Carlos Varea

Marriage, age at last birth and fertility in a traditional Moroccan population.

A sample of 842 rural women from Morocco (Amizmiz, Marrakech) was used to examine the relationship between a number of biosocial variables and fertility patterns. For women still in their reproductive years there were significant correlations between family size and womans age, age at marriage and years of marriage. Among women with completed families, those with early age at marriage ceased childbearing about 10 years before reaching menopause, while women who married later continued to bear children until the end of their fertile life.

Hour of birth and birth assistance: From a primate to a medicalized pattern?

Previous studies generally agree that in Homo sapiens births without medical intervention occur mostly at night, although with a less accentuated pattern than in other primate species. The present study has three main objectives: (a) to establish the hourly pattern of births in a modern medicalized population, (b) to explore the association between the hour of birth and maternal and fetal variables and mode of delivery, and (c) to evaluate the risk for medical intervention at different hours of the day.

The pattern of reproductive life in a Berber population of morocco

Reproductive patterns were studied from data collected in 1,450 Berber households in the province of Marrakesh, Morocco in 1984. Women aged 45-49 years had a mean of 8.9 pregnancies to achieve 5.7 living children. Social influences on fertility rates show the importance of tradition, particularly through time-dependent variables such as age at marriage, waiting time to first birth, interbirth intervals, and duration of breastfeeding. Birth control does not appear to affect the tempo of fertility; rather, its main use is to bring the reproductive period to a close. The comparison of two subsamples of women separated by a 25-year interval indicates an actual acceleration of the tempo of fertility by the reduction of waiting time to first birth and of interbirth intervals. The supposed ongoing process of demographic transition is not clearly observed in this population.

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

Abstract 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.

Maternal Characteristics and Temporal Trends in Birth Outcomes: Comparison between Spanish and Migrant Mothers

Low birth weight and preterm babies have been increasing in Spain since 1980, coinciding with important changes in the social and demographic structure of childbearing populations—including the contribution of a 25% of foreign mothers—and with increasing medical intervention in births. This study, based on 5,990,613 births, compares the temporary trends in reproductive patterns and birth outcomes in Spanish and foreign mothers during the period 1996–2009 and evaluates for the years 2007 to 2009 the relative contribution of mothers origin and Caesarean section to birth weight variability. Foreign mothers maintain their own reproductive pattern, whereas negative birth outcomes increase in all groups. Results from logistic regression analysis show that besides late maternity and primiparity also Caesarean section increases the risk for low birth weight. The reduction in Caesarean section rates between 2007 and 2009 might explain the reduction of low birth weight detected. A change of tendency simultaneously appears in most maternal and newborn characteristics, and in the mode of delivery in all ethnic groups since 2008. Coincidence in the timing of the change of trends points to a common factor. We suggest that the current world financial crisis could be this common cause, a hypothesis to be contrasted in future research.

Physiological maturation, reproductive patterns, and female fecundability in a traditional Moroccan population (Amizmiz, Marrakech)

The interaction between age at menarche, adolescent motherhood, and subfecundity were evaluated in 496 Moroccan women 25–54 years of age from the province of Marrakech. Since this population is characterized by later sexual maturation and early marriage, significantly increased subfecundity, measured by the waiting time to first live birth and the incidence of fetal loss, was expected. Menstrual age was defined as the difference between age at marriage and age at menarche. Social access to reproduction was conditioned by age at menarche: early maturers married at a younger age, while late maturers had a significantly shorter menstrual age despite the fact that married at a significantly older age. Although there was a tendency for late maturers to have longer waiting times and more fetal loss, there were no significant differences for either variable according to menarcheal age. Women with a shorter menstrual age became pregnant within the first year after marriage significantly less frequently than women with a greater menstrual age, but did not experience a greater occurrence of fetal loss during their reproductive life. The results indirectly support the hypothesis that the regularity of ovarian function is similar among populations independent of the timing of menarche.

Revisiting the daily human birth pattern: time of delivery at Casa de Maternidad in Madrid (1887-1892).

Among the ancestral characteristics of the primate group to which Homo sapiens belongs we find a pattern of daytime physical activity, but one notable exception is birthing which usually begins with night‐time labor. In populations with a moderate or high level of medicalized labor, there is evidence that the medical preferences interfere with the underlying biological mechanism for the circadian pattern of human birth.

New birthweight charts by 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.

Pregnancy outcome and delivery in Spanish and migrant women: an ecological approach

Abstract For most of our history as a species, maternal constraint was the main environmental factor affecting biological status at birth. However, the great increase in medical intervention in the20th Century coincided first with an extraordinary reduction in perinatal mortality and later with an increase in preterm and low birth-weight babies. Herein, we analyze these temporary trends in neonate biology in Spain, according to early viability (1980-2010) and ethnic variability (1996-2010). The aim of this study is to evaluate the interaction between maternal and medical environmental constraints affecting the biology of birth and to understand the observed ethnic differences and secular trends. All single births in Spain between 1980 and 2010 are included. Following descriptive analysis, logistic regression analysis was applied to evaluate the effect of secular trends, mode of delivery and mother’s origin on birth outcome after adjustment for other maternal bio-cultural factors. Results highlighted that mean birth weight decreased and prematurity increased in still births, live births and deaths before one day. In regard to ethnic differences, while there were no secular trends in weight by gestational age in the Spanish newborns, there was an increase among the newborns of foreign mothers. Spanish mothers experienced an increasing and higher frequency of low birth weight, while foreigners had an increasing and higher frequency of prematurity. Both groups, however, shared temporal reduction in gestational age, and although this was less marked in foreigners, it suggests a common trend related to medical care and increasing obstetric interventions

The impact of delayed maternity on foetal growth in Spain: An assessment by population attributable fraction

BACKGROUND Delayed childbearing is considered a risk factor for maternal-foetal health. As in other higher-income countries, in Spain age at maternity has steadily increased during the last two decades. AIM To quantify the impact of the delay in the age at maternity on small for gestational age (SGA) categories of <3rd, 3rd-5th and 5th-10th percentiles. METHODS 2,672,350 singleton live births born to Spanish mothers in 2007-2015 were analysed. Adjusted relative risk was calculated to estimate the adjusted partial population attributable fractions (PAFp) for mothers aged 35-39 and ≥40 years for each category of SGA considering the interaction between age at maternity and parity. FINDINGS Primipara 35-39 years old mothers have the highest PAFp in the three categories of SGA, with the maximum value for SGA <3rd percentile (2.57%, 95% CI 2.25, 2.88). PAFp for both primipara and multipara ≥40 years old mothers were less than 1%. PAFp for primipara older mothers increased significantly in 2007-2015 for the three categories of SGA, more clearly among those aged 35-39 years. The contribution of multipara mothers of both age groups did not increase significantly during the period. CONCLUSION Delayed maternity is a significant adjusted risk factor for SGA, contributing to the increase of its prevalence. However, results also suggest a limited clinical impact of delayed maternity on foetal growth. Positive changes in maternal profile associated with the shift in maternal age might contribute to explain the limited impact of mothers aged 35 years and older on negative birth outcome in Spain.