17-α hydroxyprogesterone caproate for the prevention of preterm birth

17?α hydroxyprogesterone caproate is a synthetic form of the natural progestin 17-α hydroxyprogesterone that is US FDA approved for the prevention of recurrent spontaneous preterm birth in women with a history of a prior singleton preterm birth. For women with a history of a prior spontaneous preterm birth between 20 weeks and 36 weeks and 6 days of gestation, the use of 17-α hydroxyprogesterone caproate has been shown to reduce the risk of recurrent preterm birth by more than 30%. This medication is the only drug currently FDA approved for the prevention of preterm birth, and it is the first drug the FDA has approved for use exclusively during pregnancy in approximately 15 years.     

Is paternal age associated with an increased risk of low birthweight,preterm delivery,and multiple birth?

OBJECTIVE: To determine if paternal age elevates the risk of low birthweight (< 2500g, LBW), preterm birth (< 37 weeks gestation), and multiple gestation among mothers whose age does not predict an elevated risk. DESIGN/METHODS: Population data on birth outcome, maternal age and paternal age was obtained from Alberta Health and Wellness for all births 1990-1996. RESULTS: Among women aged 25 to 29, regardless of parity, there was no linear relationship between paternal age and preterm birth or LBW. However, multiple birth rates increased with increased paternal age (p < 0.01). Among singleton births, advanced paternal age (>50 years) increased the risk of LBW and preterm birth (p < 0.05). CONCLUSIONS: Paternal age is not a risk factor for LBW or preterm delivery among low risk women. The increased risk of multiple birth with increased paternal age, regardless of parity, requires confirmation among other populations.     

Are racial disparities in preterm birth larger in hypersegregated areas?

The causes of the racial/ethnic disparity in preterm birth (PTB) remain largely unknown; traditional risk factors such as smoking and prenatal care fail to account for it. The authors examined whether living in metropolitan areas (MAs) with high levels of residential racial segregation along multiple dimensions (hypersegregation) was associated with higher rates of PTB or larger racial disparities in PTB and whether segregation modified the established race-age association in PTB. The authors merged 2000 natality data (n = 1,944,703) with US Census measures of Black-White hypersegregation. They executed two-level hierarchical logistic regression analyses among White and Black mothers in 237 MAs to estimate the odds of PTB by hypersegregation, race, and age, after controlling for covariates. In unadjusted and adjusted models, Black infants in hypersegregated MAs were more likely to be preterm than Black infants in nonhypersegregated MAs (p < 0.001). Black-White PTB disparities were larger in hypersegregated areas than in nonhypersegregated areas (p < 0.001), and the age-race association with PTB was modified by hypersegregation (p < 0.001). Living in a hypersegregated MA had a more pronounced association with PTB among older Black women, and racial disparities in PTB were larger in hypersegregated areas among older mothers (p < 0.001). Since over 40% of Black childbearing women live in hypersegregated areas, residential segregation may be an important social determinant of racial birth disparities.     

Rising preterm birth rates, 1989–2004: Changing demographics or changing obstetric practice?

Preterm birth rates are higher in the United States than in most industrialized countries, and have been rising steadily. Some attribute these trends to changing demographics, with more older mothers, more infertility, and more multiple births. Others suggest that changes in obstetrics are behind the trends. We sought to determine what the preterm birth rate in 2004 would have been if demographic factors had not changed since 1989. We examined complete US birth certificate files from 1989 and 2004 and used logistic regression models to estimate what the 2004 preterm birth rates (overall, spontaneous, and medically induced) would have been if maternal age, race, nativity, gravidity, marital status, and education among childbearing women had not changed since 1989. While the overall preterm births increased from 11.2% to 12.8% from 1989 to 2004, medically induced rates increased 94%, from 3.4% to 6.6%, and spontaneous rates declined by 21%, from 7.8% to 6.2%. Had demographic factors in 2004 been what they were in 1989, the 2004 rates would have been almost identical. Changes in multiple births accounted for only 16% of the increase in medically induced rates. Our analysis suggests that the increase in preterm births is more likely due primarily to changes in obstetric practice, rather than to changes in the demographics of childbearing. Further research should examine the degree to which these changes in obstetric practice affect infant morbidity and mortality.     

