Maternal Size and the Development of Pregnancy-induced Hypertension

Abstract

Maternal Size and the Development of Pregnancy-induced Hypertension

Wisit                Chaveepojnkamjorn   DVM, MPH

Natchaporn    Pichainarong                DrPH

Department of Epidemiology, Faculty of Public Health, Mahidol University

Objective: To study the relation between maternal size and the development of pregnancy-induced hypertension (PIH)

Study design: Prospective cohort study.

Setting: Four Maternal and Child Hospital (Ratchaburi, Khon Kaen, Yala and NaKhon Sawan ) and Rajvithi Hospital.

Subjects: Two thousand and three hundred pregnant women who attended prenatal services and delivered at 4 Maternal and Child Hospital and Rajvithi Hospital during 9 months between 1^st July 1995 and  31^st March 1996.

Methods: Data were collected by questionnaires, record forms and medical instruments which comprised 3 parts: part 1 general characteristics including demography and socio-economy, part 2 specific information including gestational age, history of illness during pregnancy, and part 3 measurement data including body weight, height, blood pressure etc, The obtained data were analyzed by statistical program.

Main outcome measures: Mean and standard deviation of body mass index (BMA) before pregnancy and delivery, weight gain during gestational age and infant birth weight.

Results: Group of BMI < 23 kg/m² before pregnancy had the proportion of PIH higher than those of BMI < 21 kg/m² and 21-23 kg/m² (p < 0.001, p = 0.001 respectively).  Group of weight gain during pregnancy > 16 kg had the proportion of PIH higher than those of < 12 kg and 12-16 kg (p < 0.001 in both groups).  Group of BMI at delivery 25 kg/m² had the proportion of PIH higher than group of BMI < 25 kg/m² (p < 0.001), and infant birth weight group of lesser than 2,800 g had the proportion of PIH higher than those of 3,000 g and 2,801-2,999 g (p < 0.001 in both groups). In the aspect of PIH status, the results revealed that the average figures of BMI before pregnancy and during the following delivery, and weight gain during gestational age in the PIH group were higher than the non-PIH group (P < 0.001).  On the reverse association, mean of birth weight in the PIH group was lesser than the latter one.

Conclusion: Pregnant women of BMI > 23 kg/m² before pregnancy and weight gain > 16 kg had chance more likely to develop PIH than other groups. Therefore, controlling of body weight before and during pregnancy was the essential measure to decrease the occurrence of PIH.

Key words: maternal size, pregnancy-induced hypertension, birth weight

Vajira Med J 2003 ; 47 : 47 - 55