Calidad de los datos utilizados para el cálculo de indicadores de salud reproductiva y perinatal en población autóctona e inmigrante

Missing girls among deliveries from Indian and Chinese mothers in Spain 2007-2015

Deliveries from Indian and Chinese mothers present a higher than expected male:female ratio in their own countries, in northern Europe, EEUU and Canada. No studies have been carried out in southern European countries. We explored whether the high male-to-female ratio common in Indian and Chinese communities, also exists among families from those regions who live in Spain. For that purpose we designed a cross-sectional population-based study containing data on 3,133,908 singleton live births registered in the Spanish Vital Statistics Registry during the period 2007-2015. The ratio of male:female births by area of origin was calculated using binary intercept-only logistic regression models without reference category for the whole sample of births and taking into account a possible effect modification of birth order and sex of the previous males. Interaction effects of sociodemographic mothers' and fathers' characteristics was also assesed. In Spain, the ratio male:female is higher than expected for Indian-born mothers, especially for deliveries from mothers with no previous male births and, to a lesser extent, for Chinese-born women, specifically for third or higher order births and slightly influenced by the sex of the previous births. Therefore, the increased sex male:female ratio observed in other countries among Indian and Chinese mothers is also observed in Spain. This reinforces the notion that culture and values of the country of origin are more influential than the country of residence.

New birthweight charts according to parity and type of delivery for the Spanish population

OBJECTIVE

Birthweight by gestational age charts enable fetal growth to be evaluated in a specific population. Given that maternal profile and obstetric practice have undergone a remarkable change over the past few decades in Spain, this paper presents new Spanish reference percentile charts stratified by gender, parity and type of delivery. They have been prepared with data from the 2010-2014 period of the Spanish Birth Statistics Bulletin.

METHODS

Reference charts have been prepared using the LMS method, corresponding to 1,428,769 single, live births born to Spanish mothers. Percentile values and mean birth weight are compared among newborns according to gender, parity and type of delivery.

RESULTS

Newborns to primiparous mothers show significantly lower birthweight than those born to multiparous mothers (p<0.036). Caesarean section was associated with a substantially lower birthweight in preterm births (p<0.048), and with a substantially higher birthweight for full-term deliveries (p<0.030). Prevalence of small for gestational age is significantly higher in newborns born by Caesarean section, both in primiparous (p<0.08) and multiparous mothers (p<0.027) and, conversely, the prevalence of large for gestational age among full-term births is again greater both in primiparous (p<0.035) and in multiparous mothers (p<0.007).

CONCLUSIONS

Results support the consideration of establishing parity and type of delivery-specific birthweight references. These new charts enable a better evaluation of the impact of the demographic, reproductive and obstetric trends currently in Spain on fetal growth.

Is the economic crisis affecting birth outcome in Spain? Evaluation of temporal trend in underweight at birth (2003-2012)

BACKGROUND

There is growing evidence of the impact of the current European economic crisis on health. In Spain, since 2008, there have been increasing levels of impoverishment and inequality, and important cuts in social services.

AIM

The objective is to evaluate the impact of the economic crisis on underweight at birth in Spain.

METHOD

Trends in underweight at birth were examined between 2003 and 2012. Underweight at birth is defined as a singleton, term neonatal weight lesser than -2 SD from the median weight at birth for each sex estimated by the WHO Standard Growth Reference. Using data from the Statistical Bulletin of Childbirth, 2 933 485 live births born to Spanish mothers have been analysed. Descriptive analysis, seasonal decomposition analysis and crude and adjusted logistic regression including individual maternal and foetal variables as well as exogenous economic indicators have been performed.

RESULTS AND CONCLUSIONS

Results demonstrate a significant increase in the prevalence of underweight at birth from 2008. All maternal-foetal categories were affected, including those showing the lowest prevalence before the crisis. In the full adjusted logistic regression, year-on-year GDP per capita remains predictive on underweight at birth risk. Previous trends in maternal socio-demographic profiles and a direct impact of the crisis are discussed to explain the trends described.

Inequalities in perinatal mortality rates among immigrant and native population in Spain, 2005-2008

We compared perinatal mortality rates (PMRs) and the risk from certain causes among immigrant and native population in the Valencian Community (Spain). Using data from the Perinatal Mortality Registry, crude and age standardized mortality ratios were obtained in the different groups of mothers. Mortality rate ratios were calculated to compare the causes of death resulting from prematurity, congenital anomalies, infectious diseases and Sudden Infant Death Syndrome between Spanish and foreign women. PMRs were higher among all the immigrant groups compared with the native population, with a statistical significance in Eastern European and sub-Saharan mothers. Neonatal mortality rates in North African and Latin American mothers were similar to those of native women. Babies of immigrant mothers were at a significant higher risk of dying from late infectious diseases and from causes resulting from being premature. More research is needed on the risk factors which contribute to generating differences in our setting.

