Association between vomiting in the first trimester and preterm birth: a retrospective birth cohort study in Wuhan, China

Abstract

ObjectiveAlthough vomiting in the first trimester has been reported to be associated with preterm birth (PTB), findings supporting this association remain inconsistent. Our aim was to assess the association between vomiting and PTB, as well as evaluate if the association is modified by pre-pregnancy body mass index (BMI).DesignA retrospective cohort study.SettingWuhan, a central city of China.ParticipantsA total of 317 463 pregnant women who had a live, singleton newborn from 1 January 2010 to 23 May 2016 were enrolled in our study.Main outcome measurePTB was defined as gestational age <37 gestational weeks. Gestational age was calculated using reports from mothers based on the first day of their last menstrual period. An ultrasound was routinely used to determine gestational age before 12 gestational weeks.ResultsOf the 317 463 pregnant women, 29.88% (94 857) experienced vomiting in the first trimester and 5.00% (15 889) experienced a PTB. Vomiting in the first trimester increased the risk for PTB and the multivariable adjusted OR was 1.05 (95% CI 1.02 to 1.09). In the stratified analyses, the association of vomiting in the first trimester was significant among underweight women (adjusted OR=1.08, 95% CI 1.04 to 1.17) and normal pre-pregnancy BMI women (adjusted OR=1.06, 95% CI 1.02 to 1.11), but not in overweight women (adjusted OR=1.01, 95% CI 0.90 to 1.14) and obese women (adjusted OR=0.93, 95% CI 0.73 to 1.19).ConclusionsOur study indicates that vomiting in the first trimester was associated with PTB. Additionally, women with underweight and normal pre-pregnancy BMI who experienced vomiting are more likely to have a PTB.

Nausea, vomiting and poor appetite during pregnancy and adverse birth outcomes in rural Nepal: an observational cohort study

“…However, no studies to date have examined the effect of nausea, vomiting or poor appetite during pregnancy on preterm birth in a low-income, rural setting as in this study. (4,23,25,28,29) The present study showed a cumulative incidence of nausea, vomiting or poor appetite of 60.6% during the rst trimester, which is on the lower end of what has been previously reported. (1,5) Previous literature has shown that nausea and vomiting during pregnancy is less likely to be reported among Asian and African populations as compared to Caucasian populations and the cumulative incidence in the current study agrees with previously reported numbers from Bangladesh and Tanzania.…”

“…(12,24) Nausea and vomiting, in particular severe vomiting such as in hyperemesis gravidarum, has been linked to inadequate weight gain and potentially even weight loss. (12,13,16,17,25) If we had information on weight at the start of pregnancy, we might also have been able to detect weight loss and, with that, potentially detect hyperemesis gravidarum in the enrolled women. Future studies should attempt to design data collection so that it allows for pre-pregnancy or early rst trimester BMI and weight to be collected.…”

“…Nausea and vomiting has been associated with lower-than-recommended weight gain in pregnancy, which in turn has been associated with small for gestational age infants (SGA) and prematurity. (9,12,24,25) SGA is considered a measure of intrauterine growth restriction, as genetic differences in birth size are relatively small in healthy pregnancies. (26) The strength of association of nausea and vomiting in pregnancy with SGA, LBW and preterm birth are inconsistent in the literature.…”

Nausea, vomiting and poor appetite during pregnancy and adverse birth outcomes in rural Nepal: an observational cohort study

“…Equivocal results around preterm birth have been observed in previous studies, however, no studies to date have examined the effect of NVP during pregnancy on preterm birth in a low-income, rural setting as in this study. (4,17,19,23,24) The present study showed a prevalence of NVP of 60.6% during the first trimester, which is on the lower end of what has been previously reported. (1, 5) Previous literature has shown that NV during pregnancy is less likely to be reported among Asian and African populations as compared to Caucasian populations and the prevalence in the current study agrees with previously reported prevalence rates from Bangladesh and Tanzania.…”

“…NV has been associated with lower-than-recommended weight gain in pregnancy, which in turn has been associated with small for gestational age infants (SGA) and prematurity. (9,16,18,19) SGA is considered a measure of intrauterine growth restriction, as genetic differences in birth size are relatively small in healthy pregnancies. (20) The strength of association of NV of pregnancy with SGA, LBW and preterm birth are inconsistent in the literature.…”