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doi:10.1111/jog.12293
J. Obstet. Gynaecol. Res. Vol. 40, No. 4: 995–1001, April 2014
Relation between gestational weight gain and pregnancy outcomes Prasert Sunsaneevithayakul, Vitaya Titapant, Pornpimol Ruangvutilert, Anuwat Sutantawibul, Chayawat Phatihattakorn, Tuangsit Wataganara and Pattarawalai Talungchit Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand
Abstract Aim: The aim of this study was to evaluate the effects of gestational weight gain on pregnancy outcomes in pregnant Thai women with different pre-pregnancy body mass indexes (BMI). Materials and Methods: A retrospective study was carried out by reviewing 5200 medical records of pregnant women who delivered at the Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital during 1 September 2011–1 August 2012. Inclusion criteria were singleton pregnancy with available prepregnant weight and maternal height. Pre-pregnancy BMI were categorized according to World Health Organization criteria. Pregnancy outcomes of interest were appropriate-for-gestational-age infants. The optimal gestational weight gain for each BMI group was proposed to achieve a high proportion of appropriatefor-gestational age infants. Results: Patients were divided into four groups according to their pre-pregnancy BMI: underweight (21.3%), normal weight (64.1%), overweight (11.5%), and obese (3.1%). Optimal gestational weight gain ranges for each group were 10–18, 8–16, 6–14 and 4–8 kg, respectively. Our proposed criteria seem to be realistic, with 60% of pregnant Thai women able to adhere to the recommendation, compared to 40.5% adherence to the 2009 Institute of Medicine recommendation. There were no significant complications when following either of the recommendations. Adverse pregnancy outcomes, including large for gestational age, cesarean section, and severe pre-eclampsia, were significantly decreased in women who complied with our recommendation. Conclusion: To achieve a high proportion of appropriate-for-gestational-age infants, Thai pregnant women could follow our gestational weight gain recommendation. Key words: appropriate-for-gestational-age infant, gestational weight gain, macrosomia, pre-pregnancy body mass index, pregnancy outcomes.
Introduction Maternal and neonatal complications have been linked to pre-pregnancy body mass index (BMI) and gestational weight gain.1–5 Controlling of BMI and weight gain during pregnancy is desirable in order to optimize the perinatal outcomes. It is not always possible for all
individuals to be at an ideal BMI at the time of conception. Weight gain during pregnancy, on the other hand, is more manageable by dietary counseling and lifestyle modification.6,7 If the mother cannot achieve an optimal weight gain, there will be an increased chance of a small-for-gestational-age (SGA) baby and preterm delivery.8,9 If the weight gain is too much, the mother
Received: June 28 2013. Accepted: September 9 2013. Reprint request to: Dr Pattarawalai Talungchit, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, 2 Prannok Road, Bangkoknoi, Bangkok, Thailand 10800. Email: [email protected]
© 2014 The Authors Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology
995
P. Sunsaneevithayakul et al.
will have an increased risk of a large-for-gestationalage (LGA)/ macrosomia baby, cesarean section, gestational diabetes mellitus and pregnancy-induced hypertension.8–10 The idea of controlling weight gain during pregnancy was introduced by the Institute of Medicine (IOM) in 1990.11 Recently (2009), the revised IOM guidelines have shifted the effort toward the normalization of BMI prior to pregnancy.12 These changes have an impact on the definition of overweight and obesity, and result in an alteration in preconceptional counseling.13 In short, a BMI of 90th percentile. An SGA infant was defined as an infant having a standardized birthweight < 10th percentile. Statistical analysis Patient’s characteristics and their pregnancy outcomes are presented as percentage, mean with standard deviation (SD) or median with interquartile range (IQR). Patients were divided into four groups according to their pre-pregnancy BMI. Gestational weight gains of each group are reported and compared using median with IQR and Kruskal–Wallis test, respectively. The optimal gestational weight gain for each group was proposed to achieve a high proportion of appropriatefor-gestational-age (AGA) fetuses. The comparison of patients’ characteristics and pregnancy outcomes were analyzed using the Wilcoxon rank–sum test for continuous variables and Pearson’s χ2-test for categorical variables.
