Patterns of maternal weight gain in pregnancy

Human Placental LRP5 and Sclerostin are Increased in Gestational Diabetes Mellitus Pregnancies

INTRODUCTION

The low-density lipoprotein receptor-related protein 5 (LRP5) and its inhibitor sclerostin, are key components of bone metabolism and potential contributors to type 2 diabetes mellitus susceptibility. This study aims at evaluating the expression of placental LRP5 and sclerostin in pregnancies with gestational diabetes mellitus (GDM) and investigate possible associations with umbilical sclerostin concentrations and clinical outcomes in mothers and their neonates.

METHODS

Twenty-six GDM-mothers and 34 non-GDM mothers of Caucasian origin and their neonates admitted in a gynecology and obstetrics department of a university hospital were included in this study. Demographic data and maternal fasting glucose concentrations (24-28 weeks of gestation) were retrieved from the patients' medical records. Placental LRP5 was determined by immunohistochemistry (IHC) and Western blotting analysis; placental sclerostin was determined by IHC. Umbilical serum sclerostin concentrations were measured by ELISA.

RESULTS

Placental sclerostin IHC intensity values were positively correlated with LRP5 values as detected either by IHC (r = 0.529; P < .001) or Western blotting (r = 0.398; P = .008), with pregestational maternal body mass index values (r = 0.299; P = .043) and with maternal fasting glucose concentrations (r = 0.475; P = .009). Placental sclerostin and LRP5 were significantly greater in GDM compared with non-GDM placentas (histo-score: 65.08 ± 17.09 vs 11.45 ± 2.33, P < .001; 145.53 ± 43.74 vs 202.88 ± 58.65, P < .001; respectively).

DISCUSSION

Sclerostin and LRP5 were detected in human placentas. The overexpression of placental sclerostin and LRP5 values in GDM compared with non-GDM pregnancies, as well as the positive association of placental sclerostin values with pregestational maternal body mass index and maternal fasting glucose concentrations may indicate the development of an adaptive mechanism in face of maternal hyperglycemia.

Gestational weight gain charts for different body mass index groups for women in Europe, North America, and Oceania

BACKGROUND

Gestational weight gain differs according to pre-pregnancy body mass index and is related to the risks of adverse maternal and child health outcomes. Gestational weight gain charts for women in different pre-pregnancy body mass index groups enable identification of women and offspring at risk for adverse health outcomes. We aimed to construct gestational weight gain reference charts for underweight, normal weight, overweight, and grades 1, 2 and 3 obese women and to compare these charts with those obtained in women with uncomplicated term pregnancies.

METHODS

We used individual participant data from 218,216 pregnant women participating in 33 cohorts from Europe, North America, and Oceania. Of these women, 9065 (4.2%), 148,697 (68.1%), 42,678 (19.6%), 13,084 (6.0%), 3597 (1.6%), and 1095 (0.5%) were underweight, normal weight, overweight, and grades 1, 2, and 3 obese women, respectively. A total of 138, 517 women from 26 cohorts had pregnancies with no hypertensive or diabetic disorders and with term deliveries of appropriate for gestational age at birth infants. Gestational weight gain charts for underweight, normal weight, overweight, and grade 1, 2, and 3 obese women were derived by the Box-Cox t method using the generalized additive model for location, scale, and shape.

RESULTS

We observed that gestational weight gain strongly differed per maternal pre-pregnancy body mass index group. The median (interquartile range) gestational weight gain at 40 weeks was 14.2 kg (11.4-17.4) for underweight women, 14.5 kg (11.5-17.7) for normal weight women, 13.9 kg (10.1-17.9) for overweight women, and 11.2 kg (7.0-15.7), 8.7 kg (4.3-13.4) and 6.3 kg (1.9-11.1) for grades 1, 2, and 3 obese women, respectively. The rate of weight gain was lower in the first half than in the second half of pregnancy. No differences in the patterns of weight gain were observed between cohorts or countries. Similar weight gain patterns were observed in mothers without pregnancy complications.

CONCLUSIONS

Gestational weight gain patterns are strongly related to pre-pregnancy body mass index. The derived charts can be used to assess gestational weight gain in etiological research and as a monitoring tool for weight gain during pregnancy in clinical practice.

Weighing as a stand-alone intervention does not reduce excessive gestational weight gain compared to routine antenatal care: a systematic review and meta-analysis of randomised controlled trials

Background

Excessive gestational weight gain is associated with short and long-term adverse maternal and infant health outcomes, independent of pre-pregnancy body mass index. Weighing pregnant women as a stand-alone intervention during antenatal visits is suggested to reduce pregnancy weight gain. In the absence of effective interventions to reduce excessive gestational gain within the real world setting, this study aims to test if routine weighing as a stand-alone intervention can reduce total pregnancy weight gain and, in particular, excessive gestational weight gain.

Methods

A systematic review and meta–analysis of randomised controlled trials (RCTs) was conducted between November 2014 and January 2016, and reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Seven databases were searched. A priori eligibility criteria were applied to published literature by at least two independent reviewers. Studies considered methodologically rigorous, as per the Academy of Nutrition and Dietetics Quality Criteria Checklist for Primary Research, were included. Meta-analysis was conducted using fixed-effects models.

Results

A total of 5223 (non-duplicated) records were screened, resulting in two RCTs that were pooled for meta-analysis (n = 1068 randomised participants; n = 538 intervention, n = 534 control). No difference in total weight gain per week was observed between intervention and control groups (weighted mean difference (WMD) -0.00 kg/week, 95% confidence interval (CI) -0.03 to 0.02). There was also no reduction in excessive gestational weight gain between intervention and control, according to pre-pregnancy body mass index (BMI). However, total weight gain was lower in underweight women (n = 23, BMI <18.5 kg/m²) in the intervention compared to control group (−0.12 kg/week, 95% CI −0.23 to −0.01). No significant differences were observed for other pregnancy, birth and infant outcomes.

Conclusion

Weighing as a stand-alone intervention is not worse nor better at reducing excessive gestational weight gain than routine antenatal care.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-1207-2) contains supplementary material, which is available to authorized users.

Higher maternal leptin levels at second trimester are associated with subsequent greater gestational weight gain in late pregnancy

BACKGROUND

Excessive gestational weight gain (GWG) is associated with adverse pregnancy outcomes. In non-pregnant populations, low leptin levels stimulate positive energy balance. In pregnancy, both the placenta and adipose tissue contribute to circulating leptin levels. We tested whether maternal leptin levels are associated with subsequent GWG and whether this association varies depending on stage of pregnancy and on maternal body mass index (BMI).