Factors associated with preterm birth in Campina Grande, Paraíba State, Brazil: a case-control study

A case-control study (2008-2009) analyzed risk factors for preterm birth in the city of Campina Grande, Paraíba State, Brazil. A total of 341 preterm births and 424 controls were included. A multiple logistic regression model was used. Risk factors for preterm birth were: previous history of preterm birth (OR = 2.32; 95%CI: 1.25-4.29), maternal age (OR = 2.00; 95%CI: 1.00-4.03), inadequate prenatal care (OR = 2.15; 95%CI: 1.40-3.27), inadequate maternal weight gain (OR = 2.33; 95%CI: 1.45-3.75), maternal physical injury (OR = 2.10; 95%CI: 1.22-3.60), hypertension with eclampsia (OR = 17.08; 95%CI: 3.67-79.43) and without eclampsia (OR = 6.42; 95%CI: 3.50-11.76), hospitalization (OR = 5.64; 95%CI: 3.47-9.15), altered amniotic fluid volume (OR = 2.28; 95%CI: 1.32-3.95), vaginal bleeding (OR = 1.54; 95%CI: 1.01-2.34), and multiple gestation (OR = 22.65; 95%CI: 6.22-82.46). High and homogeneous prevalence of poverty and low maternal schooling among both cases and controls may have contributed to the fact that socioeconomic variables did not remain significantly associated with preterm birth.     

Very preterm birth: who has access to antenatal corticosteroid therapy?

Burguet A, Ferdynus C, Thiriez G, Bouthet M‐F, Kayemba‐Kays S, Sanyas P, Menget A, Mulin B, Riethmuller D, Maillet R, Brousse C, Magnin G, Boisselier P, Sagot P, Pierre F, Gouyon B, Gouyon J‐B. Very preterm birth: who has access to antenatal corticosteroid therapy? Paediatric and Perinatal Epidemiology 2010; 24: 63–74. We describe the administration of antenatal corticosteroid therapy (ACT) for liveborn very preterm neonates in a population‐based study. A total of 790 very preterm neonates (between 24 and 31 full weeks of gestation) were included in this regionally defined population of very preterm neonates in France. The main outcome measure was non‐access to ACT. Data were analysed using logistic and polytomous models to control for neonatal and sociodemographic characteristics, mechanisms of very preterm birth and neonatal network organisation. As compared with level III, births in levels I‐II maternity units were closely related to non‐access to ACT (60.1% vs. 8.8%), but not to pregnancy follow‐up (19.7% vs. 17.8%). Only 6.3% of very preterm neonates that benefited from antepartum referral did nor receive ACT. Births associated with rupture of membranes and gestational hypertension were significantly more often transferred to level‐III units (73.8% and 68.3% respectively) than those due to maternal bleeding and spontaneous labour (57.0% and 50.7% respectively), and the neonates had a lower probability of not receiving ACT (8.5%, 11.5%, 23.0%, 31.2% respectively). Very preterm neonates referred in utero to a level‐III unit came from a more favourable socio‐economic environment. Non‐access to ACT was more often observed in neonates born to 14‐ to 24‐year‐old mothers, smokers, of low socio‐economic status, and preterm birth resulting from maternal bleeding or spontaneous labour. These data from a French regional study show that access to ACT is not only explained by practitioners' support of recommendations. In our population‐based study, ACT access was related to socio‐economic factors and to the mechanisms of very preterm birth. Improving the rate of access to ACT should take these organisational, medical and socio‐economic dimensions into account.     

Contrasting socioeconomic gradients in small for gestational age and preterm birth in Argentina, 2003–2007

Objectives

To examine the socioeconomic gradients in birth outcomes among singleton infants in Argentina, 2003–2007.

