Increasing nausea and vomiting of pregnancy is associated with sex-dependent differences in early childhood growth: the GUSTO mother-offspring cohort study

Hyperemesis gravidarum theories dispelled by recent research: a paradigm change for better care and outcomes

Nausea and vomiting (NVP) affect most pregnant women. At the severe end of the clinical spectrum, hyperemesis gravidarum (HG) can be life-threatening. The condition is fraught with misconceptions that have slowed progress and left women undertreated. Herein, recent scientific advances are presented that dispel common myths associated with HG related to maternal/offspring outcomes, etiology, and evolution. There is now strong evidence that (i) HG is associated with poor outcomes, (ii) a common cause of NVP and HG has been identified, and (iii) NVP is likely a protective evolutionary mechanism that occurs throughout the animal kingdom but is no longer necessary for human survival. Therefore, it is encouraging that we are finally on the cusp of testing treatments that may put an end to unnecessary suffering.

Perinatal outcomes of infants born to mothers with hyperemesis gravidarum: A systematic review and meta-analysis

BACKGROUND

Hyperemesis gravidarum is the severe form of nausea and vomiting during pregnancy and can lead to undernutrition and low maternal weight gain. Previous epidemiologic and animal studies have shown that undernutrition and low maternal weight gain in pregnancy can increase the risk of unfavorable perinatal outcomes, like shorter gestational age, small for gestational age and lower weight at birth.

OBJECTIVE

To evaluate the effect of hyperemesis gravidarum on perinatal outcomes.

SEARCH STRATEGY

OVID Medline and Embase were searched from inception to February 9th, 2022.

STUDY ELIGIBILITY

Studies reporting on perinatal outcomes of infants born to mothers with hyperemesis gravidarum or severe nausea and vomiting in pregnancy were included. Case reports, case series, animal studies, reviews, editorials and conference abstracts were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected and extracted data. Risk of bias was assessed by the Newcastle-Ottawa Quality Assessment Scale. We conducted meta-analyses where possible.

RESULTS

Our search yielded 1387 unique papers, of which 61 studies (n = 20,532,671 participants) were included in our systematic review. Meta-analyses showed that hyperemesis gravidarum was associated with preterm birth < 34 weeks (2 studies n = 2,882: OR 2.81, 95 %CI: 1.69-4.67), birth weight < 1500 g (2 studies, n = 489,141: OR 1.43, 95 %CI: 1.02-1.99), neonatal resuscitation (2 studies, n = 4,289,344: OR 1.07, 95 %CI: 1.05-1.10), neonatal intensive care unit admission (7 studies, n = 6,509,702: OR 1.20, 95 %CI: 1.14-1.26) and placental abruption (6 studies, n = 9,368,360: OR 1.15, 95 %CI: 1.05-1.25). Hyperemesis gravidarum was associated with reductions in birthweight > 4000 g (2 studies, n = 5,503,120: OR 0.74, 95 %CI: 0.72-0.76) and stillbirth (9 studies, n = 3,973,154: OR 0.92, 95 %CI: 0.85-0.99). Meta-analyses revealed no association between hyperemesis gravidarum and Apgar scores < 7 at 1 and 5 min; fetal loss, perinatal deaths and neonatal deaths.

CONCLUSION

Hyperemesis gravidarum is associated with several adverse perinatal outcomes including low birth weight and preterm birth. We also found that pregnancies complicated by hyperemesis gravidarum less frequently were complicated by macrosomia and stillbirth. We were unable to investigate underlying mechanisms.

Long-term health outcomes of children born to mothers with hyperemesis gravidarum: a systematic review and meta-analysis

OBJECTIVE

Hyperemesis gravidarum is characterized by severe nausea and vomiting in pregnancy, frequently resulting in severe maternal nutritional deficiency. Maternal undernutrition is associated with adverse offspring health outcomes. Whether hyperemesis gravidarum permanently affects offspring health remains unclear. This review aimed to evaluate the effects of maternal hyperemesis gravidarum on offspring health.

DATA SOURCES

MEDLINE and Embase were searched from inception to September 6, 2021.

STUDY ELIGIBILITY CRITERIA

Studies reporting on health at any age beyond the perinatal period of children born to mothers with hyperemesis gravidarum were included.

METHODS

Two reviewers independently selected studies and extracted data. The Newcastle-Ottawa Quality Assessment Scale was used to assess risk of bias. We conducted a narrative synthesis and meta-analysis where possible. In meta-analyses with high heterogeneity (I²>75%), we did not provide a pooled odds ratio.

RESULTS

Nineteen studies were included in this systematic review (n=1,814,785 offspring). Meta-analysis (n=619, 2 studies: 1 among adolescents and 1 among adults) showed that hyperemesis gravidarum was associated with anxiety disorder (odds ratio, 1.74; 95% confidence interval, 1.04-2.91; I², 0%) and sleep problems in offspring (odds ratio, 2.94; 95% confidence interval, 1.25-6.93; I², 0%). Hyperemesis gravidarum was associated with testicular cancer in male offspring aged up to 40 years on meta-analysis (5 studies, n=20,930 offspring), although heterogeneity was observed on the basis of a wide 95% prediction interval (odds ratio, 1.60; 95% confidence interval, 1.07-2.39; I², 0%; 95% prediction interval, 0.83-3.08). All 6 studies reporting on attention deficit (hyperactivity) disorder and autism spectrum disorder reported an increase among children of mothers with hyperemesis gravidarum in comparison with children of unaffected mothers. Meta-analysis showed high heterogeneity, precluding us from reporting a pooled odds ratio. Most studies reporting on cognitive and motor problems found an increase among hyperemesis gravidarum-exposed children. One study investigated brain structure and found smaller cortical volumes and areas among children from hyperemesis gravidarum-affected pregnancies than among those from unaffected pregnancies. Studies evaluating anthropometry and cardiometabolic disease risk of hyperemesis gravidarum-exposed children had inconsistent findings.

CONCLUSION

Our systematic review showed that maternal hyperemesis gravidarum is associated with small increases in adverse health outcomes among children, including neurodevelopmental disorders, mental health disorders, and possibly testicular cancer, although evidence is based on few studies of low quality.