METHODS

This prospective cohort study included 675 pregnant women followed from 1(st) trimester until delivery. We collected anthropometric measurements, blood samples at 1(st) and 2(nd) trimester, and clinical data until delivery. Maternal leptin was measured by ELISA (Luminex technology). We classified women by BMI measured at 1(st) trimester: BMI < 25 kg/m(2) = normal weight; 25 ≤ BMI < 30 kg/m(2) = overweight; and BMI ≥ 30 kg/m(2) = obese.

RESULTS

Women gained a mean of 6.7 ± 3.0 kg between 1(st) and 2(nd) trimester (mid pregnancy GWG) and 5.6 ± 2.5 kg between 2(nd) and the end of 3(rd) trimester (late pregnancy GWG). Higher 1(st) trimester leptin levels were associated with lower mid pregnancy GWG, but the association was no longer significant after adjusting for % body fat (%BF; β = 0.38 kg per log-leptin; SE = 0.52; P = 0.46). Higher 2(nd) trimester leptin levels were associated with greater late pregnancy GWG and this association remained significant after adjustment for BMI (β = 2.35; SE = 0.41; P < 0.0001) or %BF (β = 2.01; SE = 0.42; P < 0.0001). In BMI stratified analyses, higher 2(nd) trimester leptin levels were associated with greater late pregnancy GWG in normal weight women (β = 1.33; SE = 0.42; P =0.002), and this association was stronger in overweight women (β = 2.85; SE = 0.94; P = 0.003--P for interaction = 0.05).

CONCLUSIONS

Our results suggest that leptin may regulate weight gain differentially at 1(st) versus 2(nd) trimester of pregnancy: at 2(nd) trimester, higher leptin levels were associated with greater subsequent weight gain--the opposite of its physiologic regulation in non-pregnancy--and this association was stronger in overweight women. We suspect the existence of a feed-forward signal from leptin in second half of pregnancy, stimulating a positive energy balance and leading to greater weight gain.

Systematic Review of the Methodological Quality of Studies Aimed at Creating Gestational Weight Gain Charts

A range of adverse outcomes is associated with insufficient and excessive maternal weight gain in pregnancy, but there is no consensus regarding what constitutes optimal gestational weight gain (GWG). Differences in the methodological quality of GWG studies may explain the varying chart recommendations. The goal of this systematic review was to evaluate the methodological quality of studies that aimed to create GWG charts by scoring them against a set of predefined, independently agreed-upon criteria. These criteria were divided into 3 domains: study design (12 criteria), statistical methods (7 criteria), and reporting methods (4 criteria). The criteria were broken down further into items, and studies were assigned a quality score (QS) based on these criteria. For each item, studies were scored as either high (score = 0) or low (score = 1) risk of bias; a high QS correlated with a low risk of bias. The maximum possible QS was 34. The systematic search identified 12 eligible studies involving 2,268,556 women from 9 countries; their QSs ranged from 9 (26%) to 29 (85%) (median, 18; 53%). The most common sources for bias were found in study designs (i.e., not prospective); assessments of prepregnancy weight and gestational age; descriptions of weighing protocols; sample size calculations; and the multiple measurements taken at each visit. There is wide variation in the methodological quality of GWG studies constructing charts. High-quality studies are needed to guide future clinical recommendations. We recommend the following main requirements for future studies: prospective design, reliable evaluation of prepregnancy weight and gestational age, detailed description of measurement procedures and protocols, description of sample-size calculation, and the creation of smooth centile charts or z scores.

Prognostic value of ambulatory blood pressure measurements for the diagnosis of hypertension in pregnancy

Several studies have indicated that the use of the 24 h mean blood pressure, mainly using reference thresholds derived from general nonpregnancy practice, does not provide an effective test for an individualized early diagnosis of hypertension in pregnancy, thus concluding that ambulatory blood pressure monitoring is not a valid approach in pregnancy. With the use of ambulatory blood pressure monitoring, epidemiologic studies have reported gender differences in the circadian variability of blood pressure and heart rate. Typically, men exhibit a lower heart rate and higher blood pressure than women, the differences being larger for systolic than for diastolic blood pressure. Moreover, normotensive and hypertensive pregnant women are characterized by differing but predictable patterns of blood pressure variability throughout gestation. However, the diminished blood pressure in nongravid women as compared with men, the added decrease in blood pressure during the second trimester of gestation in normotensive but not in hypertensive pregnant women and the large amplitude of the circadian pattern that characterizes the blood pressure of healthy pregnant women at all gestational ages, have not been taken into account when establishing reference thresholds for the diagnosis of hypertension in pregnancy. This review will describe these issues, summarize previous results from independent groups on the prognostic value of ambulatory blood pressure monitoring in pregnancy, propose answers as to an accurate reference threshold for blood pressure at different stages of gestation and suggest how this information should be used in order to identify those women at a higher risk of hypertension, who will also be more suitable for prophylactic and/or therapeutic intervention in the early stages of pregnancy.

The influence of weight gain patterns in pregnancy on fetal growth using cluster analysis in an obese and nonobese population

OBJECTIVE

Excessive weight gain during pregnancy has an important influence on fetal growth and on weight development in future generations.

DESIGN AND METHODS

A prospective cohort study of 325 obese and nonobese Caucasian women with naturally conceived, singleton pregnancies was performed. They were followed up until delivery for maternal weight gain and for fetal growth with ultrasound-based weight estimations and final birth weight. Using cluster analysis distinct profiles of maternal weight gain during pregnancy were obtained. Longitudinal regression analysis was performed to investigate the relationship of the maternal weight gain profile and BMI on fetal growth and final birth weight.

RESULTS

Cluster analysis revealed four discernable maternal weight gain profiles: 12 cases (3.7%) ended up at their starting weight or decreased in weight (cluster 1), 16 cases (4.9%) who slightly increased in weight (maximum 4 kg) as compared to their initial weight (cluster 2), 114 cases (35.1%) who gained between 4 and 12 kg in weight (cluster 3), and 183 cases (56.3%) who showed the largest weight gain: more than 12 kg (cluster 4). There were statistically significant differences in fetal growth associated with weight gain cluster, which became apparent late in the second trimester and increased toward the end of pregnancy. Maternal BMI and maternal weight gain profile were independent predictors of fetal growth and birth weight.

CONCLUSIONS

Therefore, the conclusion is that the cluster analysis permits to discern four gestational weight gain (GWG) patterns in obese and nonobese subjects and that both maternal BMI and maternal weight gain pattern during pregnancy positively influence fetal growth and birth weight.