Methods

We analyzed data of 3,230,031 singleton infants born in 2003–2007, obtained from vital statistics. Associations between birth outcomes [small for gestational age (SGA), low birth weight (LBW), and preterm birth (PTB)] and socioeconomic indicators (maternal education and area-based material deprivation quintiles) were assessed with logistic regression.

Results

The risk of SGA increased with higher socioeconomic disadvantage, but that of PTB decreased. Compared to mothers who attained a tertiary or university degree, mothers who did not complete primary school were more likely to have a SGA infant [adjusted OR (95 % CI): 1.65 (1.62, 1.68)], but less likely to deliver preterm [0.92 (0.90, 0.94)]. As a result of the conflicting trends in SGA and PTB, LBW exhibited inconsistent socioeconomic gradients.

Conclusions

The excess risk of adverse birth outcomes associated with socioeconomic disadvantage was consistently reflected by SGA, but not by LBW and PTB. These findings challenge the usefulness of LBW as an indicator population health. Further research is needed to explain the reverse socioeconomic gradients in PTB.     

Are gestational age,birth weight,and birth length indicators of favorable fetal growth conditions? A structural equation analysis of Filipino infants

The fetal origins hypothesis emphasizes the life‐long health impacts of prenatal conditions. Birth weight, birth length, and gestational age are indicators of the fetal environment. However, these variables often have missing data and are subject to random and systematic errors caused by delays in measurement, differences in measurement instruments, and human error. With data from the Cebu (Philippines) Longitudinal Health and Nutrition Survey, we use structural equation models, to explore random and systematic errors in these birth outcome measures, to analyze how maternal characteristics relate to birth outcomes, and to take account of missing data. We assess whether birth weight, birth length, and gestational age are influenced by a single latent variable that we call favorable fetal growth conditions (FFGC) and if so, which variable is most closely related to FFGC. We find that a model with FFGC as a latent variable fits as well as a less parsimonious model that has birth weight, birth length, and gestational age as distinct individual variables. We also demonstrate that birth weight is more reliably measured than is gestational age. FFGCs were significantly influenced by taller maternal stature, better nutritional stores indexed by maternal arm fat and muscle area during pregnancy, higher birth order, avoidance of smoking, and maternal age 20–35 years. Effects of maternal characteristics on newborn weight, length, and gestational age were largely indirect, operating through FFGC. Copyright © 2013 John Wiley & Sons, Ltd.     

Country of birth, socioeconomic position, and healthcare expenditure: a multilevel analysis of Malmö, Sweden

STUDY OBJECTIVE: The principle of equity aims to guarantee allocation of healthcare resources on the basis of need. Therefore, people with a low income and persons living alone are expected to have higher healthcare expenditures. Besides these individual characteristics healthcare expenditure may be influenced by country of birth. This study therefore aimed to investigate the role of country of birth in explaining individual healthcare expenditure. DESIGN: Multilevel regression model based on individuals (first level) and their country of birth (second level). SETTING: The city of Malm?, Sweden. PARTICIPANTS: All the 52 419 men aged 40-80 years from 130 different countries of birth, who were living in Malm?, Sweden, during 1999. MAIN RESULTS: At the individual level, persons with a low income and persons living alone showed a higher healthcare expenditure, with regression coefficients (and 95% confidence intervals) being 0.358 (0.325 to 0.392) and 0.197 (0.165 to 0.230), respectively. Country of birth explained a considerable part (18% and 13%) of the individual differences in the probability of having a low income and living alone, respectively. However, this figure was only 3% for having some health expenditure, and barely 0.7% with regard to costs in the 74% of the population with some health expenditure. CONCLUSIONS: Malm? is a socioeconomically segregated city, in which the country of birth seems to play only a minor part in explaining individual differences in total healthcare expenditure. These differences seem instead to be determined by individual low income and living alone.     

