Hyper-Hypo study: A Retrospective Observational Study of Neonatal Hypoglycemia Related to Maternal Hypertension

Objective

The study aims to identify and evaluate the relationships between unmodifiable and potentially modifiable factors in hypoglycemic neonates with hypertensive mothers. 

Design

This was a retrospective observational analysis of routinely collected anonymized data related to neonatal hypoglycaemia and maternal hypertension. 

Method

The study was carried out at the tertiary Neonatal Intensive Care Unit (112 beds) of the Women’s Wellness and Research Center of Hamad Medical Corporation, Doha, Qatar. This study included all neonates admitted into the NICU diagnosed with neonatal hypoglycemia with a maternal history of antihypertensive therapy use during pregnancy. This research described the prevalence of neonatal hypoglycaemia related to use of antihypertensive drugs for maternal hypertension. The identified modifiable risks can be used to improve neonatal practice and support future policy developments to ensure optimal neonatal outcomes. 

Results

We examined 1197 out of 1199 neonates admitted into NICU with a diagnosis of hypoglycemia. About 78% (n=862) of the neonates were admitted primarily due to hypoglycemia, with a mean initial blood glucose reading of 1.9 ± 0.8 mmol\L upon admission. About 28.3% of neonates(n=339) were born to mothers with hypertensive disorders in pregnancy, and 49.0% neonates of diabetic mothers (IDM). Neonates of hypertensive women were significantly more preterm, had lower birth weight and part of multiple pregnancies. These neonates were exposed to either single or combined antihypertensive therapy. The most commonly used antihypertensive medications were labetalol 82% (n= 273/333), magnesium sulphate 21%, (n= 70/333) methyldopa 16.5% (n= 55/333) and nifedipine 14%; (n= 47/333). There was no significant difference in the mean initial blood glucose between neonates in the hypertensive versus non-hypertensive groups of mothers (1.7 vs 1.6 mmol/L). However, a sub-group comparison of neonates (with initial blood glucose <2.6 mmol/L) showed methyldopa to be marginally associated with a 2 mmol/L decrease from the mean initial blood glucose, mean 1.6 ± 0.5 mmol/L, and methyldopa (1.4 ± 0.5 mmol/L; p= .045). 

Conclusions

This retrospective study demonstrated that neonates of hypertensive mothers have significant differences in gestational age at birth, birthweight, occurrence of respiratory distress and prematurity. Hypoglycemia were more prevalent among neonates of non-hypertensive mothers. On the other hand, neonates of hypertensive mothers administered with methyldopa showed a significant decrease of initial blood glucose reading.