![]() |
|
|
Division of Pediatric Gastroenterology and Nutrition, UMDNJ-Robert Wood Johnson School of Medicine, New Brunswick, NJ and * Division of Pediatric Gastroenterology and Nutrition, The Floating Hospital for Children at New England Medical Center and Tufts University School of Medicine, Boston, MA
2To whom correspondence should be addressed.
| ABSTRACT |
|---|
|
|
|---|
KEY WORDS: intrauterine growth retardation pregnancy weight gain trimester humans
| INTRODUCTION |
|---|
|
|
|---|
Studies of maternal weight gain during pregnancy also reveal an
increased risk of IUGR in mothers with low pregnancy weight gain
(Edwards et al. 1979
,Kramer 1987
,
Naeye 1981
, Smith 1947
, Stein et al. 1995
). However, maternal weight gain and fetal growth vary
greatly throughout pregnancy. Low weight gain in early, middle and late
pregnancy are likely to affect the fetus differently. Siega-Riz et al. (1996
) reported a twofold increase in the risk of
prematurity with low maternal weight gain in the third trimester. Lantz et al. (1996
) demonstrated increased weight in twins
when higher maternal weight gain occurred both before and after 20 wk
gestation. In adolescents, low weight gain by 12 wk gestation was not
associated with a significantly increased risk of delivering a
low-birth-weight infant, but low weight gain by 20 wk gestation was
associated with a twofold increased risk (Scholl et al. 1990
).
To explore the risk of IUGR in infants by weight gain in each trimester, we analyzed data from the National Collaborative Perinatal Project (NCPP) as well as the Child Health and Development Study (CHDS). Both studies were large, prospective studies designed to investigate the relationship between pregnancy and environmental-related variables in childhood growth and development. Because of the large number of patients enrolled and comprehensive prenatal and postnatal follow-up, these cohorts are ideal for calculating the effect of maternal weight gain in each trimester to subsequent fetal outcome.
| METHODS |
|---|
|
|
|---|
The NCPP cohort consisted of all mothers and full-term infants enrolled in the NCPP, an eight-center multicenter prospective study conducted from 1959 to 1976 that followed women enrolled during pregnancy and their infants. Women were predominantly enrolled from a mixed racial, urban population. The Child Health and Development Study, conducted from 1959 to 1973, followed women and their infants in the San Francisco Bay are in the Kaiser Health system, predominantly a white suburban population. To more accurately capture gestational age, prepregnancy weight and first trimester weight gain, we only included patients enrolled within 14 wk of their last menstrual period (LMP). Pregnancy complications were elicited at the time of registration and throughout pregnancy. Gestational age was measured by dating the last menstrual period at the time of registration. Prepregnancy weight was determined by maternal recall at the time of registration.
Measures.
First trimester weight gain was calculated as the average weekly weight gain between the prepregnancy weight and the end of the first trimester (1316 wk from LMP). Second trimester weight gain was calculated as the average weekly weight gain between the end of the first trimester and the end of the second trimester (2629 wk from LMP). Third trimester weight gain was calculated as the average weekly weight gain between the end of the second trimester and delivery. Total pregnancy weight gain was calculated as the difference between the prepregnancy weight and maternal weight at delivery.
We defined low weight gain in the second and third trimester as <0.3
kg/wk, in accordance with the suggestions of The Institute of Medicine
(1990a)
. No guidelines for first trimester weight gain
were given by the Institute of Medicine; therefore, we defined low
first trimester weight gain as < -0.1 kg/wk, which corresponds to
~1 SD below the mean weight of healthy, normal women
(Abrams and Selvin 1995
). Low pregnancy weight gain was
defined as <6.8 kg (fifteenth percentile of NCPP and CHDS cohorts),
which also corresponds to the recommendations of the Institute of
Medicine (1990a)
.
All infants were initially measured by trained study staff at the time
of admission to the nursery. Birth weight was measured on calibrated
scales, and birth length was measured with standard measuring tapes.
Patients were classified as having IUGR if their birth weight at term
was <2500 g. Infants were excluded in they had a gestational age <37
wk, multiple gestation, neural tube defect, chromosomal anomaly, or
other severe congenital disease. Maternal body mass index (BMI) was
calculated using prepregnancy weight and height (kg/m2).
