Relationship of maternal obesity and vitamin D concentrations with fetal growth in early pregnancy

Purpose

To evaluate the effects of the association between first trimester vitamin D (VitD) concentrations and increased prepregnancy body mass index (BMI) on early fetal growth restriction (FGR).

Methods

This retrospective cohort study included 15,651 women with singleton pregnancy who delivered at the International Peace Maternity and Child Health Hospital between January 2015 and November 2016. Women were classified in two groups based on their serum 25(OH)D vitamin levels status: VitD sufficient (SUFF) group and VitD insufficient or deficient (INSUFF/DEF). The cut-off point for VitD concentration was 50.00 nmol/L. Comparisons were made between women with normal prepregnancy body weight (BMI 18.5–23.9 kg/m²) and overweight and obese (OWO) women (BMI > 24.0 kg/m²). Early FGR was defined as first-trimester gestational age-adjusted crown-rump length (CRL) in the lowest 20th centile of the population. Multivariate logistic regression was used to evaluate the association between maternal serum 25(OH)D levels and prepregnancy BMI with first trimester CRL and early FGR.

Results

In VitD INSUFF/DEF group, the first trimester CRL was decreased (P = 0.005), and the risk of early FGR was increased by 13% (95% CI 1.04–1.24, P = 0.004) compared to the VitD SUFF group. In OWO group, the first trimester CRL was also significantly decreased (P < 0.0001), and the risk of early FGR was significantly increased by 58% (95% CI 1.40–1.78, P < 0.001) compared with normal weight group. Furthermore, there was a significant combined effect of maternal VitD concentrations and OWO on CRL (P for interaction = 0.02) and the risk of early FGR (P for interaction = 0.07).

Conclusion

Sufficient first trimester serum 25(OH)D concentration was a protective factor for early fetal growth, especially among OWO mothers. Chinese Clinical Trial Registry (Registration number: ChiCTR1900027447 with date of registration on November 13, 2019-retrospectively registered).

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02695-w.

The human yolk sac size reflects involvement in embryonic and fetal growth regulation

INTRODUCTION

The human yolk sac provides the embryo with stem cells, nutrients, and gas exchange. We hypothesized that more maternal resources, reflected in body size and body composition, would condition a a larger yolk sac, ensuring resources for the growing embryo. Thus, we aimed to determine the relation between maternal size in early pregnancy and yolk sac size.

MATERIAL AND METHODS

This subsidiary study was embedded in the multinational World Health Organization fetal growth project that included healthy women with a body mass index of 18-30, reliable information of their regular last menstrual period and singleton pregnancies. Yolk sac diameter, crown-rump length, and maternal height, weight, body mass index, and body composition were assessed before 13 weeks of gestation, and the fetal biometry was repeated during the pregnancy.

RESULTS

Of 140 participants, 122 with a successful yolk sac measurement were entered in the present analysis. Maternal weight was negatively associated with the yolk sac diameter (P = 0.007) and so was maternal height (P = 0.011), fat mass (P = 0.037), and lean body mass (P = 0.018), but not body mass index (P = 0.121). Significant effects were predominantly due to the female embryos and could be traced at 24 weeks of gestation. That is, a small yolk sac : crown-rump length ratio in early pregnancy was associated with a high fetal abdominal circumference (P < 0.001) and estimated fetal weight (P = 0.001).

CONCLUSIONS

The human yolk sac is involved in the regulation of embryonic growth, but contrary to our hypothesis, the yolk sac has a compensatory capacity, being larger when the mothers are smaller; and the effect can be traced on fetal size at 24 weeks of gestation.

Influence of distribution of mother's abdominal body fat on first trimester fetal growth

Objective: Fetal growth in the first trimester is estimated by measuring the crown to rump length of the fetus (CRL). There are no data on the relation between fetal growth and fat distribution in pregnant women. The objective was to investigate the influence of fat distribution in pregnant women on fetal growth in the first trimester of pregnancy.Methods: This was a controlled observation using a random sampling method. Newly registered pregnant women were included in the sample during a 12-18-month period. The study included 400 pregnant women from Bjelovarsko-bilogorska County, Croatia. Participants were divided into three groups according to their pregravid BMI values, normal weight (n = 254), overweight (n = 103), and obese (n = 43). In the 12th week of pregnancy, the CRL was measured by transvaginal ultrasound. The subcutaneous and preperitoneal fat was measured by transabdominal ultrasound, using the Suzuki method. The correlation was tested by the Pearson's coefficient, and a linear regression analysis was performed on the variables with good correlation.Results: In normal weight pregnant women, there is no correlation between the adipose tissue and fetal length, but there is a significant correlation between overweight and obese ones.Conclusion: The distribution of adipose tissue in obese and overweight pregnant women is associated with fetal length in the first trimester of pregnancy, with a stronger correlation between visceral fat and fetal length. The influence of this correlation on the overall fetal growth should be investigated by longitudinal monitoring of these variables during the entire pregnancy.