Results From a medical record review, 5200 parturients who fit the inclusion criteria were enrolled. Demographic data of the recruited subjects are shown in Table 1. The mean gestational age at delivery was 38 ± 1.6 gestational weeks with 91.7 of the subjects delivered at term (≥37 menstrual weeks). Cesarean section rate was 40.6% in our population. Significant neonatal morbidities included 0.3% admission rate to NICU and 0.1% stillbirth. Most of the newborn babies (91.5%) weighed 2500–4000 g, and 6.6% and 1.8% of our newborn babies weighed over 4000 g, and below 2500 g, respectively, as shown in Table 1. The mean gestational weight gain in our population was 14.4 kg (14.42 ± 4.98). Approximately 21.3%, 64.1%, 11.5%, and 3.1% of our recruited parturients were categorized as having underweight, normal, overweight, and obese pre-pregnancy weight, as shown in Table 2. The median gestational weight gains categorized according to the pre-pregnancy BMI groups are
© 2014 The Authors Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology
Proper gestational weight gain
illustrated in Table 2. Counter-intuitively, parturients whose pre-pregnancy weight belonged to the obese group had the lowest median gestational weight gain of 11 kg. The distribution of SGA, AGA and LGA infants according to the four pre-pregnancy BMI Table 1 Patients’ characteristics and pregnancy outcomes (n = 5200) n (%)
Characteristics Maternal age (years) (mean ± SD) Nullipara Multipara Pre-pregnancy weight (kg) (mean ± SD) Height (cm) (mean ± SD) Body mass index (kg/m2) (mean ± SD) Weight gain during pregnancy (kg) (mean ± SD) Pregnancy outcomes Gestational age at delivery (weeks) (mean ± SD) 24–33 34–36 ≥37 Route of delivery Normal labor Operative delivery Cesarean section Maternal complications Gestational diabetes Severe pre-eclampsia Eclampsia Neonatal outcomes Birthweight (kg) (mean ± SD) Small for gestational age Appropriate for gestational age Large for gestational age Neonatal intensive care unit admission Intrauterine growth restriction Stillbirth
28.47 ± 6.2 2811 (54.1) 2389 (45.9) 53.62 ± 9.99 158 ± 5.82 21.42 ± 3.72 14.42 ± 4.98 38 ± 1.6 60 (1.2) 371 (7.1) 4769 (91.7) 2991 (57.5) 97 (1.9) 2112 (40.6) 223 (4.3) 137 (2.6) 3 (0.1) 3068.4 ± 426.98 95 (1.8) 4760 (91.6) 345 (6.6) 15 (0.3) 23 (0.4) 6 (0.1)
groups is also shown in Table 2. The data suggested an incremental trend of LGA babies and lower trends of SGA babies in the population with high pre-pregnancy BMI. An official recommendation for an appropriate weight gain during pregnancy is much needed to increase the proportion of AGA infants. Based on our data, the optimal gestational weight gain for each prepregnancy BMI category is calculated as follows: 10–18 kg for the underweight group, 8–16 kg for the normal weight group, 6–14 kg for the overweight group and 4–8 kg for the obese group, as shown in Table 3. After fitting this proposed local model into our study population, the proportion of parturients whose weight gain followed this recommendation are as follows: 24.7% (n = 770) were in the underweight group; 62.9% (n = 1963) were in the normal weight group; 11.3% (n = 353) were in the overweight group; and 1.1% (n = 36) were in the obese group. This proportion was not significantly different when 2009 IOM criteria were used, as shown in Table 4. One small difference between the 2009 IOM criteria and our proposed criteria is the recommended gestational weight gain (14 kg in the 2009 IOM group, and 13 kg in our study group). Our proposed criteria seem to be more realistic, with 60% (n = 3122) of parturients able to adhere to the recommendation, compared to 40.5% (n = 2107) adherence to the 2009 IOM. Adverse pregnancy outcomes, including LGA infants, cesarean section rate, and severe pre-eclampsia, were significantly decreased in women who complied with our recommendation, as shown in Table 5.