Antenatal interventions for reducing weight in obese women for improving pregnancy outcome

BACKGROUND

Being obese and pregnant is associated with substantial risks for the mother and her child. Current weight management guidance for obese pregnant women is limited. The latest recommendations suggest that obese pregnant women should gain between 5.0 and 9.1 kg during the pregnancy period, and weight loss is discouraged. However, observational studies indicate that some obese pregnant women, especially those who are heavier, lose weight during pregnancy. Furthermore, some obese pregnant women may intentionally lose weight. The safety of weight loss when pregnant and obese is not substantiated; some observational studies suggest that risks associated with weight loss such as pre-eclampsia are improved, but others indicate that the incidence of small- for-gestational infants are increased. It is important to evaluate interventions that are designed to reduce weight in obese pregnant women so that the safety of weight loss during this period can be established.

OBJECTIVES

To evaluate the effectiveness of interventions that reduce weight in obese pregnant women.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2012) and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials, 'quasi-random' studies and cluster-randomised trials comparing a weight-loss intervention with routine care or more than one weight loss intervention. Cross-over trials were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We identified no studies that met the inclusion criteria for this review.

MAIN RESULTS

There were no included trials.

AUTHORS' CONCLUSIONS

There are no trials designed to reduce weight in obese pregnant women. Until the safety of weight loss in obese pregnant women can be established, there can be no practice recommendations for these women to intentionally lose weight during the pregnancy period. Further study is required to explore the potential benefits, or harm, of weight loss in pregnancy when obese before weight loss interventions in pregnancy can be designed. Qualitative research is also required to explore dietary habits of obese pregnant women, especially those who are morbidly obese.

Rate and pattern of weight gain in Indian women from the upper income group during pregnancy and its effect on pregnancy outcome

Maternal weight gain and pattern of weight gain during pregnancy influence the ultimate outcome of pregnancy. Pregravid body mass index (BMI), maternal dietary intake, maternal height and age all determine the weight gain during pregnancy. The study was taken up with an objective to observe maternal weight gain and its pattern in pregnancy in women from an upper income group and to find out their association with pregnancy outcome. 180 normal primiparous pregnant Indian women (20-35 years) from an upper income group were recruited between the 10th and 14th weeks of pregnancy and were followed up throughout their pregnancy to record total and trimester-wise weight gain. Neonatal birth weights were recorded. The results showed that mothers with high pregravid BMI gained more weight during pregnancy than the recommended weight gain; in addition, weight gain in the first trimester was significantly correlated with birth weight of the neonates (P = 0.019). Significant correlation was found between weight gain in the third trimester and birth weight of the neonate irrespective of maternal BMI. The rate of weight gain was significantly correlated with neonatal birth weights irrespective of maternal pregravid BMI (P = 0.022) and as per its categories (P = 0.027). Thus, overall it can be concluded that adequate maternal nutrition before and during pregnancy is important for adequate weight gain by the mother and can result in better outcome of pregnancy. The rate of weight gain is also an important contributing factor.

Recognition of novel faces after single exposure is enhanced during pregnancy

Protective mechanisms in pregnancy include Nausea and Vomiting in Pregnancy (NVP) (Fessler, 2002; Flaxman and Sherman, 2000), increased sensitivity to health cues (Jones et al., 2005), and increased vigilance to out-group members (Navarette, Fessler, and Eng, 2007). While common perception suggests that pregnancy results in decreased cognitive function, an adaptationist perspective might predict that some aspects of cognition would be enhanced during pregnancy if they help to protect the reproductive investment. We propose that a reallocation of cognitive resources from nonessential to critical areas engenders the cognitive decline observed in some studies. Here, we used a recognition task disguised as a health rating to determine whether pregnancy facilitates face recognition. We found that pregnant women were significantly better at recognizing faces and that this effect was particularly pronounced for own-race male faces. In human evolutionary history, and today, males present a significant threat to females. Thus, enhanced recognition of faces, and especially male faces, during pregnancy may serve a protective function.

Antenatal interventions for reducing weight in obese women for improving pregnancy outcome

This is the protocol for a review and there is no abstract. The objectives are as follows: To evaluate the effectiveness of interventions that reduce weight in obese pregnant women.

Maternal obesity and infant outcomes

Obesity (Body mass index (BMI) above 30) is one of the major health issues of the 21st century. Over 1.1 billion of the world's population are now classified as obese. In the UK, women are more likely to be obese than men; over 50% of women of reproductive age are overweight or obese. Maternal obesity and the plethora of associated conditions, have a serious impact on the health and development of their offspring. In this review we describe the direct and indirect impact of maternal obesity on the health of the baby. Maternal obesity affects conception, duration and outcome of pregnancy. Offspring are at increased risk of both immediate and long term implications for health. We also briefly review potential mechanisms drawing on data from human and animal studies, and on the outcomes of clinical interventional studies.

Increased pregnancy weight gain in women with latent toxoplasmosis and RhD-positivity protection against this effect

OBJECTIVE

RhD-positive subjects are protected against toxoplasmosis-associated impairment of psychomotor performance. Here we searched for RhD-positivity-associated maternal protection against the effects of toxoplasmosis.

METHODS

In the present retrospective cohort study, we analysed data from 785 (139 RhD-negative) Toxoplasma-free and 194 (27 RhD-negative) Toxoplasma-infected pregnant women. We searched for effects of toxoplasmosis and Rhd-phenotype on maternal weight before pregnancy, pregnancy weight gain, fetal ultrasound data (biparietal diameter, abdominal circumference, femur length) and on birth length and weight.

RESULTS

At pregnancy week 16, the RhD-negative mothers with toxoplasmosis gained more weight than others (P < 0.001). The difference of about 1600 g remained approximately constant from pregnancy week 16 until the end of pregnancy. Neither toxoplasmosis nor RhD phenotype had any effect on fetal bioparameter data or birth length and weight.

CONCLUSION

The most parsimonious explanation for the observed data is that the RhD-positive phenotype might protect infected subjects against a broad spectrum of detrimental effects of latent toxoplasmosis, including excessive gestational weight gain.

Ganho ponderal e desfechos gestacionais em mulheres atendidas pelo Programa de Saúde da Família em Campina Grande, PB (Brasil)

OBJETIVO: Descrever o ganho ponderal e sua associação com os desfechos gestacionais em gestantes do Programa de Saúde da Família no município de Campina Grande, PB. MÉTODOS: Trata-se de um estudo longitudinal prospectivo desenvolvido de março de 2005 a março de 2006. O peso gestacional foi avaliado a cada quatro semanas a partir da 16ª semana gestacional. O cálculo do índice de massa corporal seguiu os critérios de Atalah (1997), adotados pelo Ministério da Saúde, e o ganho ponderal foi avaliado segundo recomendações do Institute of Medicine (1990). RESULTADOS: O estudo foi concluído com 118 gestantes, entre as quais a média de idade foi de 23 anos. As incidências de ganho de peso excessivo, no segundo e no terceiro trimestres, foram iguais a 44% e a 45%, respectivamente. A hipertensão arterial gestacional foi observada em 8,5% da amostra, sendo estatisticamente significante a sua associação com o estado nutricional inicial (p=0,02). Não houve casos de diabetes gestacional e 34% das gestantes tiveram partos cirúrgicos. O estado nutricional inicial de sobrepeso/obesidade, bem como o ganho de peso excessivo nos dois trimestres estudados, apresentou associação significante com o estado nutricional pós-parto (p<0,001). CONCLUSÃO: A alta incidência de ganho de peso gestacional excessivo na coorte estudada e a associação do sobrepeso/obesidade inicial com os desfechos maternos são preocupantes e merecem a atenção dos serviços locais de saúde devido às suas implicações para a saúde da mãe e do feto.