Maternal BMI was categorized as low (BMI <20.0 kg/m2),
normal (20.0 kg/m2
BMI < 25 kg/m2), or
high (25.0 kg/m2
BMI) according to the World Health
Organization guidelines (1988)
. Too few women with very
high BMI (BMI > 30 kg/m2) were included in the study
to calculate separate relative risks. In the NCPP study 10,696 women
met the entry criteria, and data to calculate weight gain in every
trimester were available in 5,403 (51%). In the CHDS study 9,229 women
met the entry criteria; adequate data were available in 5,353 (58%).
The remainder of patients in both the NCPP and CHDS studies were
excluded because they enrolled after 14 wk gestation or delivered
preterm infants.
Statistics.
Data were analyzed using the SPSS-X program (SPSS, Chicago, IL.).
Differences in proportions were compared with
2.
Differences in continuous variables were determined by independent
t-test. Relative risk was assessed using multivariate
logistic regression, and 95% confidence intervals were calculated from
these regressions. Combined data from both cohorts were used to
calculate the relative risk of IUGR in women with differing BMI.
Multivariate logistic regression was utilized to assess the effects of
demographic variables on the risk of low weight gain in the second or
third trimester.
| RESULTS |
|---|
|
|
|---|
Both the NCPP and CHDS cohorts differed significantly in their racial
and socioeconomic backgrounds (Table 1
). A significantly higher proportion of African-Americans
(P < 0.001), single mothers (P < 0.001), teenage mothers (P < 0.001), and smokers
(P < 0.001) were enrolled in the NCPP study,
reflecting the urban environment from which these women were
predominantly recruited. In contrast, women enrolled in the CHDS study
were more likely to have graduated from high school (P
< 0.001) and were older (P < 0.001). Infant
length (P < 0.001) and weight (P < 0.001) were also significantly lower in the NCPP cohort.
|
Risk for IUGR.
Low maternal weight gain during the first trimester had no significant
effect on the prevalence of IUGR in either cohort (Table 2
). However, in both the NCPP and the CHDS studies low weight gain
in the second trimester increased the risk of intrauterine growth
retardation significantly [NCPP: 1.52 (1.031.97); CHDS: 1.87
(1.242.82)]. Low weight gain in the third trimester also
significantly increased the risk of intrauterine growth retardation in
both cohorts [NCPP: 1.52 (1.041.91); CHDS: 1.82 (1.242.65)]. The
risk of intrauterine growth retardation was even higher after
controlling for other factors known to affect fetal weight, such as
maternal height, BMI, parity, smoking, toxemia and diabetes (Table 2)
.
The increased risk of intrauterine growth retardation with low weight
gain in the second or third trimester remained significantly elevated,
even after controlling for the rate of weight gain in the other
two trimesters (Table 2)
.
|
Because of limited numbers of patients with IUGR in the low and high
BMI categories, relative risks were calculated using data from the
combined cohorts. Low first trimester weight gain did not significantly
increase the risk of intrauterine growth retardation in women with
either low or elevated prepregnancy BMI (Table 3
). Women with normal prepregnancy BMI demonstrated a mildly
increased risk of IUGR with low first trimester weight gain, although
this risk was no longer significant after controlling for confounding
factors (Table 3)
. In contrast, women with low weight gain in the
second trimester demonstrated an approximately twofold increase in the
rate of intrauterine growth retardation across the maternal weight
spectrum (Table 3)
. A similar trend was observed with low maternal
third trimester weight gain, although this relationship was not
statistically significant in overweight women after controlling for
confounding factors (Table 3)
.
|
Approximately three-quarters (7382%) of patients with low weight
gain in the second or third trimester had normal weight gain over the
entire pregnancy (Table 4
). Maternal marital status, race, and educational status were not
consistently related to low weight gain in either the second or third
trimester in both the NCPP and CHDS study (Table 5
). Maternal age and body mass index in both cohorts significantly
affected the risk of low weight gain. In particular, teenage mothers
were approximately one half as likely to have low weight gain in either
the second or third trimester as nonteenage mothers. In contrast, women
aged 35 y or older were approximately twice as likely to have low
weight gain in the second or third trimester.