Discussion Proper weight gain is one of the cornerstones to optimizing pregnancy outcomes. Excessive weight gain as a result of excess calorie intake can lead to an
Table 2 Median gestational weight gain and distribution of birthweight for gestational age based on pre-pregnancy BMI (n = 5200) Characteristics
doi:10.1111/jog.12293
J. Obstet. Gynaecol. Res. Vol. 40, No. 4: 995–1001, April 2014
Relation between gestational weight gain and pregnancy outcomes Prasert Sunsaneevithayakul, Vitaya Titapant, Pornpimol Ruangvutilert, Anuwat Sutantawibul, Chayawat Phatihattakorn, Tuangsit Wataganara and Pattarawalai Talungchit Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand
Abstract Aim: The aim of this study was to evaluate the effects of gestational weight gain on pregnancy outcomes in pregnant Thai women with different pre-pregnancy body mass indexes (BMI). Materials and Methods: A retrospective study was carried out by reviewing 5200 medical records of pregnant women who delivered at the Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital during 1 September 2011–1 August 2012. Inclusion criteria were singleton pregnancy with available prepregnant weight and maternal height. Pre-pregnancy BMI were categorized according to World Health Organization criteria. Pregnancy outcomes of interest were appropriate-for-gestational-age infants. The optimal gestational weight gain for each BMI group was proposed to achieve a high proportion of appropriatefor-gestational age infants. Results: Patients were divided into four groups according to their pre-pregnancy BMI: underweight (21.3%), normal weight (64.1%), overweight (11.5%), and obese (3.1%). Optimal gestational weight gain ranges for each group were 10–18, 8–16, 6–14 and 4–8 kg, respectively. Our proposed criteria seem to be realistic, with 60% of pregnant Thai women able to adhere to the recommendation, compared to 40.5% adherence to the 2009 Institute of Medicine recommendation. There were no significant complications when following either of the recommendations. Adverse pregnancy outcomes, including large for gestational age, cesarean section, and severe pre-eclampsia, were significantly decreased in women who complied with our recommendation. Conclusion: To achieve a high proportion of appropriate-for-gestational-age infants, Thai pregnant women could follow our gestational weight gain recommendation. Key words: appropriate-for-gestational-age infant, gestational weight gain, macrosomia, pre-pregnancy body mass index, pregnancy outcomes.
Introduction Maternal and neonatal complications have been linked to pre-pregnancy body mass index (BMI) and gestational weight gain.1–5 Controlling of BMI and weight gain during pregnancy is desirable in order to optimize the perinatal outcomes. It is not always possible for all
individuals to be at an ideal BMI at the time of conception. Weight gain during pregnancy, on the other hand, is more manageable by dietary counseling and lifestyle modification.6,7 If the mother cannot achieve an optimal weight gain, there will be an increased chance of a small-for-gestational-age (SGA) baby and preterm delivery.8,9 If the weight gain is too much, the mother
Received: June 28 2013. Accepted: September 9 2013. Reprint request to: Dr Pattarawalai Talungchit, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, 2 Prannok Road, Bangkoknoi, Bangkok, Thailand 10800. Email: [email protected]
© 2014 The Authors Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology
995
P. Sunsaneevithayakul et al.
will have an increased risk of a large-for-gestationalage (LGA)/ macrosomia baby, cesarean section, gestational diabetes mellitus and pregnancy-induced hypertension.8–10 The idea of controlling weight gain during pregnancy was introduced by the Institute of Medicine (IOM) in 1990.11 Recently (2009), the revised IOM guidelines have shifted the effort toward the normalization of BMI prior to pregnancy.12 These changes have an impact on the definition of overweight and obesity, and result in an alteration in preconceptional counseling.13 In short, a BMI of 90th percentile. An SGA infant was defined as an infant having a standardized birthweight < 10th percentile. Statistical analysis Patient’s characteristics and their pregnancy outcomes are presented as percentage, mean with standard deviation (SD) or median with interquartile range (IQR). Patients were divided into four groups according to their pre-pregnancy BMI. Gestational weight gains of each group are reported and compared using median with IQR and Kruskal–Wallis test, respectively. The optimal gestational weight gain for each group was proposed to achieve a high proportion of appropriatefor-gestational-age (AGA) fetuses. The comparison of patients’ characteristics and pregnancy outcomes were analyzed using the Wilcoxon rank–sum test for continuous variables and Pearson’s χ2-test for categorical variables.
