birth outcomes has been revealed, no study has focused on NVP during the second trimester. This study aimed to reveal whether NVP severity during the second trimester is associated with dietary intake, gestational weight gain (GWG), birth weight, and delivery week. Participants completed a questionnaire at 18-27 gestational weeks. NVP severity was assessed using the modified Pregnancy-Unique Quantification of Emesis and Nausea scale in the questionnaire. Dietary habits were assessed using a brief-type diet history questionnaire. In total, 825 responses were analyzed: 202 (24.5%), 135 (16.4%), and 8 (1.0%) women reported mild, moderate, and severe NVP, respectively; 480 (58.2%) women did not have NVP during the second trimester. No significant association was observed between energy and nutrient intake and no/mild and moderate/severe NVP. Women with moderate/severe NVP had lower total GWG than those with no/mild NVP (p = 0.007). There was no significant difference in low birth weight and preterm birth rates (p = 0.246 and p = 0.604). This is the first study to investigate whether NVP severity during the second trimester is associated with dietary intake and birth outcomes.

Maternal hepatic immunology during pregnancy

The liver plays pivotal roles in immunologic responses, and correct hepatic adaptations in maternal immunology are required during pregnancy. In this review, we focus on anatomical and immunological maternal hepatic adaptations during pregnancy, including our recent reports in this area. Moreover, we summarize maternal pregnancy-associated liver diseases, including hyperemesis gravidarum; intrahepatic cholestasis of pregnancy; preeclampsia, specifically hemolysis, elevated liver enzymes, and low platelet count syndrome; and acute fatty liver of pregnancy. In addition, the latest information about the factors that regulate hepatic immunology during pregnancy are reviewed for the first time, including human chorionic gonadotropin, estrogen, progesterone, growth hormone, insulin like growth factor 1, oxytocin, adrenocorticotropic hormone, adrenal hormone, prolactin, melatonin and prostaglandins. In summary, the latest progress on maternal hepatic anatomy and immunological adaptations, maternal pregnancy-associated diseases and the factors that regulate hepatic immunology during pregnancy are discussed, which may be used to prevent embryo loss and abortion, as well as pregnancy-associated liver diseases.

Bioavailability of Cariban® Capsules: A Modified-Release Fixed-Dose Combination of Doxylamine and Pyridoxine to Relieve Nausea and Vomiting During Pregnancy

BACKGROUND

Nausea and vomiting is a very prevalent condition during pregnancy. Combination of doxylamine and pyridoxine is placed as first-line pharmacological option for its treatment in most clinical guidelines. Among different release forms available, Cariban® is a fixed-dose combination of doxylamine/pyridoxine 10/10 mg, formulated as modified-release capsules.

OBJECTIVES

In the present study, we aimed to characterize the bioavailability performance of Cariban® in vitro and in vivo.

METHODS

An in vitro dissolution test was performed to evaluate the release profile of Cariban®, together with immediate- and delayed-release formulations available on the market. A single-center, single-dose, open-label bioavailability study following Cariban® administration in 12 healthy adult female patients was carried out to explore the drug behavior in vivo (protocol NBR-002-13; EUDRA-CT 2013-005422-35). These data were additionally used to perform a computational pharmacokinetic simulation of the posology approved for this drug.

RESULTS

Cariban® capsules demonstrate a prolonged-release performance, with an early, gradual, and progressive release of both actives until reaching a complete dissolution after 4-5 h in solution. The pharmacokinetic features of these capsules show that doxylamine and pyridoxine metabolites are early absorbed, being all detectable in plasma within 1 h following oral administration. Computational pharmacokinetic simulation predicts that different posology provides distinct profiles of metabolites in plasma, with 1-1-2 (morning-midafternoon-night) being the one that concentrates higher plasma levels but lower dose dumping for 24 h.

CONCLUSION

Cariban® behaves as a prolonged-release formulation, which correlates with rapid absorption and arising of the actives in the plasma, but also long-lasting and sustained bioavailability, especially when administered following the complete posology. These results would underlie its demonstrated efficacy to relieve nausea and vomiting of pregnancy (NVP) under clinical settings.

Psychologic Sequelae in Early Pregnancy Complications

Early pregnancy complications, including miscarriage, ectopic pregnancies, and hyperemesis gravidarum, are common discomforts accounting for about 15% to 20% of all pregnancies. A proportion of women with early pregnancy complications will experience short- and long-term psychologic sequelae in the aftermath of pregnancy complications, including anxiety, depression, and post-traumatic stress disorder (PTSD) which are the most commonly reported psychologic reactions. This review will focus on the course and impact of these psychologic sequelae in early pregnancy complications, and the noninvasive interventions to improve mental health are also briefly discussed.

Anti-emetic effects of thalidomide: Evidence, mechanism of action, and future directions

The rationale for using thalidomide (THD) as a treatment for nausea and vomiting during pregnancy in the late 1950s appears to have been based on its sedative or hypnotic properties. In contrast to contemporaneous studies on the anti-emetic activity of phenothiazines, we were unable to identify publications reporting preclinical or clinical evaluation of THD as an anti-emetic. Our survey of the literature revealed a clinical study in 1965 showing THD reduced vomiting in cancer chemotherapy which was substantiated by similar studies from 2000, particularly showing efficacy in the delayed phase of chemotherapy-induced nausea and vomiting. To identify the mechanism(s) potentially involved in thalidomide's anti-emetic activity we reviewed its pharmacology in the light of nausea and vomiting mechanisms and their pharmacology with a particular emphasis on chemotherapy and pregnancy. The process identified the following potential mechanisms: reduced secretion of Growth Differentiation Factor 15, suppression of inflammation/prostaglandin production, downregulation of cytotoxic drug induced upregulation of iNOS, and modulation of BK (KCa1.1) channels and GABAA/glutamate transmission at critical points in the emetic pathways (nucleus tractus solitarius, area postrema). We propose ways to investigate these hypothesized mechanisms and discuss the associated challenges (e.g., objective quantification of nausea) in addition to some of the more general aspects of developing novel drugs to treat nausea and vomiting.

The role of serum ADAMTS-1 levels in Hyperemesis Gravidarum

Background

We aimed to investigate the levels of ADAMTS-1, which is secreted from the extracellular matrix during trophoblastic invasion in hyperemesis gravidarum (HEG).

Methods

In this cross-sectional study, we compared 45 HEG patients aged between 21 and 34 in terms of ADAMTS-1 levels with a control group consisting of 44 healthy pregnant women. The demographic characteristics and several laboratory parameters of the patients were recorded. Both groups were also compared in terms of ketonuria. We evaluated the correlation between ADAMTS-1 levels and ketonuria.

Results

The 2 groups were matched in terms of age, gestational age, gravidity, parity, and body mass index. Some inflammatory markers, such as neutrophil count, MPV, PDW, and PCT levels, were significantly higher in the HEG groups compared to the control group (all p < 0.05). However, mean MCV and serum TSH levels were statistically significantly lower in this group (both p < 0.001). ADAMTS-1 levels were 12.6 ± 1.4 ng/ml in the HEG group and 6.2 ± 1.6 ng/ml in the control group (p < 0.001). It was significantly and positively correlated with urine ketone, neutrophil count, and PDW, whereas negatively correlated with MCV and TSH value in the HEG group. ROC analysis showed that a threshold value of 11.275 ng/ml for ADAMTS-1 predicted HEG patients with a sensitivity of 60% and specificity of 95.5%.

Conclusion

ADAMTS-1 serum levels are increased in HEG patients, and there is a positive correlation between ADAMTS-1 levels and ketonuria.