|
|
In both cohorts, the risk of obtaining erroneous gestational ages
(i.e., gestational age >43 wk) was two-to-three times more likely in
women enrolled during the second or third trimester compared to women
enrolled during the first trimester. Therefore, to obtain the most
accurate assessment of gestational age, women were only included who
enrolled in the first trimester of pregnancy. Women with complete and
incomplete first trimester data demonstrated only minor differences in
demographic characteristics and pregnancy weight gain (Table 6
). In contrast, women enrolled in the second or third trimester
were less educated, younger, and more likely to be African-American
compared to women enrolled in the first trimester. Because accurate
assessment of third trimester weight gain was also possible in women
enrolled in the second trimester of pregnancy, risk of IUGR was
calculated in these women (Table 7
). Similarly, increased risks of intrauterine growth retardation
with low third trimester weight gain were observed in both cohorts
independent of when the women enrolled in the study. This suggests that
enrollment bias had little effect on the studies main outcomes.
|
|
| DISCUSSION |
|---|
|
|
|---|
Other studies also indicated that low trimester weight gain,
particularly in the second trimester, is important for fetal growth.
Abrams and Selvin (1995)
demonstrated that low maternal
weight gain in the second trimester (<5.7 kg) was associated with
decreased birth weights ranging from 48 to 248 g, depending on the
pattern of weight gain in the other trimesters. In contrast, isolated
low first and third trimester weight gain was not associated with
significantly decreased birth weight in that study by Abrams and Selvin (1995)
. Similarly, Hickey et al. (1996)
also demonstrated that low prenatal weight gain, particularly involving
the second trimester, significantly decreased birth weight. Finally,
Lawton et al. (1988)
showed significantly lower maternal
weight gain between 28 and 32 wk gestation resulted in infants born
small for gestation compared to normal weight infants.
These results are particularly important because the majority of
patients with low weight gain in an individual trimester have normal
total pregnancy weight gain. In addition, the increased risk of IUGR
remained even after controlling for the amount of weight gain in the
other trimesters. Our results support the work by Scholl et al. (1990)
who also demonstrated a twofold increase in low
birth weight infants associated with low maternal weight gain in mid or
late pregnancy. Hediger et al. (1989)
also demonstrated
that low weight gain by 24 wk gestation increased the risk of low birth
weight infants, even if total weight gain was normal. . However, both
previous studies were limited to adolescent mothers, whereas our study
demonstrates similar results in a more comprehensive cohort.
Our data supports the Institute of Medicine (1990a)
recommendation that overweight women should gain at least 0.3 kg/wk
over both the second and third trimesters. We demonstrated that the
elevated risk of intrauterine growth retardation remained in overweight
women with low second trimester weight gain and low third trimester
weight gain, even after controlling for confounding variables. In
addition, particular attention must be given to women aged 35 y or
older because these women are almost twice as likely to have low weight
gain in either the second or third trimester. Similarly, overweight
women and women who smoke also demonstrated lower rates of second and
third trimester weight gain. Our results confirm data of Abrams et al. (1995)
who also demonstrated decreased rates of
second and third trimester weight gain associated with smoking, older
maternal age, as well as increased body mass index. Similarly, other
investigators (Ancri et al. 1997
, Muscati et al. 1988
) also demonstrated lower total pregnancy weight gain in
older women compared to younger women.
Our findings also support the hypothesis that the timing of
pregnancy-related variables greatly influences fetal growth.
Maternal weight gain and fetal growth vary greatly throughout pregnancy
(Bernstein et al. 1997
, Hytten and Leitch 1971
, Widdowson 1994
). During the first
trimester, the fetus mainly undergoes organogenesis, while growth is
minimal. First trimester insults are therefore likely to be
teratogenic, with little effect on neonatal growth. We found no
consistently increased risk of intrauterine growth retardation even
with mild maternal weight loss in the first trimester, consistent with
these assumptions. In contrast, a study by Smith et al. (1998)
demonstrates a twofold increased risk of
full-term IUGR with poor first trimester fetal growth. However, the
study by Smith et al. may be limited by sample bias. Only 3,397 of
31,269 infants with fetal ultrasounds met the strict entry criteria. In
addition, only 3% of full-term infants who had poor first
trimester growth were born with a birth weight <2500 g. Finally,
because fetal size, and hence energy demands, are relatively small in
the first trimester, first trimester fetal growth is unlikely to be
dependent on adequate maternal weight gain.
