Helicobacter pylori Exposure in Nausea and Vomiting of Pregnancy Increases Risk of Preterm Delivery

Table 3

H. pylori status is related to pregnancy outcomes in patients with vomiting in pregnancy. Pregnancy outcomes were correlated to vomiting in pregnancy-related diagnoses, laboratory test results, and demographic features identified in this study. Interaction analysis between diagnosis of vomiting in pregnancy and H. pylori test result within 5 years of pregnancy was performed using multivariate logistic regression models. Interaction of NVP diagnosis and positive HP result correlated to increased risk of preterm delivery in both discovery and validation cohorts. See Figure 1 for a graphical representation of gestational age at delivery. Blue text indicates lower-order effects of NVP or HP in isolation. Interpretation of these is complex due to inclusion of the NVPHP interaction term. An adjusted odds ratio confident interval not including 1 and p values less than 0.05 were considered significant.

	Small for gestational age (z-score< -1.28)		Preterm delivery (<37 weeks)
	Adjusted odds ratio [95% CI]		Adjusted odds ratio [95% CI]
Discovery cohort n 297
Vomiting in pregnancy^†	1.1 [0.3–3.1]	0.9	0.1 [0.0–0.6]	0.04
H. pylori positive^†	0.6 [0.1–1.8]	0.4	0.8 [0.3–1.8]	0.5
NVPHP positive	1.7 [0.3–10.4]	0.6	8.8 [1.0–76]^‡	0.03
Race and ethnicity	0.9 [0.3–2.2]	0.8	1.0 [0.4–2.2]	1.0
Medicaid insurance	0.8 [0.3–2.2]	0.7	1.2 [0.5–2.9]	0.6
Validation cohort (n = 11,995)
Vomiting in pregnancy^†	n.d.		2.4 [1.3-4.3]	0.006
H. pylori positive^†	n.d.		0.6 [0.3–0.9]	0.03
NVPHP positive^‡	n.d.		2.3 [1.3–4.3]	0.02
Obesity/overweight	n.d.		1.6 [1.3–2.1]	<0.001
Multiparity-associated diagnosis	n.d.		3.5 [2.1–5.5]	<0.001
Education, literacy, housing or economic problem	n.d.		3.1 [2.3–4.1]	<0.001
Substance use diagnosis	n.d.		1.1 [0.8–1.4]	0.6
High-risk pregnancy	n.d.		1.1 [0.9–1.3]	0.6

^†Interpretation of lower order effects, NVP or HP in isolation, is complex due to inclusion of the NVPHP interaction term. ^‡Odds ratios reflect the effect of positive HP within the strata of subjects with NVP.