The effect of obesity on early fetal growth and pregnancy duration: a cohort study

OBJECTIVE

The objective of this study is to investigate the effect of maternal obesity on fetal size in first- and second-trimester pregnancies and to determine duration of pregnancy as estimated by a variety of methods.

METHODS

Between 2006 and 2011, a cohort study included (n = 9055) singleton pregnancies that resulted in live birth at Holbaek Hospital in Denmark. This study recorded first- and second-trimester fetal measurements and maternal anthropometry. Characteristics considered included mother's age, parity, height, body mass index (BMI), smoking habits, and sex of child. The correlation between BMI and duration of pregnancy was analyzed by time-to-event analysis and accounted for medical intervention by censoring while correlation of BMI on fetal size was evaluated by multiple regression analysis.

RESULTS

Adjusting for maternal and fetal characteristics, BMI was associated with prolonged pregnancy duration (0.20-0.22 d per kg/m² (standard error (SE) 0.02)) when using ultrasound and 0.26 d per kg/m² (SE: 0.03) when using last menstrual period. With increasing BMI, fetal biometries in first and second trimester were significantly smaller than expected (0.08 mm per kg/m² when measured by crown rump length (SE 0.02)).

CONCLUSIONS

Maternal BMI is correlated to smaller fetal size in early pregnancy and prolongs duration of pregnancy.

MATERNAL HEIGHT AND PRE-PREGNANCY WEIGHT STATUS ARE ASSOCIATED WITH FETAL GROWTH PATTERNS AND NEWBORN SIZE

The impact of maternal height, pre-pregnancy weight status and gestational weight gain on fetal growth patterns and newborn size was analysed using a dataset of 4261 singleton term births taking place at the Viennese Danube Hospital between 2005 and 2013. Fetal growth patterns were reconstructed from three ultrasound examinations carried out at the 11th/12th, 20th/21th and 32th/33th weeks of gestation. Crown–rump length, biparietal diameter, fronto-occipital diameter, head circumference, abdominal transverse diameter, abdominal anterior–posterior diameter, abdominal circumference and femur length were determined. Birth weight, birth length and head circumference were measured immediately after birth. The vast majority of newborns were of normal weight, i.e. between 2500 and 4000 g. Maternal height showed a just-significant but weak positive association (r=0.03: p=0.039) with crown–rump length at the first trimester and with the majority of fetal parameters at the second trimester (r>0.06; p<0.001) and third trimester (r>0.09; p<0.001). Pre-pregnancy weight status was significantly positively associated with nearly all fetal dimensions at the third trimester (r>0.08; p<0.001). Maternal height (r>0.17; p<0.001) and pre-pregnancy weight status (r>0.13; p<0.001), but also gestational weight gain (r>0.13; p<0.001), were significantly positively associated with newborn size. Some of these associations were quite weak and the statistical significance was mainly due to the large sample size. The association patterns between maternal height and pre-pregnancy weight status with fetal growth patterns (p<0.001), as well as newborn size (p<0.001), were independent of maternal age, nicotine consumption and fetal sex. In general, taller and heavier women gave birth to larger infants. This association between maternal size and fetal growth patterns was detectable from the first trimester onwards.

The effect of maternal body mass index on fetal growth: use of individualized growth assessment and two-level linear modeling

PURPOSE

To determine the effect of maternal body mass index on fetal growth using individualized growth assessment and two-level linear modeling.

METHODS

A retrospective review of biometry in the second and third trimesters from 246 normal, term singleton fetuses was performed. Four to eight biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur diaphysis length (FDL) measurements per fetus were available and used to determine second-trimester growth rates. Expected third-trimester size trajectories were generated from these data and Percent Deviations [%Dev = ((observed - expected)/expected) × 100] were calculated. Two-level linear modeling was used to determine %Dev slopes and the effect of body mass index (BMI) on these slopes. Relationships between individual second- and third-trimester slopes and BMI were evaluated using linear regression.

RESULTS

Linear regression analysis of second-trimester growth indicated no significant relationships between the fetal growth rate and the BMI in the second trimester [R(2) (adj): 0.0% to 1.0% except AC in one subgroup (5.6%)]. Regression analysis did not indicate a significant relationship (adj R(2) : 0%-0.2%) between BMI and third-trimester %Dev slopes for any anatomic parameter. Two-level statistical modeling showed no effect of BMI on BPD, AC, or FDL growth and only a moderate effect on the HC growth in the third trimester.

CONCLUSIONS

Our findings indicate that the maternal BMI does not have an effect on fetal growth in either the second or the third trimester as determined with individualized growth assessment.

