Differences in birthweight curves between newborns of immigrant mothers vs. infants born in their corresponding native countries: systematic overview

Effect of maternal serum albumin level on birthweight and gestational age: an analysis of 39200 singleton newborns

Background

Serum albumin plays a pivotal role in regulating plasma oncotic pressure and modulating fluid distribution among various body compartments. Previous research examining the association between maternal serum albumin levels and fetal growth yielded limited and inconclusive findings. Therefore, the specific influence of serum albumin on fetal growth remains poorly understood and warrants further investigation.

Methods

A retrospective study involved 39200 women who had a singleton live birth at a tertiary-care academic medical center during the period from January 2017 to December 2020. Women were categorized into four groups according to the quartile of albumin concentration during early pregnancy: Q1 group, ≤41.0 g/L; Q2 group, 41.1-42.6 g/L; Q3 group, 42.7-44.3 g/L and Q4 group, >44.3 g/L. The main outcome measures were mid-term estimated fetal weight, birthweight and gestational age. Multivariate linear and logistic regression analysis were performed to detect the independent effect of maternal serum albumin level on fetal growth after adjusting for important confounding variables.

Results

In the crude analysis, a significant inverse correlation was found between early pregnancy maternal serum albumin levels and fetal growth status, including mid-term ultrasound measurements, mid-term estimated fetal weight, birthweight, and gestational age. After adjustment for a number of confounding factors, mid-term estimated fetal weight, birthweight, and birth height decreased significantly with increasing albumin levels. Compared to the Q2 group, the Q4 group had higher rates of preterm birth (aOR, 1.16; 95% CI, 1.01-1.34), small-for-gestational-age (aOR, 1.27; 95% CI, 1.11-1.45) and low birthweight (aOR, 1.41; 95% CI, 1.18-1.69), and lower rate of large-for-gestational-age (aOR, 0.85; 95% CI, 0.78-0.94). Moreover, to achieve the optimal neonatal outcome, women with higher early pregnancy albumin levels required a greater reduction in albumin levels in later pregnancy stages.

Conclusions

A higher maternal serum albumin level during early pregnancy was associated with poor fetal growth, with the detrimental effects becoming apparent as early as the mid-gestation period. These findings provided vital information for clinicians to predict fetal growth status and identify cases with a high risk of adverse neonatal outcomes early on.

Advanced trophectoderm quality increases the risk of a large for gestational age baby in single frozen-thawed blastocyst transfer cycles

STUDY QUESTION

Does trophectoderm (TE) quality affect birthweight after single frozen-thawed blastocyst transfer?

SUMMARY ANSWER

Transfer of single blastocyst with advanced TE quality was associated with higher birthweight and increased risk of a large for gestational age (LGA) baby.

WHAT IS KNOWN ALREADY

Transfer of blastocysts with advanced TE quality results in higher ongoing pregnancy rates and a lower miscarriage risk. However, data on the relationship between TE quality and birthweight are still lacking.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study at a tertiary-care academic medical center included 1548 singleton babies born from single frozen-thawed blastocyst transfer from January 2011 to June 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Babies were grouped into four groups according to embryo expansion (Stages 3, 4, 5 and 6), three groups according to inner cell mass (ICM) quality (A, B and C), and three groups according to TE quality (A, B and C). Main outcomes included absolute birthweight, Z-scores adjusted for gestational age and gender, and adverse neonatal outcomes. Multivariable linear and logistic regression analyses were performed to investigate the association of neonatal outcomes with expansion stage, ICM quality and TE quality.

MAIN RESULTS AND THE ROLE OF CHANCE

As TE quality decreased, birthweight (3468.10 ± 471.52, 3357.69 ± 522.06, and 3288.79 ± 501.90 for A, B and C, respectively, P = 0.002), Z-scores (0.59 ± 1.07, 0.42 ± 1.04, and 0.27 ± 1.06 for A, B and C, respectively, P = 0.002) and incidence of LGA (28.9%, 19.7% and 17.4% for A, B and C, respectively, P = 0.027) decreased correspondingly. After adjusting for confounders, compared with the Grade A group, blastocysts with TE Grade B (standardized coefficients (β): -127.97 g, 95% CI: -234.46 to -21.47, P = 0.019) and blastocysts with TE grade C (β: -200.27 g, 95% CI: -320.69 to -79.86, P = 0.001) resulted in offspring with lower birthweight. Blastocysts with TE grade C brought babies with lower Z-scores than TE Grade A (β: -0.35, 95% CI: -0.59 to -0.10, P = 0.005). Also, embryos with TE Grade B (adjusted odds ratio (aOR):0.91, 95% CI: 0.84 to 0.99, P = 0.033) and embryos with TE Grade C (aOR : 0.89, 95% CI: 0.81 to 0.98, P = 0.016) had lower chance of leading to a LGA baby than those with TE Grade A. No association between neonatal outcomes with embryo expansion stage and ICM was observed (all P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

The retrospective design, lack of controlling for several unknown confounders, and inter-observer variation limited this study.