In the second trimester, fetal growth is the most rapid, and therefore,
most likely to be influenced by maternal nutrition. Fetal weight
increases by ~12-fold between 14 and 28 wk (Moore 1982
). Low maternal weight gain during the second trimester
doubled the risk of intrauterine growth retardation even though the
contribution of fetal weight to maternal weight gain during this
trimester is minimal. In the third trimester, the fetus quadruples its
fat mass (Moore 1982
). Adequate fetal nutrition during
this period also remains critical. However, fetal and placental weight
gain in the third trimester may account for up to one half of maternal
weight gain. Therefore, low maternal weight gain in the third trimester
may be an effect of intrauterine growth retardation and not a cause.
Unfortunately, efforts to manipulate fetal nutrition through maternal
dietary changes have been contradictory. Data from developing countries
suggest that nutritional supplementation in pregnancy leads to
significantly increased total pregnancy weight gain
(Mardones-Santander et al. 1981
, Tontisirin et al. 1986
) and modest increases in birth weight (30250 g) in
women at nutritional risk (Lechtig et al. 1975
,
Mardones-Santander et al. 1981
,Tontisirin et al. 1986
). However, little equivalent data exists to support the
use of routine nutritional supplementation in the USA or Europe. Rush et al. (1980)
performed a double blinded study of
nutritional supplementation during pregnancy in poor, black, urban
women who were at high risk for delivering infants with intrauterine
growth retardation. Women who received a high protein supplement had
increased number of preterm deliveries, neonatal death and growth
retardation up to 37 wk gestation, despite increased maternal weight
gain. However, in women receiving supplemental food aid through the WIC
program, there was a significant increase in head circumference at
birth, although there was no noticeable effect on birth weight or
intrauterine growth retardation (Rush et al. 1988
).
Unfortunately, maternal weight gain was not evaluated. Studies of
nutritional supplementation in Canada also revealed small, but
significant influences on average birth weight, but no significant
differences in the incidence of low birth weight infants or the amount
of maternal weight gain during pregnancy (Rush 1981
).
We chose to define intrauterine growth retardation as a term birth
weight below 2500 g. Our definition is consistent with previous
studies (reviewed by Kramer 1987
), and is largely based on the
increased morbidity and mortality in infants born below this birth
weight (McCormick 1985
). Long-term health
consequences were also described in full term-infants born
below 2500 g (Barker 1997
,Curhan et al. 1996
). Other authors have variably defined IUGR as a birth
weight less than the tenth percentile for gestational age, less than
the fifth percentile for gestational age, or <2 SD (third
percentile) for gestational age. However, gestational age based
criteria are limited by the reference standard utilized (Miller 1981
). Finally, we have limited the accidental
misclassification of preterm infants by only including patients
enrolled within the first trimester. In women enrolled in prenatal care
before 1618 wk gestation, Kramer et al. (1988)
have
demonstrated gestational dating by LMP is extremely accurate in term
infants.
Unfortunately, this study utilizes relatively old data. During the
1960s to 1970s recommendations for the amount of weight a pregnant
women should gain were substantially lower than current recommendations
(Institute of Medicine 1990b
). In fact, the
12th edition of Williams Obstetrics
(1961) recommended limiting pregnancy weight gain to 11.4 kg
(Eastman and Hellman 1961
). As a result, mean weight
gain in the two cohorts averaged 24 kg lower than currently observed
averages. Nevertheless, in the 1990s, ~40% of black women and 25%
of white women continue to gain <9 kg throughout their pregnancy
(Caulfield et al. 1996
), which is less than the average
weight gain in both cohorts in the current study. In addition, the
definition of low trimester gain utilized in this study (0.3 kg/wk for
second and third trimester) is consistent with rates of weight gain
occurring in ~1525% of contemporary pregnancies (Abrams and Selvin 1995
, Carmichael et al. 1997
).