How should gestational weight gain be assessed? A comparison of existing methods and a novel method, area under the weight gain curve

BACKGROUND

Gestational weight gain is important to assess for epidemiological and public health purposes: it is correlated with infant growth and may be related to maternal outcomes such as reproductive health and chronic disease risk. Methods commonly used to assess weight gain incorporate assumptions that are usually not borne out, such as a linear weight gain, or do not account for differential length of gestation.

METHODS

We introduce a novel method to assess gestational weight gain, the area under the weight gain curve. This is easily interpretable as the additional pound-days carried due to pregnancy and avoids many flaws in alternative assessments. We compare the performance of the simple difference, weekly gain, Institute of Medicine categories and the area under the weight gain curve in predicting birthweight and maternal weight retention at 6, 12, 24 and 36 months postpartum. The analytic sample comprises 2016 participants in Project Viva, an observational prospective cohort study of pregnant women in Massachusetts.

RESULTS

For birthweight outcomes, none of the weight gain measures is a meaningfully superior predictor. For 6-month postpartum weight retention the simple difference is superior, while for 12-, 24- and 36-month weight retention the area under the weight gain curve is superior.

CONCLUSIONS

These findings are plausible biologically: the same amount of weight gained early vs later in the pregnancy may reflect increased maternal fat stores. The timing of weight gain is reflected best in the area under the weight gain curve. Different methods of measuring gestational weight gain may be appropriate depending on the context.

Determinantes do ganho ponderal excessivo durante a gestação em serviço público de pré-natal de baixo risco

INTRODUÇÃO: O excesso de ganho de peso durante a gestação pode ocasionar retenção de peso pós-parto e contribuir para a obesidade no sexo feminino. METODOLOGIA: Neste estudo, avaliou-se a influência de fatores sociodemográficos, história gestacional, tabagismo, trabalho fora de casa e estado nutricional inicial sobre o ganho ponderal excessivo (GPE). O GPE foi estimado a partir das. recomendações do IOM (ganho semanal >0,58g, >0,53g e >0,39g, correspondentes a estado de nutricional no início da gestação: desnutrida, adequada e sobrepeso/obesidade, respectivamente). Estudou-se uma coorte de 141 gestantes saudáveis, inscritas em serviço público de pré-natal, entre março de 1997 e março de 1998. A influência dos fatores de estudo sobre o GPE foi testada separadamente no 2º e 3º trimestres mediante análise de regressão de Poisson múltipla hierarquizada. RESULTADOS: Dentre as 237 elegíveis houve 37,8% de perdas, não se detectando diferenças estatisticamente significativas para as variáveis centrais do estudo. A incidência de GPE no 2º trimestre foi de 38,6% (IC95% 30,5 - 47,2) e no 3º trimestre foi de 36,4% (IC95% 28,5 - 45,0). No 2º trimestre, apenas a escolaridade mostrou-se associada ao GPE. Em relação às mulheres com menos de 5 anos de escolaridade, as gestantes com 5 a 8 anos e acima de 8 anos de escolaridade apresentaram riscos relativos correspondentes a 2,09 (IC95% 1,03 - 4,25) e 2,62 (IC95% 1,32 - 5,22), respectivamente. No 3º trimestre mostraram significância estatística as variáveis: escolaridade >8 anos (RR=1,91 [IC95% 1,22 - 2,97], ausência de companheiro (RR=1,66 [(IC95% 1,06 - 2,59], primiparidade (RR=2,13 [IC95% 1,20 - 3,85] e estado nutricional inicial adequado e sobrepeso/obesidade (RR=1,53 [IC95% 0,82 _ 2,84] e RR=2,02 [IC95% 1,04 - 3,92], respectivamente) em relação às desnutridas. CONCLUSÃO: Em função da elevada freqüência de GPE, particularmente em mulheres de escolaridade mais alta, as sem companheiro, as primíparas e aquelas com estado nutricional inicial adequado ou sobrepeso/obesidade durante a gestação, mais atenção deveria ser dada à prevenção e ao controle do problema durante o pré-natal.

Cross-sectional study of weight gain and increase in BMI throughout pregnancy

OBJECTIVE

To generate reliable new reference ranges for weight gain and increase in body mass index (BMI) during pregnancy from a large population.

STUDY DESIGN

In a prospective cross-sectional study at the Obstetric outpatient clinic, Zurich University Hospital, weight gain and BMI, before gestation and at the booking visit, were determined in 4034 pregnant women with accurately dateable singleton pregnancies (Caucasian: N = 3242, Asian (predominantly from Sri Lanka, Thailand and the Philippines): N = 578 and Black: N = 214). Women with known insulin-dependent diabetes mellitus before pregnancy were excluded. Fifth, 50th and 95th centiles were presented for Caucasians and corresponding centile curves for Asians and Blacks. Simple and multiple regression analyses were performed for various risk factors. A significance level of P < 0.05 was used in all tests.

RESULTS

Mean weight gain was 15.5+/-5.9 kg (34.2+/-13.0 lb) at term with values >25.4 kg (56.0 lb) and <5.7 kg (12.6 lb) for the 95th and the 5th centile, respectively. Mean BMI increased slightly and steadily to 28 kgm(-2) at term. Parity and pre-pregnancy BMI were significant determinants in Caucasians. Weight gain and BMI was slightly lower in Asians and Blacks.

CONCLUSIONS

BMI centile curves have the advantage in that they consider height during the whole course of pregnancy. It may be an additional helpful tool in controlling weight gain in pregnancy. Further studies are required to determine the prognostic implications of values > or = 95th centile and < or = 5th centile.

Weight Change and the Risk of Gestational Diabetes in Obese Women

BACKGROUND

Obesity is an established risk factor for gestational diabetes. It is not known whether this risk might be reduced through weight loss between pregnancies. We sought to determine whether weight loss between pregnancies reduced the risk of gestational diabetes among obese women.

METHODS

We conducted a population-based cohort study of 4102 women with 2 or more singleton live births in Washington State between 1992 and 1998. All subjects were nondiabetic and obese (at least 200 lbs) at their first birth during these years. Weight change was calculated as the difference between prepregnancy weight for the 2 pregnancies. We estimated relative risks of gestational diabetes at the subsequent delivery through stratified analyses and Mantel-Haenszel estimates.

