Severity and duration of nausea and vomiting symptoms in pregnancy and spontaneous abortion

Department of Maternal and Child Health, School of Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7435, USA.
Human Reproduction (Impact Factor: 4.57). 11/2010; 25(11):2907-12. DOI: 10.1093/humrep/deq260
Source: PubMed


Earlier studies have shown an inverse association between the presence of nausea and vomiting in pregnancy (NVP) and spontaneous abortion (SAB), but no study to date has examined the effects of symptom duration on the risk of SAB.
We examined NVP symptom severity and duration in relation to the occurrence of SAB. Data were collected from 2407 pregnant women in three US cities between 2000 and 2004 through interviews, ultrasound assessments and medical records abstractions. Discrete-time continuation ratio logistic survival models were used to examine the association between NVP and pregnancy loss.
Lack of NVP symptoms was associated with increased risk for SAB [adjusted odds ratio (OR) = 3.2, 95% confidence interval (CI): (2.4, 4.3)], compared with having any symptoms. Reduced risks for SAB were found across most maternal age groups for those with NVP for at least half of their pregnancy, but the effects were much stronger in the oldest maternal age group [OR = 0.2, 95% CI: (0.1, 0.8)].
The absence of NVP symptoms is associated with an increased risk of early pregnancy loss. As symptom duration decreases, the likelihood of early loss increases, especially among women in the oldest maternal age group.

Full-text preview

Available from:
  • Source
    • "One possibility is that pregnancy sickness is simply an index of embryo quality—e.g., embryos with chromosomal defects cannot manufacture sufficient quantities of the biochemical antecedents of pregnancy sickness to induce nausea and vomiting (Stein and Susser, 1991; Forbes, 2002). Chan et al. (2010) examined the link between pregnancy sickness, spontaneous abortion and maternal age. Intriguingly they found that an absence of pregnancy sickness was a much stronger predictor of spontaneous abortion in mothers over age 35 than for mothers under age 30. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Pregnancy sickness is widespread in human mothers but its etiology, somewhat surprisingly, remains unclear. Human chorionic gonadotropin (hCG) has long been considered a prime hormonal suspect, but the correlation between pregnancy sickness and hCG levels is imperfect resulting in uncertainty about its causal role. As others have noted part of this uncertainty likely stems from the structural and functional diversity of hCG. One enigmatic role of hCG is its action as a thyroid stimulator during early gestation. Native hCG is weakly thyrotropic but is produced in prodigious quantities and suppresses the production of thyroid stimulating hormone (TSH) but not curiously when TSH levels are in the higher deciles. Higher levels of hCG induce higher maternal production of thyroxine (T4). hCG thus appears to augment and sometimes even supplant TSH in the regulation of thyroid hormone in early gestation. This has lead to the suggestion that hCG serves as a backup system, albeit incomplete, for the production of essential thyroid hormone during pregnancy. Another interpretation, however, is that hCG, produced by the embryo, serves as a second control circuit for the thyroid during pregnancy. If so, it serves embryonic interests that are at odds with maternal interests (maternal-embryo conflict) under conditions of iodine deficiency. Iodine is an essential micronutrient for neurodevelopment and thyroid function, and has been in short supply for most humans over most of our evolutionary history. Iodine deficiency during gestation has severe impacts on embryo neuromotor development, but also induces thyroid disease in mothers, impairing her future reproductive prospects. Under this view, embryos use hCG to push mothers to release more thyroid hormone. hCG, however, is produced outside the normal maternal thyroid control circuit and thus is not subject to a normal negative feedback. hCG also serves multiple functions simultaneously therefore its production is likely not fine-tuned for thyroid function per se. hCG levels may remain high even when thyroid hormone production is more than sufficient to meet the needs of mother and embryo. Instead, the system appears to be regulated at the back end by clearing surplus hormone using placental Type II (D2) and Type III (D3) deiodinases. As maternal thyroid hormone levels rise, placental D3 is upregulated, shunting more T4 and T3 into a deactivating pathway. The metabolites that result, particularly the inert metabolite of T4, reverse T3, are correlates of surplus thyroid hormone production and thus are strong candidates for the proximate triggers of pregnancy sickness. Nausea and vomiting of early pregnancy thus arises as a by-product of an antagonistic pleiotropy between mother and embryo over the allocation of iodine: when dietary iodine is scarce, a benefit accrues to the embryo at a cost to mother; when iodine is plentiful, pregnancy sickness ranging from frequently mild to occasionally severe, is a sequelae of undiminished embryonic demands. If pregnancy sickness serves as a marker of thyroid function, an absence of first trimester nausea and vomiting sickness may indicate a higher priority for testing of thyroid function to avert the inimical effects of hypothyroidism during gestation.
    Full-text · Article · Jan 2014 · Journal of Theoretical Biology
    • "The high prevalence of reported anemia is comparable to other hemoglobin-based estimates, although gestational anemia in the present study population was related to hemoglobinopathies rather than iron deficiency [26]. The lower prevalence of morning sickness may be accounted for by the definition requiring both nausea and vomiting in order to increase specificity, whereas many studies use nausea alone to report prevalence rates of 50%–90% [27] . The prevalence of RTIs probably does not reflect sexually transmitted infections, and instead captures women with normal physiologic discharge or endogenous infections such as bacterial vaginosis, which has been associated with preterm labor [28,29]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE: To determine the burden of maternal morbidity in early pregnancy in rural northern Bangladesh. METHODS: A cross-sectional analysis was performed on baseline morbidity data from 42 896 pregnant women enrolled in a vitamin A supplementation trial. One-week histories for 31 defined symptoms were collected at 5-12weeks of gestation. Ten illnesses were defined, compatible with ICD-10 diagnoses and WHO definitions. Prevalence, duration, and treatment-seeking behaviors were determined for each symptom and illness. Risk of wasting malnutrition was compared between symptomatic and asymptomatic women. RESULTS: In total, 93.1% of women reported at least 1 symptom. The most frequent symptoms were poor appetite (53.3%), vaginal discharge (48.7%), and nausea (48.1%), each of which lasted 22-27days. The most prevalent illnesses were anemia (36.4%), morning sickness (17.2%), excessive vomiting (7.0%), and reproductive tract infections (6.7%). Symptoms that prompted treatment seeking included jaundice, high-grade fever, and swelling of hands and face. Odds ratios for malnutrition were higher among women with symptoms of anemia (1.30; 95% confidence interval [CI], 1.24-1.36), vaginal discharge (1.37; 95% CI, 1.31-1.43), and high-grade fever (1.23; 95% CI, 1.10-1.37) than among those without symptoms. CONCLUSION: Women in rural Bangladesh report substantial morbidity in the first trimester.
    No preview · Article · Oct 2012 · International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics

  • No preview · Article · Dec 2010 · The practising midwife
Show more