In conclusion, increased awareness of maternal weight gain in mid and
late pregnancy is critical to identifying infants at risk for IUGR.
Fetal growth may be impaired by relatively short periods of poor
maternal weight gain, even if subsequent weight gain is adequate.
However, nutritional supplementation of all mothers with poor
gestational weight gain is not currently indicated because previous
experience has been contradictory. According to The Institute of
Medicine (1990a)
: "When abnormal weight gain appears
to be real, rather than a result of an error in measurement or
recording, try to determine the cause and then develop and implement
corrective actions jointly with the women
If it appears that a lower
than recommended weight gain is the result of an inadequate food supply
or inappropriate self-restriction, corrective measures should be
taken promptly."
| FOOTNOTES |
|---|
3 Abbreviations used: BMI, body mass index; CHDS,
Child Health and Development Study; IUGR, Intrauterine growth
retardation; LMP, last menstrual period; NCPP, National Collaborative
Perinatal Project. ![]()
Manuscript received September 30, 1998. Initial review completed December 30, 1998. Revision accepted January 29, 1999.
| REFERENCES |
|---|
|
|
|---|
1. Abrams B., Selvin S. Maternal weight gain pattern and birth weight. Obstet. Gynecol. 1995;86:163-169[Abstract]
2. Abrams B., Carmichael S., Selvin S. Factors associated with the pattern of maternal weight gain during pregnancy. Obstet. Gynecol. 1995;86:170-176[Abstract]
3.
Ancri G., Morse E. H., Clarke R. P. Comparison of nutritional status of pregnant adolescents with adult pregnant women. III. Maternal protein and calorie intake and weight gain in relation to size of infant at birth. Am. J. Clin. Nutr. 1977;30:568-572
4. Babson S. G., Kangas J., Young N., Bramhall J. L. Growth and development of twins of dissimilar size at birth. N. Engl. J. Med. 1973;289:937-940
5.
Barker D.J.P. Fetal nutrition and cardiovascular disease in later life. Brit. Med. Bull. 1997;53:96-108
6. Bernstein I. M., Goran M. I., Amini S. B., Catalona P. M. Differential growth of fetal tissues during the second half of pregnancy. Am. J. Obstet. Gynecol. 1997;176:28-32[Medline]
7.
Carmichael S., Abrams B., Selvin S. The pattern of maternal weight gain in women with good pregnancy outcomes. Am. J. Public Health 1997;87:1984-1988
8. Caulfield L. E., Witter F. R., Stoltzfus R. J. Determinants of gestational weight gain outside the recommended ranges among black and white women. Obstet. Gynecol. 1996;87:760-766[Abstract]
9.
Curhan G. C., Chertow G. M., Willett W. C., Spiegelman D., Coditz G. A., Manson J. E., Speizer F. E., Stampfer M. J. Birth weight and adult hypertension and obesity in women. Circulation 1996;94:1310-1315
10. Eastman N. J., Hellman L. M. Williams Obstetrics 12th ed. 1961 Appleton-Century-Crofts New York, NY.
11. Edwards L. E., Alton L. R., Barrada M. I., Hakanson E. Y. Pregnancy in the underweight woman: Course, outcome and growth patterns of the infant. Am. J. Obstet. Gynecol. 1979;135:297-302[Medline]
12. Frederick J., Adelstein P. Factors associated with low birth weight infants delivered at term. Br. J. Obstet. Gynecol. 1978;85:1-7
13. Henrichsen L., Skinhoj K., Anderson G. E. Delayed growth and reduced intelligence in 917 year old intrauterine growth retarded children compared with their monozygous co-twins. Acta Paediatr. Scand. 1986;75:31-35[Medline]
14.