RESULTS

Thirty-two percent of women lost weight between pregnancies, with a mean weight loss of 23 lbs. Women who lost at least 10 lbs between pregnancies had a decreased risk of gestational diabetes relative to women whose weight changed by less than 10 lbs (relative risk = 0.63; 95% confidence interval = 0.38-1.02, adjusted for age and weight gain during each pregnancy). Of the 61% of women who gained weight between pregnancies, the mean weight gain was 22 lbs. Women who gained at least 10 lbs had an increased risk of gestational diabetes (1.47; 1.05-2.04).

CONCLUSIONS

Even moderate changes in prepregnancy weight can apparently affect the risk of gestational diabetes among obese women. This may offer further motivation for interventions aimed at reducing obesity among women of reproductive age.

Determination of Maternal Body Composition in Pregnancy and Its Relevance to Perinatal Outcomes

Three models and 10 specific methods for determining maternal body composition are discussed and their perinatal relevance reviewed. English language publications (1950 to January 2004) were searched electronically and by hand. Search terms included "body composition," "human," " pregnancy," "obesity," "adiposity," "regional," "2-, 3-, 4-component," "truncal," "peripheral," "central," "visceral" along with specific techniques and outcomes listed subsequently. Three models of body composition are described: 2-component being fat and fat-free mass; 3-component being fat, water, and protein; and 4-component being fat, water, protein, and osseous mineral. Ten techniques of body composition assessment are described: 1) anthropometric techniques including skinfold thicknesses and waist-hip ratio; 2) total body water (isotopically labeled); 3) hydrodensitometry (underwater weighing); 4) air-displacement plethysmography; 5) bio-impedance analysis (BIA); 6) total body potassium (TBK); 7) dual-energy x-ray absorptiometry (DEXA); 8) computed tomography (CT); 9) magnetic resonance imaging (MRI); and 10) ultrasound (USS). Most methods estimate total adiposity. Regional fat distribution-central (truncal) compared with peripheral (limb) or visceral compared with subcutaneous-is important because of regional variation in adipocyte metabolism. Skinfolds, DEXA, CT, MRI, or USS can distinguish central from peripheral fat. CT, MRI, or USS can further subdivide central fat into visceral and subcutaneous. Perinatal outcomes examined in relation to body composition include pregnancy duration, birth weight, congenital anomalies, gestational diabetes, gestational hypertension, and the fetal origins of adult disease. A few studies suggest that central compared with peripheral fat correlates better with birth weight, gestational carbohydrate intolerance, and hypertension. Means of accurately assessing maternal body composition remain cumbersome and impractical, but may more accurately predict perinatal outcomes than traditional assessments such as maternal weight.

Circadian rhythm of blood pressure challenges office values as the "gold standard" in the diagnosis of gestational hypertension

Despite poor sensitivity and specificity, office blood pressure (BP) determinations are still the "gold standard" for diagnosing gestational hypertension. This prospective blind study evaluates the prognostic value of office values as compared with ambulatory monitoring in pregnancy. We analyzed 2175 BP series systematically sampled from 355 non-preeclamptic pregnant women for 48 h every 4 wks from the first hospital visit until delivery. Women were divided for comparative purposes into three groups: "detected" gestational hypertension, defined on the basis of casual clinical BP> 140/90 mmHg after 20 wks of gestation and hyperbaric index (area of BP excess above the upper limit of a time-specified tolerance interval adjusted for the circadian pattern of the reference population) consistently above the threshold for diagnosing hypertension in pregnancy; "undetected" gestational hypertension, women with office BP < 140/90 mmHg but hyperbaric index consistently above the threshold for diagnosis; and normotension, women with both office values and hyperbaric index below the respective thresholds for diagnosis. Small and insignificant differences in the 24h mean BP between "detected" and "undetected" gestational hypertension is observed in all trimesters, in contrast with highly significant differences between these two groups and normotensive pregnancies. Normotensive women are characterized by highly significant lesser incidence by 60% in preterm delivery, 70% in intrauterine growth retardation, and 50% in delivery by cesarean section (p < 0.001) compared with women with "detected" and "undetected" gestational hypertension (p > 0.715). In pregnancy, the hyperbaric index is markedly superior to office BP measurements for diagnosis of what should be truly considered gestational hypertension, and for prediction of the outcome of pregnancy.

Weight-gain patterns from prepregnancy until delivery among women in Central Java, Indonesia

BACKGROUND

Representative data on pregnancy weight-gain patterns from developing countries are scarce. The reasons include difficulties in obtaining population-based samples and in collecting data before and throughout pregnancy.

OBJECTIVE

The objective was to measure weight-gain patterns from prepregnancy until after delivery in a population-based sample of rural Indonesian women.

DESIGN

Two cross-sectional surveys of nutritional status among nonpregnant women of reproductive age were carried out through a surveillance system in Purworejo District, Central Java, Indonesia, in 1996 and 1997. Between 1996 and 1998, 846 newly pregnant women were enrolled in a cohort study in which weight was monitored monthly throughout pregnancy. Prepregnancy weights and other anthropometric measures were available for 251 of the women who had live births.

RESULTS

Before pregnancy, 16.7% of the women had chronic energy deficiency and 10.0% were obese. The mean total pregnancy weight gain for all the women was 8.3 +/- 3.6 kg, and 79% did not meet the international recommendation regarding weight gain for their prepregnant body mass index. The rate of weight gain was highest during the second trimester (0.34 kg/wk). In the first and third trimesters, it was 0.08 and 0.26 kg/wk, respectively. Total weight gain was associated with prepregnant body mass index, education, and socioeconomic status.

CONCLUSIONS

Many women in rural Central Java, Indonesia, enter pregnancy with suboptimal nutritional status. For most of these women, total weight gain during pregnancy is insufficient. It is likely that this contributes to adverse health outcomes for both the mothers and their newborns.

Psychosocial thriving during late pregnancy: relationship to ethnicity, gestational weight gain, and birth weight

OBJECTIVE

To test the relationships between psychosocial thriving (depressive symptoms, health-related lifestyle) and gestational weight gain and birth weight. To test the influences of ethnicity on the relationships between psychosocial thriving and gestational weight gain and birth weight.

DESIGN

Baseline data taken from the Austin New Mothers Study.

SETTING

A community hospital in Texas.

PARTICIPANTS

305 low-risk African American, Hispanic, and White women with full-term pregnancies, singleton births, and Medicaid coverage.

MAIN MEASURES

Center for Epidemiologic Studies Depression Scale, Self Care Inventory, Food Habits Questionnaire, gestational weight gain, and birth weight.