TESTING THE EFFECT OF THE EPIDEMIOLOGIC PARADOX: BIRTH WEIGHT OF NEWBORNS OF IMMIGRANT AND NON-IMMIGRANT MOTHERS IN THE REGION OF VALENCIA, SPAIN

The epidemiological paradox and ‘healthy migrant effect’ refer to the favourable health outcomes in unprivileged groups under unfavourable socioeconomic conditions. Weight at birth is associated with the epidemiological paradox. However, differences in fertility structure (mainly mother's age and first maternity) might be the cause of the difference in weight at birth between children of immigrant and non-immigrant mothers. This paper aims to analyse the impact of the epidemiologic paradox by distinguishing between the factors related to fertility structure, in addition to other socio-cultural factors. The importance of fertility structure as the cause of weight-at-birth differences of the newborns of immigrant and non-immigrant women, and between those of subgroups of immigrant mothers, is tested. Based on data from birth registries for the period 1998–2009, a variance analysis was performed for Spanish mothers and for those of five major immigrant subgroups living in the region of Valencia, Spain, which experienced significant migrant inflows within a short period of time. A Scheffé test between pairs of nationalities was carried out. Finally, linear regression models were built. The results suggest that the most relevant factors are those related to fertility structure, and that consequently the epidemiological paradox does not apply for immigrant mothers as a whole, although Bolivian immigrant offspring may be an exception. This unexpected result requires further research to test to what extent this is due to the special adaptation of multigenerational high-altitude populations in pregnancy. The factors associated with fertility structure must be controlled when trying to relate birth weight differences between ethnic groups to socioeconomic factors.

Adverse birth outcomes in the vicinity of industrial installations in Spain 2004-2008

Industrial activity is one of the main sources of ambient pollution in developed countries. However, research analyzing its effect on birth outcomes is inconclusive. We analyzed the association between proximity of mother's municipality of residence to industries from 24 different activity groups and risk of very (VPTB) and moderate (MPTB) preterm birth, very (VLBW) and moderate (MLBW) low birth weight, and small for gestational age (SGA) in Spain, 2004-2008. An ecological study was defined, and a "near vs. far" analysis (3.5 km threshold) was carried out using Hierarchical Bayesian models implemented via Integrated Nested Laplace Approximation. VPTB risk was higher for mothers living near pharmaceutical companies. Proximity to galvanization and hazardous waste management industries increased the risk of MPTB. Risk of VLBW was higher for mothers residing near pharmaceutical and non-hazardous or animal waste management industries. For MLBW many associations were found, being notable the proximity to mining, biocides and animal waste management plants. The strongest association for SGA was found with proximity to management animal waste plants. These results highlight the importance of further research on the relationship between proximity to industrial sites and the occurrence of adverse birth outcomes especially for the case of pharmaceutical and animal waste management activities.

[Reproductive and perinatal health indicators in immigrant and Spanish-born women in Catalonia and Valencia (2005-2006)]

OBJECTIVES

To determine the prevalence of teenage maternity, preterm birth and low birth weight in Spanish and immigrant mothers from Latin America, eastern Europe, Maghreb and sub-Saharan Africa resident in Catalonia and Valencia from 2005 and 2006.

METHODS

Using data from congenital metabolic disorders registers in both regions, proportions and 95% confidence intervals were obtained for the following: 1) mothers aged less than 20 years; 2) preterm (<37 weeks) and very preterm (<32 weeks) births; and 3) low birth weight (<2500g) and very low birth weight (<1500g) neonates. The calculations were performed for mothers from each of the geographical areas of origin (Spain, Latin America, Eastern Europe, Maghreb and Sub-Sahara). These proportions were compared in Spanish-born and immigrant women and the significance of differences was assessed using chi-squared tests.

RESULTS

The prevalence of teenage mothers was between three and five times higher in immigrants than in Spanish women, the highest rate being found in women from eastern Europe. Preterm births, very preterm births and very low birth weight were more frequent in eastern European women than in Spanish women. The prevalence of prematurity and very low birth weight was higher in sub-Saharan mothers than in Spanish women.

CONCLUSIONS

The number of births in teenage mothers was higher in immigrant mothers from all origins than in Spanish women. The highest rates of low birth weight and preterm births were found in women from eastern Europe and sub-Saharan Africa.