Hediger M. L., Scholl T. O., Belsky D. H., Ances I. G., Salmon R. W. Patterns of weight gain in adolescent pregnancy: Effects on birth weight and preterm delivery. Obstet. Gynecol. 1989;74:6-12
15. Hickey C. A., Cliver S. P., McNeal S. F, Hoffman H. J., Godenberg R. L. Prenatal weight gain patterns and birth weight among nonobese black and white women. Obstet. Gynecol. 1996;88:490-496[Abstract]
16. Hytten F. E., Leitch I. The Physiology of Human Pregnancy 2nd ed. 1971 Blackwell Scientific Publications Oxford, UK.
17. Institute of Medicine (United States) Subcommittee on nutritional status and weight gain during pregnancy.(1990) Nutrition During Pregnancy, pp. 123, 96120. National Academy Press, Washington DC.
18. Institute of Medicine (United States) Subcommittee on Nutritional Status and Weight Gain During Pregnancy.(1990)Historical trends in clinical practice, maternal nutritional status, and the course of and outcome of pregnancy. In: Nutrition During Pregnancy, pp. 3762. National Academy Press, Washington DC.
19. Koops B. L., Morgan L. J., Battaglia F. C. Neonatal mortality risk in relation to birth weight and gestational age: Update. J. Pediatr. 1982;101:969-977[Medline]
20. Kramer M. S. Determinants of low birth weight: Methodological assessment and meta-analysis. Bull. World Health Organ. 1987;65:663-737[Medline]
21. Kramer M. S., McLean F. H., Boyd M. E., Usher R. H. The validity of gestational age estimation by menstrual dating in term, preterm, and postterm gestations. JAMA 1988;260:3306-3308[Abstract]
22. Kramer M. S., Olivier M., McLean F. H., Willis D. M., Usher R. H. Impact of intrauterine growth retardation and body proportionality on fetal and neonatal outcome. Pediatrics 1990;85:707-713
23. Lantz M. E., Chez R. A., Rodriguez A., Porter K. B. Maternal weight gain patterns and birth weight outcome in twin gestation. Obstet. Gynecol. 1996;87:551-556[Abstract]
24. Lawton F. G., Mason G. C., Kelly K. A., Ramsay I. N., Morewood G. A. Poor maternal weight gain between 28 and 32 wk gestation may predict small-for-gestational-age infants. Br. J. Obstet. Gynecol. 1988;95:884-887[Medline]
25.
Lechtig A., Habicht J. P., Delgado H., Klein R. E., Yarbrough C., Martorell R. Effect of food supplementation during pregnancy on birthweight. Pediatrics 1975;56:508-520
26. Low J. A., Galbraith R. S., Muir D., Killen H. L., Palen E. A., Gale R. Intrauterine growth retardation: a study of long-term morbidity. Am. J. Obstet. Gynecol. 1982;142:670-677[Medline]
27.
Mardones-Santander F., Rosso P., Steckel E., Ahumada S., Llaguno S., Pizarro J., Salinas I., Vial I., Walter T. Effect of a milk-based food supplement on maternal nutritional status and fetal growth in underweight Chilean women. Am. J. Clin. Nutr. 1981;47:413-419
28. McCormick M. C. The contribution of low birth weight to infant mortality and childhood morbidity. N. Engl. J. Med. 1985;312:82-90[Abstract]
29. Miller H. C. Intrauterine growth retardation: An unmet challenge. Am. J. Dis. Child. 1981;135:944-948[Abstract]
30. Moore K. L. The fetal period. The Developing Human 3rd ed. 1982:93-110 WB Saunders Philadelphia, PA.
31. Muscati S. K., Mackey M. A., Newsom B. The influence of smoking and stress on prenatal weight gain and infant birth weight of teenage mothers. J. Nutr. Educ. 1988;20:299-302
32.
Naeye R. L. Nutritional/Nonnutritional interactions that affect the outcome of pregnancy. Am. J. Clin. Nutr. 1981;34:727-731
33. Paz I., Seidman D. S., Danon Y. L., Laor A., Stevenson D. K., Gale R. Are children born small for gestational age at increased risk for short stature?. Am. J. Dis. Child. 1993;147:337-339[Abstract]
34. Rush D. Nutritional services during pregnancy and birthweight: A retrospective matched pair analysis. Can. Med. Assoc. J. 1981;125:567-576[Abstract]
35.