RESULTS

Newborns of African American women had lower birth weights (3,240 g) than newborns of Hispanic (3,422 g) or White women (3,472 g), even though no ethnic differences were found among the mothers on psychosocial variables. Late in pregnancy, women had high levels and prevalence (> 70%) of depressive symptoms regardless of ethnicity, and 50% exceeded recommended gestational weight gains. In full regression models, psychosocial variables were not significant predictors of gestational weight gain or birth weight. Ethnicity also was not a significant moderator of weight outcomes.

CONCLUSIONS

Psychosocial thriving late in pregnancy was unrelated to gestational weight gain or birth weight. Ethnicity did not moderate psychosocial-weight relationships. Although ethnic differences were not found on psychosocial variables, high levels of depressive symptoms and greater than recommended gestational weight gains were prevalent. These findings have implications for maternal health during and beyond pregnancy.

Intrauterine growth retardation index

SUMMARY

The objective of the study discussed was to develop an intrauterine growth retardation (IUGR) index to detect fetuses with IUGR. The study was conducted in Australia and was based on 219 pregnant women at Wollongong Hospital in the Illawarra region in New South Wales, Australia. Overall, 21 variables, including ultrasonographic variables and risk factors for IUGR, related to IUGR were tested in the sample. The results of discriminant analysis showed that hypertension, amniotic fluid index, abdominal circumference, head circumference, head circumference-to-abdominal circumference ratio, and low maternal weight gain in pregnancy have the highest F values. That means that these parameters were the most important predictors of IUGR in fetuses. An IUGR score was developed using these parameters. The developed index in this study has a reasonably high sensitivity (89.1%) and specificity (71.8%) in detecting IUGR in fetuses, compared with the developed indices to date. The IUGR score includes both ultrasonographic and maternal risk factor variables. This combination increases the accuracy of identification of IUGR in fetuses.

Predictable blood pressure variability in healthy and complicated pregnancies

With the aim of describing the predictable pattern of blood pressure (BP) variability during gestation, we analyzed 2430 BP series systematically sampled by ambulatory monitoring for 48 consecutive hours every 4 weeks from the first obstetric visit (usually within the first trimester of pregnancy) until delivery in 235 normotensive women, 128 women who developed gestational hypertension, and 40 women who had a final diagnosis of preeclampsia. The pattern of variation along gestation of the 24-hour means of BP and heart rate was established for each group of women by polynomial regression analysis. For normotensive women, results indicate a steady decrease in BP up to 20 weeks of pregnancy, followed by an increase in BP up to the day of delivery, with an average 8% BP increase between the middle of gestation and delivery. In complicated pregnancies, BP is stable until the 22nd week of gestation and then increases linearly for the remainder of the pregnancy. Complicated pregnancies are characterized by a 9% and 13% increase in systolic and diastolic BPs, respectively, during the second half of gestation. Results also indicate that during the first half of pregnancy, systolic but not diastolic BP is slightly elevated in women who developed preeclampsia compared with those who developed gestational hypertension. During the second half of gestation, the linear trend of increasing BP for women who developed preeclampsia has a significantly higher slope than the trend for women with gestational hypertension. For both healthy and complicated pregnancies, heart rate increases until the end of the second trimester and slightly decreases thereafter. This study of women systematically sampled by 48-hour ambulatory BP monitoring throughout gestation confirms the predictable pregnancy-associated variability in BP and provides proper information for the establishment of reference limits for BP to be used in the early diagnosis of hypertensive complications in pregnancy. Those limits should be developed as a function of gestational age, taking into account the trends in BP throughout pregnancy demonstrated here.

The construct of thriving in pregnancy and postpartum

This article explores the construct of thriving as an integration of nutritional (manifested in weight), psychosocial, and lifestyle concerns of childbearing within the context of Orem's self-care deficit theory. Provisional definitions of thriving in pregnancy and postpartum are proposed. Preliminary dimensions of thriving in postpartum are based on factor analysis of weight, lifestyle, and psychosocial data from 145 women after childbirth. Four dimensions emerged: psychosocial distress, lifestyle patterns, a weight factor, and a body image factor. Although the dimensionality of postpartal thriving reported is preliminary, it provides a beginning foundation for assessment and intervention for postpartal women.

The views of women of above average weight about appropriate weight gain in pregnancy

OBJECTIVE

To examine the beliefs of women of above average weight about appropriate levels of weight gain in pregnancy.

DESIGN

An in-depth qualitative study of 37 women.

SETTING

Women recruited from a city hospital, a rural hospital and by community midwives in the south of England.

PARTICIPANTS

Women were identified via hospital notes or by community midwives. Over a one-year period all women identified who attained the weight of 90 kg by the 30th week of pregnancy were eligible to participate. The sample comprised 37 women. The sample was varied in terms of age, social class, household composition and number of children.

MEASUREMENT

Two in-depth interviews were carried out with each interviewee: during late pregnancy and six weeks following childbirth.

FINDINGS

Interviewees were concerned not to weigh more after pregnancy than before. Their perceived ability to control weight gain during pregnancy was varied. In the perceived absence of specific advice from health professionals, they constructed their own views about appropriate levels of weight gain. These were informed by their desire to minimise weight gain and to provide adequate nourishment for the growth and development of their baby. Comments and advice from health professionals were interpreted within the women's own understandings of appropriate levels of weight gain.

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

(1) the desire to return to their pre-pregnancy weight was a strong motivating factor among pregnant women of above average weight, but some women lacked confidence in their ability to control weight gain; (2) the health and well-being of their unborn baby is often a central concern in women's decisions about appropriate weight gain; (3) health professionals need to explore the beliefs of women of above average weight about appropriate weight gain in pregnancy; and (4) written information about weight gain may assist women of above average weight in understanding what might be an appropriate level of weight gain during pregnancy.

Prepregnant weight and weight gain during pregnancy: relationship to functional status, symptoms, and energy

OBJECTIVE

To examine the relationship of prepregnancy weight and pregnancy weight gain to functional status, physical symptoms, and physical energy.

DESIGN

Longitudinal panel, with data collected at the end of each trimester. Functional status was measured by the Inventory of Functional Status-Antepartum Period; physical symptoms, by the Symptoms Checklist; and physical energy, by a one-item question. Self-reported weight and height were used to calculate body mass index (BMI), using the formula weight[kg]/height[m2].

SETTING

Women's homes.

PARTICIPANTS

Two hundred twenty-two women, whose pregnancies were low-risk, drawn from a larger study.

RESULTS

Women were classified by prepregnancy BMI as underweight (BMI < 19.8), normal weight (BMI = 19.8-26.0), or overweight (BMI > 26.0). The groups did not differ in weight gain by trimester, for an average total weight gain of 30.56 lb (SD = 10.18, range = 1-64) (p > .05), with overweight women therefore gaining less weight on a percentage basis (M = 16.87%) than women who were of normal weight (M = 23.58%) or were underweight (M = 26.02%) (p < .00005). The groups did not differ in functional status, physical energy, or number or type of physical symptoms. Women who gained more than the recommended amount of weight for their prepregnant weight group had a lower level of 3rd trimester functional status than those who did not.