Results From a medical record review, 5200 parturients who fit the inclusion criteria were enrolled. Demographic data of the recruited subjects are shown in Table 1. The mean gestational age at delivery was 38 ± 1.6 gestational weeks with 91.7 of the subjects delivered at term (≥37 menstrual weeks). Cesarean section rate was 40.6% in our population. Significant neonatal morbidities included 0.3% admission rate to NICU and 0.1% stillbirth. Most of the newborn babies (91.5%) weighed 2500–4000 g, and 6.6% and 1.8% of our newborn babies weighed over 4000 g, and below 2500 g, respectively, as shown in Table 1. The mean gestational weight gain in our population was 14.4 kg (14.42 ± 4.98). Approximately 21.3%, 64.1%, 11.5%, and 3.1% of our recruited parturients were categorized as having underweight, normal, overweight, and obese pre-pregnancy weight, as shown in Table 2. The median gestational weight gains categorized according to the pre-pregnancy BMI groups are
© 2014 The Authors Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology
Proper gestational weight gain
illustrated in Table 2. Counter-intuitively, parturients whose pre-pregnancy weight belonged to the obese group had the lowest median gestational weight gain of 11 kg. The distribution of SGA, AGA and LGA infants according to the four pre-pregnancy BMI Table 1 Patients’ characteristics and pregnancy outcomes (n = 5200) n (%)
Characteristics Maternal age (years) (mean ± SD) Nullipara Multipara Pre-pregnancy weight (kg) (mean ± SD) Height (cm) (mean ± SD) Body mass index (kg/m2) (mean ± SD) Weight gain during pregnancy (kg) (mean ± SD) Pregnancy outcomes Gestational age at delivery (weeks) (mean ± SD) 24–33 34–36 ≥37 Route of delivery Normal labor Operative delivery Cesarean section Maternal complications Gestational diabetes Severe pre-eclampsia Eclampsia Neonatal outcomes Birthweight (kg) (mean ± SD) Small for gestational age Appropriate for gestational age Large for gestational age Neonatal intensive care unit admission Intrauterine growth restriction Stillbirth
28.47 ± 6.2 2811 (54.1) 2389 (45.9) 53.62 ± 9.99 158 ± 5.82 21.42 ± 3.72 14.42 ± 4.98 38 ± 1.6 60 (1.2) 371 (7.1) 4769 (91.7) 2991 (57.5) 97 (1.9) 2112 (40.6) 223 (4.3) 137 (2.6) 3 (0.1) 3068.4 ± 426.98 95 (1.8) 4760 (91.6) 345 (6.6) 15 (0.3) 23 (0.4) 6 (0.1)
groups is also shown in Table 2. The data suggested an incremental trend of LGA babies and lower trends of SGA babies in the population with high pre-pregnancy BMI. An official recommendation for an appropriate weight gain during pregnancy is much needed to increase the proportion of AGA infants. Based on our data, the optimal gestational weight gain for each prepregnancy BMI category is calculated as follows: 10–18 kg for the underweight group, 8–16 kg for the normal weight group, 6–14 kg for the overweight group and 4–8 kg for the obese group, as shown in Table 3. After fitting this proposed local model into our study population, the proportion of parturients whose weight gain followed this recommendation are as follows: 24.7% (n = 770) were in the underweight group; 62.9% (n = 1963) were in the normal weight group; 11.3% (n = 353) were in the overweight group; and 1.1% (n = 36) were in the obese group. This proportion was not significantly different when 2009 IOM criteria were used, as shown in Table 4. One small difference between the 2009 IOM criteria and our proposed criteria is the recommended gestational weight gain (14 kg in the 2009 IOM group, and 13 kg in our study group). Our proposed criteria seem to be more realistic, with 60% (n = 3122) of parturients able to adhere to the recommendation, compared to 40.5% (n = 2107) adherence to the 2009 IOM. Adverse pregnancy outcomes, including LGA infants, cesarean section rate, and severe pre-eclampsia, were significantly decreased in women who complied with our recommendation, as shown in Table 5.
Discussion Proper weight gain is one of the cornerstones to optimizing pregnancy outcomes. Excessive weight gain as a result of excess calorie intake can lead to an
Table 2 Median gestational weight gain and distribution of birthweight for gestational age based on pre-pregnancy BMI (n = 5200) Characteristics