Families with birth defects: is birth weight of nonmalformed siblings affected?

Infants with congenital malformations have on average lower birth weight than do infants without malformations. Preterm delivery and low birth weight are known to recur in sibships. The aim of the study was to compare the birth weight of siblings to malformed infants with the birth weight of infants in families without malformed infants. Data were from the Medical Birth Registry in Norway from 1967 to 1998. Births were linked to their mothers through the unique personal identification number, providing sibship files with the mother as the observation unit. The study was based on 551,478 mothers with at least two singleton infants and 209,423 mothers with at least three singletons. The authors grouped the families according to whether and in which birth order an infant had a registered congenital malformation and compared birth weight and gestational age between infants of the same birth order in families with malformations and without. Overall, in families where one or two infants had a congenital malformation, the crude and adjusted mean birth weight of nonmalformed siblings did not differ from that of infants in unaffected families, whereas it was significantly reduced for the malformed infant itself. We conclude that reduced birth weight associated with congenital anomalies is specific to the affected pregnancy.     

Maternal fever,multivitamin use,and selected birth defects: evidence of interaction?

BACKGROUND: Multivitamin use has been associated with lower risks for some birth defects. We evaluated whether multivitamin use modified birth defect risks associated with febrile illness, a common and possibly teratogenic exposure. METHODS: From the population-based Atlanta Birth Defects Case-Control Study (1968-1980) we selected seven defects (neural tube defects, cleft lip and palate, cardiac outflow tract defects, ventricular septal defects, atrial septal defects, omphalocele, and limb deficiencies) because of their inverse relation with multivitamin supplement use documented in previous analyses. We defined four exposure categories from combinations of multivitamin use (periconceptional use compared with no use) and febrile illness (early pregnancy compared with no illness). The reference category was no multivitamin use and no illness. RESULTS: Febrile illness with no multivitamin use was associated with generally increased risk for the seven defects and the combined group (odds ratio = 2.1, 1.7, 1.5, 1.9, 2.9, 4.4, 3.3, and 2.3, respectively). With multivitamin use, however, the risk estimates associated with febrile illness were generally lower (odds ratio = 0.6, 1.1, 0.0, 1.5, 0.0, 0.8, 0.0, and 0.8, respectively). Some of the associated 95% confidence intervals included one. CONCLUSIONS: The pattern of findings suggests that multivitamin use might decrease the risk associated with febrile illness.     

Does alcohol increase the risk of preterm delivery?

We evaluated the association between alcohol intake during pregnancy and preterm delivery. Women attending routine antenatal care at Aarhus University Hospital, Denmark, from 1989-1991 and 1992-1996 were eligible. We included 18,228 singleton pregnancies in the analyses. We obtained prospective information on alcohol intake at 16 and 30 weeks of gestation, other lifestyle factors, maternal characteristics, and obstetrical risk factors from self-administered questionnaires and hospital files. For women with alcohol intake of 1-2, 3-4, 5-9, and > or =10 drinks/week the risk ratio (RR) of preterm delivery was 0.91 (95% CI = 0.76-1.08), 0.86 (95% CI = 0.64-1.15), 0.89 (95% CI = 0.52-1.52), and 2.93 (95% CI = 1.52-5.63), respectively, compared with intake of <1 drink/week at 16 weeks gestation, and 0.69 (95% CI = 0.56-0.86), 0.82 (95% CI = 0.60-1.13), 0.97 (95% CI = 0.58-1.64), and 3.56 (95% CI = 1.78-7.13) at 30 weeks. Adjustment for smoking habits, caffeine intake, age, height, pre-pregnant weight, marital status, occupational status, education, parity, chronic diseases, previous preterm delivery, mode of initiation of labor, and sex of the child did not change the conclusions, nor did restriction of the highest intake group to women drinking 10-14 drinks/week (RR = 3.41 (1.71-6.81) at 16 weeks and RR = 3.47 (1.64-7.35) at 30 weeks).