CONCLUSIONS

Individual counseling of women regarding food intake and excessive weight gain during pregnancy needs to be reconsidered in light of these findings.

Maternal anthropometry and pregnancy outcome among Jerusalem women

Maternal anthropometry, expressed in terms of height, prepregnancy weight and weight gain during pregnancy was studied in 432 Israeli mothers who attended routinely the Hadassah Community Health Centre in Jerusalem, and delivered live births from 1990 to 1994. Among the variables studied, social class was positively associated to mother's height. From five curves fitted with gestational age and weight gain of each woman, a quadratic one was chosen to describe the weight gain pattern of the population. From the model, prepregnancy weight and the weekly rate of weight gain were calculated. Height was positively associated to the rate of weight gain. Gestational age at delivery and gender were the strongest predictors of birth weight, followed by height and rate of weight gain. Three patterns of weight gain were observed: concave, linear and convex. No one of the variables studied was related to the pattern of weight gain as determinant or consequence. Since not all the patterns follow the same shape, the interpretation of adequacy of weight gain at a certain gestational age by using available standards must be done carefully until further studies clarify the relationships between patterns of weight gain and pregnancy outcomes for this population. Prospective studies should be carried out in Israel to control for several factors influencing maternal anthropometry and pregnancy outcomes.

The usefulness of a weight gain spurt to identify women who will develop preeclampsia

OBJECTIVE

The usefulness of adaptive centiles for weight gain as well as sudden weight gain spurts in identifying women who will develop preeclampsia was assessed.

METHODS

A study sample of 99 women who developed preeclampsia and a control sample of 675 women with normal pregnancies, were randomly selected. Weight gain spurts were identified by the upper bound of adaptive maternal weight centiles. Average changes in weight between successive clinic visits were also assessed.

RESULTS

Weight gain exceeding the 90th percentile of the adaptive centiles resulted in estimated sensitivity and specificity of 52% and 66% and weight gain >0.9 kg per week between visits in 76% and 29% respectively. Of women who would develop preeclampsia identified by the adaptive chart, 62.0% exhibited abnormal weight gain prior to the onset of abnormal clinical findings.

CONCLUSIONS

A sudden weight gain spurt is a far from reliable sign of impending preeclampsia. This reason for weighing women at antenatal visits appears to be unfounded.

Prenatal weight gain patterns and infant birthweight associated with maternal smoking

BACKGROUND

Maternal smoking during pregnancy is recognized as an important and modifiable risk factor for low infant birthweight. The objective of this study was to compare the effects of maternal smoking status on prenatal weight gain and infant birthweight, and to determine if maternal weight gain mediates the effect of smoking cessation on infant birthweight.

METHODS

This prospective study of 341 white, non-Hispanic pregnant smokers, never smokers, and women who stopped smoking during pregnancy used multivariate analysis of variance to evaluate prenatal weight gain patterns. Multiple regression was used to investigate the effects of smoking status and maternal weight gain on infant birthweight.

RESULTS

Women who stopped smoking gained on average 39.68 lb during pregnancy. Smokers gained 32.75 lb, and never smokers gained 34.16 lb. Women who stopped gained significantly more weight than both smokers and never smokers (p = 0.01). Rates of weight gain differed significantly beginning in the second trimester, when women who stopped smoking gained more weight than never smokers (2.57 lb, 99% CI = 0.46, 8.07) and continued during the third trimester, with those who stopped smoking gaining more weight than both smokers (4.31 lb, 99% CI = 1.88, 12.00) and never smokers (1.25 lb, 99% CI = 0.56, 10.49). Infant birthweight differences were significant for women who stopped smoking versus continuing smokers (292 g, 99% CI = 145, 440) and for never smokers versus continuing smokers (253 g, 99% CI = 104, 401). Controlling for baseline maternal body mass index and infant gender, smoking status and weight gain each contributed significantly to infant birthweight (p < 0.001). No evidence of interaction between smoking status and weight gain on infant birthweight was found.

CONCLUSIONS

Maternal smoking status significantly affects prenatal weight gain and infant birthweight, but smoking cessation protects against lower birthweight through mechanisms other than increased maternal weight gain or different weight gain patterns.

The pattern of maternal weight gain in women with good pregnancy outcomes

OBJECTIVES

This study describes the pattern of maternal weight gain in women with good pregnancy outcomes and provides data to fill in the provisional weight-gain charts published by the Institute of Medicine (IOM) in 1990.

METHODS

We selected 7002 women with good outcomes (defined by factors related to maternal and infant health) from the University of California, San Francisco, Perinatal Database. For each body mass index category, we compared percentiles of weight gain by trimester in women who achieved the IOM recommendations for total gain and those who did not.

RESULTS

Trimester rates of gain varied by body mass index category and exceeded IOM guidelines in all groups. Forty percent of these women with good outcomes had total gains within the guidelines and provided data to complete the IOM weight-gain charts.

CONCLUSIONS

Most women in this good-outcome sample would have been suspected of being at increased risk for poor outcome on the basis of their weight gain. This confirms the IOM recommendation that evaluation of the underlying causes of excessively high or low weight gain during pregnancy is necessary before appropriate interventions can be applied.

Predictors of poor maternal weight gain from baseline anthropometric, psychosocial, and demographic information in a Hispanic population

OBJECTIVE

To identify which baseline factors best predict poor maternal weight gain among Hispanics.

SAMPLE

Pregnancy and outcome data collected prospectively from 4,791 Hispanic women attending public prenatal clinics in West Los Angeles, Calif, from 1983 through 1986.

METHODS

Prepregnancy weight was categorized into weight status groups using body mass index (BMI). Poor total weight gain (based on a mean gestational age at last measurement, which was at 35 weeks) was defined as less than 21 lb for women with BMI less than 26 and less than 10 lb for women with BMI of 26 or greater. Analyses used Student's t test, chi 2, and multivariate regression techniques (linear and logistic).

RESULTS

Poor total weight gain was identified in 29% of the women. For women who were underweight or normal weight before pregnancy, the only factor associated with increasing the risk of poor total weight gain was short stature (adjusted odds ratio [AOR] = 1.5, 95% confidence interval [CI] = 1.24, 1.84). The following factors decreased the risk: being US born (AOR = 0.61, 95% CI = 0.37, 1.00); being primiparous and under 29 years old (for < 20 years AOR = 0.69, 95% CI = 0.51, 0.92 and for 20 to 29 years AOR = 0.63, 95% CI = 0.49, 0.81); planning the pregnancy (AOR = 0.82, 95% CI = 0.67, 1.00); and having a close relative die during the pregnancy (AOR = 0.65, 95% CI = 0.44, 0.95). For obese and overweight women, physical abuse by the baby's father increased the risk (AOR = 3.19, 95% CI = 1.27, 8.01) of poor total weight gain, whereas receiving financial support from the baby's father decreased the risk (AOR = 0.59, 95% CI = 0.37, 0.95).