WIDER IMPLICATIONS OF THE FINDINGS

The study extends our knowledge of the down-stream effect of TE quality on newborn birthweight and the risk of LGA.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by National Key R&D Program of China (2018YFC1003000), National Natural Science Foundation of China (81771533 to Y.P.K. and 31200825 to L.S.) and Innovative Research Team of High-level Local Universities in Shanghai (SSMU-ZLCX20180401), Shanghai Sailing Program(21YF1423200) and the Fundamental research program funding of Ninth People's Hospital affiliated to Shanghai Jiao Tong university School of Medicine (JYZZ117). The authors declare no conflict of interest in this present study.

TRIAL REGISTRATION NUMBER

N/A.

An updated reference for age-sex-specific birth weight percentiles stratified for ethnicity based on data from all live birth infants between 2005 and 2014 in Alberta, Canada

OBJECTIVE

This study aims to update the current reference for sex-specific birth weight percentiles by gestational age, overall and for specific ethnic groups, based on data from all singleton live-birth deliveries from 2005 to 2014 in Alberta, Canada.

METHODS

Infant and maternal information were captured in the Alberta Vital Statistics-Births Database for 473,115 singleton infants born to 311,800 women between January 1, 2005 and December 31, 2014. Within each sex, and each sex-ethnic group, birth weights were modelled by gestational age using generalized additive models and natural cubic splines. Crude and corrected estimates for birth weight percentiles including cut-off values for large for gestational age (LGA) and small for gestational age (SGA) were calculated by sex and sex-ethnic group, and gestational age for singleton live births.

RESULTS

LGA and SGA cut-offs were lower for females than for males for all gestational ages. The SGA and LGA percentiles were greater for both male and female very preterm infants in Alberta compared to previous national references. Ethnicity-specific LGA and SGA cut-offs for term Chinese and preterm and at-term South Asian infants were consistently lower than those for both the general population in Alberta and the previous national reference. South Asian infants had lower birth weights at almost all gestational ages compared with the other groups.

CONCLUSION

The updated birth weight percentiles presented in this study highlight the differences in SGA and LGA cut-offs among infants from South Asian, Chinese, and the general population, which may be important for clinical perinatal care.

[Pregnant Women with Gestational Diabetes in Berlin - An Analysis of Perinatal Data Especially Regarding Immigration Background]

To date there has not been a systematic analysis of pregnant patients with an immigrant background and gestational diabetes in Germany, even though the number of these patients has been rising continuously since the 1980s.

METHODS

The case number estimate for this prospective study targeted 160 patients with gestational diabetes with and without an immigrant background. A questionnaire on socio-economic status, immigrant background, acculturation, and food intake was developed. The birth parameters and pre- and postpartum parameters were regularly documented.

RESULTS

In our study we included 198 patients with gestational diabetes, consisting of 110 patients with an immigrant background and 88 patients without an immigrant background. The number of labor inductions for the suspected diagnosis of fetal macrosomia was almost the same in both groups (immigrant background 3.6% vs. without immigrant background 4.6%, p=1.0; OR 1.73; 95% CI; 0.79-3.89, p=0.17). The study patients with an immigrant background were more likely to give birth spontaneously than via cesarean section or vaginal-operative birth. The perinatal outcome of children from our study patients with and without an immigrant background were similar.

CONCLUSION

We show that regardless of their immigrant background gestational diabetes patients have similar and homogeneous patient-centered care at our clinic.

