PubMed Health⌕ Search

Biomedical subjects

Olga Basso

Publications and source records attributed to Olga Basso.

At least 19 recordsLinked to original sources
PubMed2007

Infertility, infertility treatment and twinning: the Danish National Birth Cohort.

BACKGROUND: We have previously observed that an increasing time to pregnancy (TTP) is associated with a reduced frequency of twin deliveries in couples not receiving infertility treatment. By using updated information, we assessed the frequencies of dizygotic (DZ) and monozygotic (MZ) twin deliveries as a function of infertility (TTP > 12 months), as well as infertility treatment. METHODS: From the Danish National Birth Cohort (1997-2003), we identified 51 730 fertile couples with TTP 12 months and 5163 infertile couples who conceived after treatment. Information on zygosity, available for part of the cohort (1997-2000), was based on standardized questions on the similarities between the twins at the age of 3-5 years. RESULTS: Compared with fertile couples, the frequency of DZ twin deliveries was lower for infertile couples conceiving naturally (odds ratio 0.4, 95% confidence interval 0.2-0.7) and was much higher for infertile couples conceiving after treatment (17.3, 14.4-20.7). The frequency of DZ twin deliveries decreased with TTP in untreated couples, whereas the frequency of MZ twin deliveries remained constant. CONCLUSIONS: The frequency of DZ twin deliveries decreased with TTP and substantially increased with infertility treatment, whereas MZ twin deliveries remained substantially unchanged.

Adult↗
PubMed2006

Trends in fetal and infant survival following preeclampsia.

CONTEXT: Management of preeclampsia often culminates in induced delivery of a very preterm infant. While early termination protects the fetus from an intrauterine death, the newborn then faces increased risks associated with preterm delivery. This practice has increased in recent decades, but its net effect on fetal and infant survival has not been assessed. OBJECTIVE: To assess the effect on fetal and infant survival of increased rates of early delivery of preeclamptic pregnancies. DESIGN, SETTING, AND PARTICIPANTS: Population-based observational longitudinal study using registry data from 804 448 singleton first-born infants with Norwegian-born mothers and registered in the Medical Birth Registry of Norway between 1967 and 2003. MAIN OUTCOME MEASURES: Odds ratio (OR) of fetal and early childhood death in relation to preeclampsia. RESULTS: Among preeclamptic pregnancies, inductions before 37 weeks increased from 8% in 1967-1978 to nearly 20% in 1991-2003. During this period, the adjusted OR for stillbirth decreased from 4.2 (95% confidence interval [CI], 3.8-4.7) to 1.3 (95% CI, 1.1-1.7) for preeclamptic compared with nonpreeclamptic pregnancies. During the same period, the OR for neonatal death after preeclamptic pregnancy remained relatively stable (1.7 in 1967-1978 vs 2.0 in 1991-2003). Later infant and childhood mortality also showed little change. CONCLUSIONS: Fetal survival in preeclamptic pregnancies has vastly improved over the past 35 years in Norway, presumably because of more aggressive clinical management. However, the relative risk of neonatal death following a preeclamptic pregnancy has not changed over time.

Cesarean Section↗
PubMed2006

Infertility, infertility treatment, and congenital malformations: Danish national birth cohort.

OBJECTIVES: To examine whether infertile couples (with a time to pregnancy of > 12 months), who conceive naturally or after treatment, give birth to children with an increased prevalence of congenital malformations. DESIGN: Longitudinal study. SETTING: Danish national birth cohort. PARTICIPANTS: Three groups of liveborn children and their mothers: 50,897 singletons and 1366 twins born of fertile couples (time to pregnancy < or = 12 months), 5764 singletons and 100 twins born of infertile couples who conceived naturally (time to pregnancy > 12 months), and 4588 singletons and 1690 twins born after infertility treatment. MAIN OUTCOME MEASURES: Prevalence of congenital malformations determined from hospital discharge diagnoses. RESULTS: Compared with singletons born of fertile couples, singletons born of infertile couples who conceived naturally or after treatment had a higher prevalence of congenital malformations-hazard ratios 1.20 (95% confidence interval 1.07 to 1.35) and 1.39 (1.23 to 1.57). The overall prevalence of congenital malformations increased with increasing time to pregnancy. When the analysis was restricted to singletons born of infertile couples, babies born after treatment had an increased prevalence of genital organ malformations (hazard ratio 2.32, 1.24 to 4.35) compared with babies conceived naturally. No significant differences existed in the overall prevalence of congenital malformations among twins. CONCLUSIONS: Hormonal treatment for infertility may be related to the occurrence of malformations of genital organs, but our results suggest that the reported increased prevalence of congenital malformations seen in singletons born after assisted reproductive technology is partly due to the underlying infertility or its determinants. The association between untreated infertility and congenital malformations warrants further examination.

Cohort Studies↗
PubMed2006

Birth weight and mortality: causality or confounding?