APPLICATIONS/CONCLUSIONS

These baseline factors could aid in targeting nutrition and other social services earlier to pregnant Hispanic women. By strategically targeting pregnant women in greatest need of services, improvements in birth outcomes may be enhanced.

Risk factors associated with preeclampsia in healthy nulliparous women. The Calcium for Preeclampsia Prevention (CPEP) Study Group

OBJECTIVE

Our goal was to identify risk factors for the development of preeclampsia in nulliparous women enrolled in a multicenter trial comparing calcium supplementation to a placebo.

STUDY DESIGN

A total of 4589 women from five centers was studied. Analysis of risk factors for preeclampsia was performed in 4314 who carried the pregnancy to > 20 weeks. Baseline systolic and diastolic blood pressure, demographic characteristics, and findings after randomization were examined for the prediction of preeclampsia. Preeclampsia was defined as hypertension (diastolic blood pressure > or = 90 mm Hg on two occasions 4 hours to 1 week apart) and proteinuria (> or = 300 mg/24 hours, a protein/creatinine ratio > or = 0.35, one dipstick measurement > or = 2+ or two dipstick measurements > or = 1+ at an interval as specified for diastolic blood pressure).

RESULTS

Preeclampsia developed in 326 women (7.6%). The first analysis treated each risk factor as a categoric variable in a univariate regression. Maternal age, blood group and Rh factor, alcohol use, previous abortion or miscarriage, private insurance, and calcium supplementation were not statistically significant. Risk factors initially found to be significant were body mass index, systolic blood pressure, diastolic blood pressure, non-white race (African-American and other), clinical center, and smoking. Adjusted odds ratios computed with a logistic regression model revealed that body mass index (odds ratio 3.22 for > or = 35 kg/m2 vs < 19.8 kg/m2), systolic blood pressure (odds ratio 2.66 for > or = 120 vs < 101 mm Hg), diastolic blood pressure (odds ratio 1.72 for > or = 61 mm Hg vs < 60 mm Hg), and clinical center (odds ratio 1.85 for Memphis vs the other clinical centers) were statistically significant predictors of preeclampsia. Results of the final model fit revealed that preeclampsia risk increases significantly (p < 0.0001) with increased body mass index at randomization, as well as with increased systolic and diastolic blood pressure at randomization. Calcium supplementation had no effect on the risks posed by body mass index and blood pressure. Among risk factors developing after randomization, an abnormal results of a glucose screen (plasma glucose > or = 140 mg/dl 1 hour after a 50 gm glucose challenge) was not found to be associated with a significant risk of preeclampsia.

CONCLUSION

These risk factors should be of value in counseling women regarding preeclampsia and should aid in understanding the pathophysiologic characteristics of this syndrome.

Maternal body mass, proportional weight gain, and fetal growth in parous women

This study is designed to examine the impact of maternal body mass index (BMI), proportional weight gain, and other variables on fetal growth. From a 10% random sample of 5722 Norwegian and Swedish para one and two women (n = 561), three hundred and sixty-nine women for whom prepregnant weight and height were recorded and for whom four fetal ultrasound measurements were taken at 17, 25, 33, and 37 weeks of gestation, were divided into low, average, and high body mass index groups (weight/height2). Fetal growth rate (mm/day) was determined by taking the mean of three measurements of the sagital and transverse diameters of the fetal abdomen (MAD) in each of three study time periods: weeks 17 to 25, first period; weeks 25 to 33, second period; weeks 33 to 37, third period. Proportional weight gain (kilograms gained within a specific time period/prepregnant weight) was measured in those same intervals. Fetal growth rate was significantly slower in the first and second periods, and significantly faster in the third time period for women with a low BMI, compared with those of average BMI. Fetal growth also significantly increased with increases in proportional weight gain in the second and third periods, but not in the first. Fetal growth appears to be independently associated with maternal BMI and proportional maternal weight gain.

The effect of social deprivation on birthweight, excluding physiological and pathological effects

OBJECTIVE

To study the effect of social deprivation on birthweight, excluding the effect of known physiological factors and exploring the effect of possible pathological factors.

DESIGN

Retrospective analysis of computerised obstetric database.

SETTING

Two teaching hospitals and an associated district general hospital which provided a defined catchment area in the East Midlands.

SUBJECTS

The final analysis included 7493 women with complete datasets and gestations of between 259 and 300 days at delivery, dated by ultrasound scan.

MAIN OUTCOME MEASURES

Smoking habit, alcohol consumption, weight gain during pregnancy, systolic and diastolic blood pressures at booking, bleeding during pregnancy and Jarman score; also, the effect of these variables on birthweight, adjusted for the effects of physiological factors using the individualised birthweight ratio.

RESULTS

Smoking during pregnancy reduced birthweight but the effect is not linear, becoming less marked as the number of cigarettes smoked increases. Alcohol intake, diastolic and systolic blood pressures at the booking visit and vaginal bleeding during early pregnancy were not significantly related to birthweight. Pregnancy weight gain was significantly positively related to birthweight especially in the normal weight range (60-99 kg). A multivariate analysis including physiological and pathological factors found increasing Jarman score to be negatively related to birthweight.

CONCLUSIONS

In this central British population social deprivation is correlated negatively with birthweight: the most socially deprived mothers have the smallest babies. This association cannot be explained in terms of physiological differences in the population nor in a higher prevalence of known pathological factors.

Clinical birthweight standards for a total population in the 1980s

OBJECTIVE

To derive clinical standards for singleton birthweight in a population based on area of residence.

DESIGN

Analysis of variables recorded in Aberdeen Maternity and Neonatal Databank, calculating for each birth a standardised birthweight score, taking account of determining factors.

SUBJECTS

All singleton live births of 32 to 42 weeks gestation to Aberdeen City District residents from 1979 to 1983.

RESULTS

Basic standards of birthweight are presented correcting for gestational age, sex of the baby and parity of the mother. Birthweight is not normally distributed and empirical data are presented rather than smoothed curves. Adjustment for maternal height is straightforward but adjustment for maternal weight must take account of the gestation at which the woman was weighed. A method of calculating the appropriate correction for height and weight is described in detail.

CONCLUSION

Birthweight is not normally distributed at each week of gestation. Standardisation for parity, gestation and sex of the baby is essential, but adjustment for maternal size is complex.