Periconception maternal characteristics and embryonic growth trajectories: the Rotterdam Predict study

STUDY QUESTION

Are maternal characteristics and lifestyle factors associated with human embryonic growth trajectories?

SUMMARY ANSWER

Periconception maternal age is associated with increased, and smoking and alcohol use with decreased embryonic growth trajectories, estimated with crown-rump length (CRL) measurements.

WHAT IS KNOWN ALREADY

Fetal weight is associated with health and disease in later life. Maternal characteristics and lifestyle factors affect fetal growth in the second and third trimesters of pregnancy and at birth; however, little is known about the association of these characteristics with first trimester embryonic growth.

STUDY DESIGN, SIZE, DURATION

In a tertiary centre, pregnant women were recruited and enrolled in a prospective periconception cohort study before 8 weeks of gestation. We selected 87 spontaneously conceived singleton pregnancies of women recruited in 2009 and 2010 that ended in non-malformed live births.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We performed weekly three-dimensional ultrasound scans from enrolment up to 13 weeks of gestation. At enrolment, a questionnaire was completed. Embryonic CRL measurements were performed using the V-Scope software in the BARCO I-Space. Associations between maternal characteristics and embryonic growth were assessed using square root transformed CRL as response in linear mixed model analyses, adjusted for potential confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Four hundred and ninety-six scans from 87 pregnancies were included. In the multivariable analysis, maternal age was positively associated with first trimester CRL (difference per maternal year of age 0.024√mm (95% confidence interval (CI) 0.009, 0.040), P = 0.001). At 6 and 12 weeks of gestation, the CRL of an embryo from a 40-year-old mother was estimated 2.0 mm (61%) and 7.2 mm (14%) larger, respectively, compared with an embryo from a 20-year-old mother. Smoking of 10 or more cigarettes per day was negatively associated with CRL (difference -0.211√mm (95% CI -0.416, -0.006), P = 0.04), with embryos that were 0.9 mm (18.7%) and 3.1 mm (5.5%) smaller at 6 and 12 weeks, respectively, compared with non-smokers. Periconception alcohol use was negatively associated with CRL growth rate (difference -0.0025√mm (95% CI -0.0047, -0.0003)/day gestational age, P = 0.022), with embryos that were 0.2 mm (3%) and 1.1 mm (2%) smaller at 6 and 12 weeks, respectively, compared with non-alcohol users. Parity, BMI and moment of initiation of folic acid use were not significantly associated with embryonic CRL.

LIMITATIONS, REASONS FOR CAUTION

Due to the selection of pregnancies in a tertiary centre and the small number of pregnancies, the external validity of the results has to be confirmed using larger sample sizes and other population-based periconception cohort studies.

WIDER IMPLICATIONS OF THE FINDINGS

The association of maternal age and smoking with embryonic growth is in line with previous literature, whereas the association between embryonic growth and alcohol use is a new finding. However, concerning exposure to alcohol, the effect estimate was small and it is questionable whether this is of clinical value. More research is warranted to unravel underlying mechanisms and to assess the implications for preconception and early pregnancy care, such as the development and implementation of effective lifestyle interventions.

STUDY FUNDING/COMPETING INTEREST(S)

The work was funded by the Department of Obstetrics and Gynaecology, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. The authors declare no conflicts of interest.

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.

Influence of fetal and parental factors on intrauterine growth measurements: results of the EDEN mother-child cohort

OBJECTIVE

In small-for-gestational-age neonates, parental and fetal characteristics can be used to distinguish between constitutionally small size and growth restriction, which is associated with a higher risk of morbidity and mortality. The aim of this study was to quantify relationships of parental and fetal characteristics with fetal ultrasound measurements.

METHODS

The EDEN mother-child cohort included 2002 pregnant women with singleton pregnancies attending one of two university hospitals. Data from two routine ultrasound examinations for fetal biometry were recorded, at 20-25 and 30-35 weeks of gestation. Biparietal diameter (BPD), head circumference (HC), femur length (FL), abdominal circumference (AC) and estimated fetal weight (EFW) were studied as a function of prepregnancy maternal body mass index (BMI), maternal height, paternal height, fetal sex and gestational age.

RESULTS

Data were obtained at the first scan from 1833 women and at the second scan from 1752 women. Parental anthropometric characteristics were significantly associated with ultrasound measurements at both scans. Maternal BMI was more strongly associated with AC and EFW, whereas both maternal and paternal height were more strongly associated with FL. An association was also found between fetal sex and all ultrasound measurements other than FL.

CONCLUSION

Maternal and paternal anthropometric characteristics are significantly associated with ultrasound measurements in mid to late pregnancy. These relationships provide support for the use of these characteristics in ultrasound fetal size reference charts.