The association between birth weight and mortality is among the strongest seen in epidemiology. While preterm delivery causes both small babies and high mortality, it does not explain this association. Fetal growth restriction has also been proposed, although its features are unclear because it lacks a definition independent of weight. If, as some postulate, birth weight is not itself on the causal path to mortality, its relation with mortality would have to be explained by confounding factors that decrease birth weight and increase mortality. In this paper, the authors explore the characteristics such confounders would require in order to achieve the observed association between birth weight and mortality. Through a simple simulation, they found that the observed steep gradient of risk for small babies at term can be produced by a rare condition or conditions (with a total prevalence of 0.5%) having profound effects on both fetal growth (-1.7 standard deviations) and mortality (relative risk = 160). Candidate conditions might include malformations, fetal or placental aneuploidy, infections, or imprinting disorders. If such rare factors underlie the association of birth weight with mortality, it would have broad implications for the study of fetal growth restriction and birth weight, and for the prevention of infant mortality.

Birth Weight↗
PubMed2006

Paternal age and delivery before 32 weeks.

BACKGROUND: Advanced paternal age has been linked to early preterm delivery (before 32 weeks). METHODS: We analyzed live births from white, non-Hispanic primiparas recorded in U.S. birth certificates from 1995 to 2000 (excluding California). We examined 2,509,012 pregnancies of married women 20 to 34 years old, excluding unmarried women due to the high fraction of missing data on father's age. We defined the outcome according to the clinical estimate of gestation after excluding unlikely birth weights, because the estimate based on last menstrual period is particularly prone to errors at early gestations. RESULTS: Older paternal age was not associated with increased risk of early preterm delivery. The highest estimated odds ratio among fathers 50 years or older was 1.3 (95% confidence interval = 0.6-2.8) among women 20 to 24 years old. CONCLUSIONS: These U.S. data do not support an association between advanced paternal age and delivery before 32 weeks.

Adult↗
PubMed2005

Paternal age and congenital malformations.

BACKGROUND: Spontaneous mutations in germ cells increase with male age, but an association between paternal age and congenital malformations is not well established. We conducted a population-based cohort study to estimate this association. METHODS: A study population of couples and their firstborn children were identified in the Danish Fertility Database between 1980 and 1996 (n = 71937). Diagnoses of congenital malformations in children were obtained by linkage to the nationwide hospital register (1980-1999). RESULTS: Overall, there were no differences in the prevalence of malformations as a function of paternal age. However, the prevalence of malformations of extremities and syndromes of multiple systems, as well as Down's syndrome, increased with increasing paternal age. For example, in comparison with fathers age 20-29 years, adjusted hazard ratio of syndromes of multiple systems was 1.15 [95% confidence interval (CI) 0.81-1.65] for age 35-39 years, 1.33 (95% CI 0.79-2.25) for age 40-44 years, 1.73 (95% CI 0.82-3.65) for age 45-49 years, and 3.20 (95% CI 1.37-7.48) for age > or = 50 years (test for trend P = 0.01). CONCLUSIONS: Our data suggest that advanced paternal age may be associated with an excess occurrence of some specific malformations. The association could be caused by mutations of the gametes in men induced by biological or environmental factors.

Abnormalities, Multiple↗
PubMed2005

Paternal age and preterm birth.

BACKGROUND: There is growing evidence that advanced paternal age can be a reproductive hazard. METHODS: We studied couples and their first children using nationwide registers in Denmark between 1980 and 1996. We restricted the analysis to mother's age 20-29 years. We estimated odds ratios (ORs) of preterm (< 37 weeks gestation) and very preterm birth (< 32 weeks) as a function of paternal age using logistic regression to adjust for potential confounding variables. RESULTS: The risk of preterm birth increased with paternal age, almost entirely resulting from an association for very preterm birth. Compared with fathers age 20-24 years, ORs for very preterm birth were 1.3 (age 25-29), 1.4 (age 35-39), 1.7 (age 40-44), 1.6 (age 45-49), and 2.1 (age 50+) (test for trend: P = 0.01). CONCLUSIONS: Risk of very preterm birth increases among older fathers, perhaps as a result of a paternal placental effect.

Adult↗
PubMed2005

Two definitions of "small size at birth" as predictors of motor development at six months.

BACKGROUND: Small babies are known to be at increased risk for a wide range of difficulties. In predicting risk, it may be more informative to estimate smallness in relation to family norm (using the birth weight of an older sibling) rather than to use the standard "small-for-gestational-age" (SGA z-score) measure. METHODS: For 10,577 babies born to women enrolled in the Danish National Birth Cohort, we calculated a "birth-weight ratio" (actual birth weight/expected birth weight predicted from older sibling x 100). We identified babies in the lowest decile of the birth-weight ratio (</=87.7% for boys and </=87.6% for girls) and compared them with babies in the lowest decile of the sex- and gestational age-specific distribution (SGA z-score). We evaluated how these definitions predicted motor development. We also compared how selected predictors of birth weight influenced the classification of the baby according to the birth-weight ratio and according to the SGA z-score. RESULTS: Birth-weight ratio and SGA identified 1058 and 1059 babies, respectively, with 738 identified by both methods. A low birth-weight ratio predicted delayed motor development slightly better than did SGA. Babies classified as too small solely by the SGA criterion were more often born to small or smoking mothers than those identified solely by the birth-weight ratio. CONCLUSIONS: The combined use of the birth-weight ratio and SGA may provide a more sensitive tool for identifying babies at risk. The birth-weight ratio is less likely to classify babies as small based on their mothers' body size, identifying instead babies who were substantially smaller than their sibling.