Birth-weight differences at term are explained by placental dysfunction and not by maternal ethnicity. Study in newborns of first generation immigrants

Objective: The aim of the study was to investigate the influence of ethnicity and cerebroplacental ratio (CPR) on the birth weight (BW) of first generation Indo-Pakistan immigrants' newborns.Methods: This was a retrospective study in a mixed population of 620 term Caucasian and Indo-Pakistan pregnancies, evaluated in two reference hospitals of Spain and Italy. All fetuses underwent a scan and Doppler examination within two weeks of delivery. The influence of fetal gender, ethnicity, GA at delivery, CPR, maternal age, height, weight and parity on BW was evaluated by multivariable regression analysis.Results: Newborns of first generation Indo-Pakistan immigrants were smaller than local Caucasian newborns (mean BW mean= 3048 ± 435 g versus 3269 ± 437 g, p < .001). Multivariable regression analysis demonstrated that all studied parameters, but maternal age and ethnicity, were significantly associated with BW. The most important were GA at delivery (partial R² = 0.175, p < .001), CPR (partial R² = 0.032, p < .001), and fetal gender (partial R² = 0,029, p < .001).Conclusions: The propensity to a lower BW, explained by placental dysfunction but not by maternal ethnicity is transmitted to newborns of first generation immigrants. Whatever are the factors implied they persist in the new residential setting.

Effect of birth weight and nutritional status on transverse maxillary growth: Implications for maternal and infant health

We analyzed the association between birthweight, nutritional status and transverse maxillary growth in 7- to 9-year-old schoolchildren. We undertook a cross-sectional survey nested in a population-based cohort study of 158 schoolchildren. The participants lived in the urban area of a small town within the Western Brazilian Amazon. The outcome was represented by the upper intermolar distance given in millimeters (mm), as an indicator of the degree of maxillary bone growth in its transverse dimension. The exposures were sex, birthweight, the bottle-feeding pattern operationalized by a scale corresponding to the age of introduction of the bottle and Body Mass Index-for-age z-score (BAZ) at 4 to 6 ys. Path analysis was employed to estimate standardized direct, indirect and total effects of exposures on the outcome using structural equations model (SEM) supported by Mplus 7 program. The values of standardized coefficients (SC) showed significant direct positive effects of sex (SC = 0.203; p = 0.006), birth weight (SC = 0.155; p = 0.030) and BAZ (SC = 0.165; p = 0.014) on transverse maxillary growth. The indirect effects (SC = 0.057; p = 0.012) and the total effect (SC = 0.261; p<0.001) of sex on the outcome were statistically significant. The indirect effects of birth weight on the outcome were not significant (SC = 0.018; p = 0.488), however, the total effect was significant (SC = 0.174; p = 0.011). In conclusion, sex, birthweight, bottle beginning age and BAZ showed association with the transverse growth of the maxillary bone. In addition to contributing to an adequate birth weight of the child, policies and programs that favor prenatal care and conditions to guarantee a full-term birth can positively affect transverse growth of the maxilla. From a Public Health Surveillance point of view, children with reduced birthweight, inadequate breastfeeding pattern and nutritional deficit for age may be more likely to develop atrophy of the jaws which, depending on the severity, may result in malocclusion with an important impact on quality of life.

Scoping Review on Maternal Health among Immigrant and Refugee Women in Canada: Prenatal, Intrapartum, and Postnatal Care

The last fifteen years have seen a dramatic increase in both the childbearing age and diversity of women migrating to Canada. The resulting health impact underscores the need to explore access to health services and the related maternal health outcome. This article reports on the results of a scoping review focused on migrant maternal health within the context of accessible and effective health services during pregnancy and following delivery. One hundred and twenty-six articles published between 2000 and 2016 that met our inclusion criteria and related to this group of migrant women, with pregnancy/motherhood status, who were living in Canada, were identified. This review points at complex health outcomes among immigrant and refugee women that occur within the compelling gaps in our knowledge of maternal health during all phases of maternity. Throughout the prenatal, intrapartum, and postnatal periods of maternity, barriers to accessing healthcare services were found to disadvantage immigrant and refugee women putting them at risk for challenging maternal health outcomes. Interactions between the uptake of health information and factors related to the process of immigrant settlement were identified as major barriers. Availability of appropriate services in a country that provides universal healthcare is discussed.

