Relationship between Gestational Hypertension and High Birth Weight, in the State of Guanajuato, Mexico

Abstract

Hypertensive disease is one of the main concerns during pregnancy. It is classified as gestational hypertension, preeclampsia, and eclampsia. The objective of this study was to analyze whether there is a relationship between gestational hypertension and high birth weight (≥3500 g) in newborns. It was designed a retrospective quantitative study, considering women admitted for obstetric resolution and their products treated in hospitals from Guanajuato State, Mexico, with hypertension developing after 20 weeks of pregnancy. The Chi-squared test was performed to show a relationship between gestational hypertension and preeclampsia-eclampsia with the newborn's birth weight. Then calculated the effect of gestational hypertension on birthweight by computing the corresponding Odds Ratios (OR). We also fitted a multivariate logistic regression model that included age group, marital status, number of previous pregnancies, and gestational age as covariates. It was computed the Pearson correlation and adjusted a linear regression model to identify the relationship between systolic and diastolic pressure with birthweight. The alpha value was fixed at .05 as a threshold for statistical significance. The number of reviewed registries was 1,675. For the variables age, gestational age at hospital admission, systolic and diastolic blood pressure, and birth weight of the products, there are differences between the groups of mothers (P<.05). For the logistic regression model just including gestational hypertension as covariable, the OR was 1.28 (95% CI=1.0 to 1.63). The gestational age plays a confounding role -other variables did not improve the model-. Systolic and diastolic blood pressure showed a statistically significant (P=0.2, P=0.048) low negative correlation (r=-0.07, r=-0.06) with birth weight for women with gestational hypertension. There is an effect between gestational hypertension and high birth weight, although the effect is confounded by gestational age at birth time. Linear regression between systolic-diastolic pressure and birthweight supports this association. The evidence is low and further studies are advisable.