Adult↗
PubMed2004

Fecundity and twinning. A study within the Danish National Birth Cohort.

BACKGROUND: Decreased fecundity has been hypothesized as one of the causes of the widespread decline in twin rates in the 1960s and 1970s. The association between high fecundity and twinning is not, however, well documented. METHODS: In the Danish National Birth Cohort, we identified 56 295 births (including 729 twin deliveries) with data on pregnancy planning and time to pregnancy (TTP) and no report of infertility treatment. We estimated the odds ratio (OR) of twinning as a function of TTP and having planned a pregnancy. RESULTS: Increasing TTP correlated with decreased twinning rates. Compared with women who conceived within 2 months of trying, women who took longer than 1 year had an OR of 0.55 (95% confidence interval 0.39-0.77) of giving birth to twins. The association was slightly stronger for opposite sex twins. Women not planning a pregnancy had a lower rate of opposite sex twins than planners, but a comparable rate of same sex twins. We saw an excess of same sex pairs in women conceiving despite contraception. CONCLUSIONS: A long TTP is associated with a reduced risk of twinning. The marked decline observed in the 1960s and 1970s may derive from a widespread decrease in fecundity.

Adult↗
PubMed2004

Height and risk of severe pre-eclampsia. A study within the Danish National Birth Cohort.

BACKGROUND: Pre-eclampsia shares a number of risk factors with cardiovascular disease (CVD). Women with recurrent pre-eclampsia or pre-eclampsia early in pregnancy reportedly have an increased long-term risk of CVD. Short stature is a risk factor for CVD but has rarely been examined in relation to pre-eclampsia. METHODS: We used data from 59 968 singleton live births in the Danish National Birth Cohort born between 1998 and 2001 to assess risk of severe pre-eclampsia/eclampsia (296 cases) in relation to self-reported height. We examined the association in multiple logistic regressions stratified by parity. RESULTS: Among primiparas there was a weak association (compared with women <165 cm, women >172 cm had on OR of 0.79, 95% CI: 0.55, 1.14). Among multiparas, the tallest women had an adjusted OR of 0.42 (95% CI: 0.20, 0.87) of developing severe pre-eclampsia compared with women <165 cm. The OR per centimetre was 0.94 (95% CI: 0.91, 0.97). Self-reported pre-existing hypertension did not explain this association, which also persisted when the analysis was restricted to non-overweight women. CONCLUSIONS: Short stature was associated with a higher risk of severe pre-eclampsia in multiparas participating in the Danish National Birth Cohort.

Body Height↗
PubMed2004

Prenatal maternal alcohol consumption and hospitalization with asthma in childhood: a population-based follow-up study.

BACKGROUND: Asthma may have a prenatal origin. We examined whether maternal alcohol consumption during pregnancy increases the risk of hospitalization with asthma in children. METHODS: We conducted a follow-up study on 10,440 singletons born at approximately 36 weeks of gestation or later to mothers attending midwife centers between April 1984 and April 1987 in Denmark. The mothers completed a questionnaire regarding lifestyle and socioeconomic factors, including alcohol consumption. The children were followed up through the Danish Hospital Discharge Registry. We determined the first hospitalization with a discharge diagnosis of asthma as recorded in the Danish Hospital Discharge Registry. RESULTS: Most pregnant women (81.5%) drank at least some alcohol during pregnancy, but only a few (2.1%) consumed 120 g or more per week. In total, 307 children were hospitalized at least once with a discharge diagnosis of asthma during follow-up (the cumulative incidence risk was 3.5% from birth to 12 years of age or the end of follow-up). After adjusting for maternal socioeconomic factors, dietary components, and other lifestyle factors, children whose mothers drank alcohol during pregnancy did not have an increased risk of hospitalization with asthma compared with the children of mothers who reported no alcohol consumption during pregnancy (adjusted incidence rate ratio, 0.95; 95% confidence interval, 0.70-1.29). Further analyses showed no association with the dose and type of alcohol or with binge drinking. CONCLUSIONS: The study provides no support for a causal link between maternal alcohol intake during pregnancy and asthma in childhood.

Alcohol Drinking↗
PubMed2004

Multiple sclerosis in women having children by multiple partners. A population-based study in Denmark.

We investigated whether having children with multiple men is a risk factor for being diagnosed with multiple sclerosis (MS). We studied a cohort of 151,328 women, of whom 64,704 had different men fathering their children and 86,624 the same partner for all births. Women were included if they had a second or higher parity child between 1973 and 1996. The follow-up for MS ended in 1997. There were a total of 213 cases of MS diagnosed during the study period. We analysed data through Poisson regression models. Women having children with different men were not at higher risk of being diagnosed with MS, with the possible exception of a short period after having a baby with a new partner. Women having children with more than one man may have a higher risk of a pregnancy accelerating the diagnosis of MS but are probably not at an overall higher risk of MS.

Adult↗