Birth-weight charts and immigrant populations: A critical review

There is an increasing body of literature focusing on differences in newborn size between different population subgroups defined by racial, ethnic, and immigration status. The interpretation of these differences as pathological or as merely reflecting normal variability is not straightforward and may have consequences for the provision of obstetric and neonatal care to minority populations. In this review, we critically assess some methodological issues affecting the assessment of newborn size and their potential implications for minority populations. In particular, we discuss the pros and cons of different types of newborn birth-weight (BW) charts (i.e., single local population-based references, minority-specific references, and a single international standard) to determine abnormal newborn size, with emphasis on immigrant populations. We conclude that size alone is not enough to inform clinical decisions and that all newborn size charts should be used as screening tools, not as diagnostic tools. Parental minority status may be regarded as a marker and used to further inquire about individual risk factors, particularly among immigrants who may not have a complete medical history in the new country. Finally, we outline areas for further research and recommendations for clinical practice.

Immigrants from conflict-zone countries: an observational comparison study of obstetric outcomes in a low-risk maternity ward in Norway

Background

Immigrants have higher risks for some adverse obstetric outcomes. Furthermore, refugees are reported to be the most vulnerable group. This study compared obstetric outcomes between immigrant women originating from conflict-zone countries and ethnic Norwegians who gave birth in a low-risk setting.

Methods

This was a population-based study linking the Medical Birth Registry of Norway to Statistics Norway. The study included the first registered birth during the study period of women from Somalia (n = 278), Iraq (n = 166), Afghanistan (n = 71), and Kosovo (n = 67) and ethnic Norwegians (n = 6826) at Baerum Hospital from 2006–2010. Background characteristics and obstetric outcomes of each immigrant group were compared with ethnic Norwegians with respect to proportions and risks calculated by logistic regression models.

Results

In total, 7408 women and their births were analyzed. Women from Somalia were most at risk for adverse obstetric outcomes. Compared with ethnic Norwegians, they had increased odds ratios (OR) for emergency cesarean section (OR 1.81, CI 1.17–2.80), postterm birth (OR 1.93, CI 1.29–2.90), meconium-stained liquor (OR 2.39, CI 1.76–3.25), and having a small-for-gestational-age infant (OR 3.97, CI 2.73–5.77). They had a reduced OR for having epidural analgesia (OR 0.40, CI 0.28–0.56) and a large-for-gestational-age infant (OR 0.32, CI 0.16–0.64). Women from Iraq and Afghanistan had increased risk of having a small-for-gestational-age infant with OR of 2.21 (CI 1.36–3.60) and 2.77 (CI 1.42–5.39), respectively. Iraqi women also had reduced odds ratio of having a large-for-gestational-age infant (OR 0.35, CI 0.15–0.83). Women from Kosovo did not differ from ethnic Norwegians in any of the outcomes we tested.

Conclusions

Even in our low-risk maternity ward, women originating from Somalia were at the greatest risk for adverse obstetric outcomes in the compared groups. We could not find the same risk among the other immigrant women, also originating from conflict-zone countries. Several factors may influence these findings, and this study suggests that immigrant women from Somalia need more targeted care during pregnancy and childbirth.

Influence of paternal and maternal ethnicity and ethnic enclaves on newborn weight

BACKGROUND

The association between maternal ethnicity and newborn weight is understood. Less is known about the additional influence of paternal ethnicity and neighbourhood ethnic composition.

METHODS

We studied 692 301 singleton live births of parents of Canadian, Bangladeshi, Sri Lankan, Pakistani, Indian, Filipino, Vietnamese, Korean, Hong Kong or Chinese birthplace. We used multivariable regression to calculate mean (95% CI) birthweight differences between infants of two Canadian-origin parents and (1) foreign-born mother and Canadian-born father, (2) Canadian-born mother and foreign-born father or (3) two foreign-born parents from the same country. We also stratified by high versus low same-ethnic concentration of the parent's residence. We adjusted for gestational age at birth, maternal age, parity, marital status and income quintile.

RESULTS

Compared with male and female infants of two Canadian-born parents, those of same-country foreign-born parents weighed 6.2% (-218 g, 95% CI -214 g to -223 g) and 5.6% (-192 g, 95% CI -187 g to -196 g) less, respectively. The largest mean weight difference was among male (8.4% (-297 g, 95% CI -276 g to -319 g)) and female (8.2% (-279 g, 95% CI -262 g to -296 g)) infants of two Bangladeshi parents. Infants of a foreign-born mother and Canadian-born father had weights closest to those of two Canadian-born parents. Residing in an area of high (vs low) same-ethnic concentration was associated with lower birthweight among infants of mixed union couples, but not among those of parents originating from the same country.

CONCLUSIONS

Paternal and maternal ethnic origin influence newborn weight, which is modified by settlement in a high same-ethnic concentration area only among parents of mixed union.