Rush D., Sloan N. L., Leighton J., Alvir H. M., Horvitz D. G., Seaver W. B., Garbowski G. C., Johnson S. S., Kulka R. A., Holt M. The National WIC Evaluation: Evaluation of the special supplemental food program for women, infants, and children. V. Longitudinal study of pregnant women. Am. J. Clin. Nutr. 1988;48:439-483
36.
Rush D., Stein Z., Susser M. A randomized controlled trial of prenatal nutritional supplementation in New York City. Pediatrics 1980;65:683-697
37.
Scholl T. O., Hediger M. L., Ances I. G., Belsky D. H., Salmon R. W. Weight gain during pregnancy in adolescence: Predictive ability of early weight gain. Obstet. Gynecol. 1990;75:948-953
38. Siega-Riz A. M., Adair L. S., Hobel C. J. Maternal underweight status and inadequate rate of weight gain during the third trimester of pregnancy increases the risk of preterm delivery. J. Nutr. 1996;126:146-153
39. Smith C. A. Effects of maternal undernutrition upon the newborn infant in Holland (19441945). J. Pediatr. 1947;30:229-243
40.
Smith G.C.S., Smith M.F.S., McNay M. B., Flemming J.E.E. First-trimester growth and the risk of low birth weight. N. Engl. J. Med. 1998;339:1817-1822
41. Stein A. D., Ravelli A.C.J., Lumey L. H. Famine, third-trimester pregnancy weight gain, and intrauterine growth: The Dutch Famine Birth Cohort. Hum. Biol. 1995;67:135-150[Medline]
42. Strauss R. S., Dietz W. H. Growth and development of full-term children born small-for gestational age. J. Pediatr. 1998;133:67-72[Medline]
43.
Tontisirin K., Booranasubkajorn U., Hongsumarn A., Thewtong T. Formulation and evaluation of supplementary foods for Thai pregnant women. Am. J. Clin. Nutr. 1986;43:931-939
44.
Westwood M., Kramer M. S., Munz D., Lovett J. M., Watters G. V. Growth and development of full-term nonasphyxiated small-for-gestational-age newborns: Follow-up through adolescence. Pediatrics 1983;71:376-382
45. Widdowson E. M. Nutrition. Davis J. A. Robson J. S. eds. Scientific Foundations of Paediatrics 1974:44-55 WB Saunders Philadelphia, PA.
46. World Health Organization.(1988)Measuring obesity: Classification and description of anthropometric data. Report on a WHO consultation on the epidemiology of obesity. Copenhagen, WHO Regional Office for Europe, Nutrition Unit.
This article has been cited by other articles:
![]() |
K. P Kleinman, E. Oken, J. S Radesky, J. W Rich-Edwards, K. E Peterson, and M. W Gillman How should gestational weight gain be assessed? A comparison of existing methods and a novel method, area under the weight gain curve Int. J. Epidemiol., December 1, 2007; 36(6): 1275 - 1282. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Villamor, M. L. Dreyfuss, A. Baylin, G. Msamanga, and W. W. Fawzi Weight Loss During Pregnancy Is Associated with Adverse Pregnancy Outcomes among HIV-1 Infected Women J. Nutr., June 1, 2004; 134(6): 1424 - 1431. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Villamor, G. Msamanga, D. Spiegelman, G. Antelman, K. E Peterson, D. J Hunter, and W. W Fawzi Effect of multivitamin and vitamin A supplements on weight gain during pregnancy among HIV-1-infected women Am. J. Clinical Nutrition, November 1, 2002; 76(5): 1082 - 1090. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E Brown, M. A Murtaugh, D. R Jacobs Jr, and H. C Margellos Variation in newborn size according to pregnancy weight change by trimester Am. J. Clinical Nutrition, July 1, 2002; 76(1): 205 - 209. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. H. Pietilainen, J. Kaprio, M. Rasanen, T. Winter, A. Rissanen, and R. J. Rose Tracking of Body Size from Birth to Late Adolescence: Contributions of Birth Length, Birth Weight, Duration of Gestation, Parents' Body Size, and Twinship Am. J. Epidemiol., July 1, 2001; 154(1): 21 - 29. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||