Nausea and
vomiting in early pregnancy affects 50-80% of pregnant women. Researchers have
linked its etiology to imbalance in carbohydrate metabolism, rising hormonal
levels in pregnancy, psychosomatic factors
evolutionary survival adaptation which protects pregnant mothers and
their babies from food poisoning.
Few observational studies in the past have documented that
incidence of pregnancy loss is lower in patients who have morning sickness in
first trimester.
A new study
published in the in the journal JAMA Internal Medicine[1]
found that women who suffer from nausea and vomiting in the first trimester
have 50% less chance of miscarriage.
The study is
a result of secondary data analysis of a Randomized Control Trial (RCT)
examining Effects of Aspirin in Gestation and Reproduction (EAGeR) Trial.[2]
The EAGeR study is a multi-site, double-blinded randomized trial designed to
assess the effects of low-dose aspirin on implantation and pregnancy outcome
carried out by researchers at NIH's Eunice Kennedy Shriver National
Institute of Child Health and Human Development (NICHD) and other institutions.
The
secondary analysis was limited to women who had a pregnancy confirmed by
positive human chorionic gonadotropin (hCG) test, had a history of at least one
pregnancy loss. A total of 797 study subjects was recruited. The women kept a daily
diary for nausea and vomiting from week 2 to week 8 of pregnancy, and monthly
thereafter.
Out of 797
pregnancies, 188 ended in loss (23.6%), and at the end of 8 weeks about 57.3
percent of the women reported experiencing nausea and 26.6 percent reported
nausea with vomiting.
In this
cohort of women, it was seen that nausea alone or nausea with vomiting during
pregnancy were associated with nearly 50%-75% reduction in the risk for
pregnancy loss. When the analysis was done for peri-implantation pregnancy
loss, the results were similar but they were not statistically significant.
Younger women
(age <25 years) suffered much more with nausea and vomiting as compared to older
women.
The
association persisted even after accounting for confounding factors like maternal
stress, alcohol intake, caffeine intake, smoking, fetal sex, multiple-fetal
gestation, and karyotype.
Stefanie
Hinkle, the lead author and a researcher at the national institute said "Our
study evaluates symptoms from the earliest weeks of pregnancy, immediately
after conception, and confirms that there is a protective association between
nausea and vomiting and a lower risk of pregnancy loss.” But, was not sure
whether the study results could be applied to primigravida.
She also
went to stress that women with no nausea or vomiting should not be alarmed as a
result of this study. "Every pregnancy is different and just because they
don't have symptoms doesn't mean they're going to have a pregnancy loss,"
Hinkle said.[3]
The study
was also followed by an accompanying editorial by Siripanth Nippita, MD, and
Laura E. Dodge, ScD, MPH, from the Department of Obstetrics and Gynecology,
Beth Israel Deaconess Medical Center. They said "This study's contribution
to the existing literature is valuable for several reasons. It builds on a
prior cohort study by Sapra et al and similarly enrolled a large sample of
women before conception."
They further
quote “The widespread availability of sensitive urine hCG tests coupled with
real-time electronic data capture using mobile phone apps or similar technology
has the potential to improve data quality and eliminate recall bias. Given
these methodologic advantages over previous investigations, we hope that such
studies can further deepen our understanding of the underlying causes of
[nausea and vomiting in pregnancy]."
The researchers
also urged women with nausea and vomiting in pregnancy to seek medical
consultation since it negatively affects the quality of life.
[1] http://archinte.jamanetwork.com/article.aspx?articleid=2553283
[2] http://grantome.com/grant/NIH/ZIA-HD008795-08
[3] Stefanie
N. Hinkle, Sunni L. Mumford, Katherine L. Grantz, Robert M. Silver, Emily M.
Mitchell, Lindsey A. Sjaarda, Rose G. Radin, Neil J. Perkins, Noya Galai,
Enrique F. Schisterman.
Association of Nausea and Vomiting During
Pregnancy With Pregnancy Loss.
JAMA Internal Medicine, 2016;
DOI:
10.1001/jamainternmed.2016.5641
