Abstract: Rationale Benefits of identifying risk factors for bronchopulmonary dysplasia in extremely premature infants include providing prognostic information, identifying infants likely to benefit from preventive strategies, and stratifying infants for clinical trial enrollment. Objectives To identify risk factors for bronchopulmonary dysplasia, and the competing outcome of death, by postnatal day; to identify which risk factors improve prediction; and to develop a Web-based estimator using readily available clinical information to predict risk of bronchopulmonary dysplasia or death. Methods We assessed infants of 23-30 weeks' gestation born in 17 centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network and enrolled in the Neonatal Research Network Benchmarking Trial from 2000-2004. Measurements and main results Bronchopulmonary dysplasia was defined as a categorical variable (none, mild, moderate, or severe). We developed and validated models for bronchopulmonary dysplasia risk at six postnatal ages using gestational age, birth weight, race and ethnicity, sex, respiratory support, and Fi(O(2)), and examined the models using a C statistic (area under the curve). A total of 3,636 infants were eligible for this study. Prediction improved with advancing postnatal age, increasing from a C statistic of 0.793 on Day 1 to a maximum of 0.854 on Day 28. On Postnatal Days 1 and 3, gestational age best improved outcome prediction; on Postnatal Days 7, 14, 21, and 28, type of respiratory support did so. A Web-based model providing predicted estimates for bronchopulmonary dysplasia by postnatal day is available at https://neonatal.rti.org. Conclusions The probability of bronchopulmonary dysplasia in extremely premature infants can be determined accurately using a limited amount of readily available clinical information.

Abstract: Context Current guidelines, initially published in 1995, recommend antenatal corticosteroids for mothers with preterm labor from 24 to 34 weeks' gestational age, but not before 24 weeks due to lack of data. However, many infants born before 24 weeks' gestation are provided intensive care. Objective To determine if use of antenatal corticosteroids is associated with improvement in major outcomes for infants born at 22 and 23 weeks' gestation. Design, Setting, and Participants Cohort study of data collected prospectively on inborn infants with a birth weight between 401 g and 1000 g (N = 10 541) born at 22 to 25 weeks' gestation between January 1, 1993, and December 31, 2009, at 23 academic perinatal centers in the United States. Certified examiners unaware of exposure to antenatal corticosteroids performed follow-up examinations on 4924 (86.5%) of the infants born between 1993 and 2008 who survived to 18 to 22 months. Logistic regression models generated adjusted odds ratios (AORs), controlling for maternal and neonatal variables. Main Outcome Measures Mortality and neurodevelopmental impairment at 18 to 22 months' corrected age. Results Death or neurodevelopmental impairment at 18 to 22 months was significantly lower for infants who had been exposed to antenatal corticosteroids and were born at 23 weeks' gestation (83.4% with exposure to antenatal corticosteroids vs 90.5% without exposure; AOR, 0.58 [95% CI, 0.42-0.80]), at 24 weeks' gestation (68.4% with exposure to antenatal corticosteroids vs 80.3% without exposure; AOR, 0.62 [95% CI, 0.49-0.78]), and at 25 weeks' gestation (52.7% with exposure to antenatal corticosteroids vs 67.9% without exposure; AOR, 0.61 [95% CI, 0.50-0.74]) but not in those infants born at 22 weeks' gestation (90.2% with exposure to antenatal corticosteroids vs 93.1% without exposure; AOR, 0.80 [95% CI, 0.29-2.21]). If the mothers had received antenatal corticosteroids, the following events occurred significantly less in infants born at 23, 24, and 25 weeks' gestation: death by 18 to 22 months; hospital death; death, intraventricular hemorrhage, or periventricular leukomalacia; and death or necrotizing enterocolitis. For infants born at 22 weeks' gestation, the only outcome that occurred significantly less was death or necrotizing enterocolitis (73.5% with exposure to antenatal corticosteroids vs 84.5% without exposure; AOR, 0.54 [95% CI, 0.30-0.97]). Conclusion Among infants born at 23 to 25 weeks' gestation, antenatal exposure to corticosteroids compared with nonexposure was associated with a lower rate of death or neurodevelopmental impairment at 18 to 22 months.

Abstract: Preterm delivery is a powerful predictor of newborn morbidity and mortality. Such problems are due to not only immaturity but also the pathologic factors (such as infection) that cause early delivery. The understanding of these underlying pathologic factors is incomplete at best. To the extent that unmeasured pathologies triggering preterm delivery also directly harm the fetus, they will confound the association of early delivery with neonatal outcomes. This, in turn, complicates studies of newborn outcomes more generally. When investigators analyze the association of risk factors with neonatal outcomes, adjustment for gestational age as a mediating variable will lead to bias. In the language of directed acyclic graphs, gestational age is a collider. The theoretical basis for colliders has been well described, and gestational age has recently been acknowledged as a possible collider. However, the impact of this problem, as well as its implications for perinatal research, has not been fully appreciated. The authors discuss the evidence for confounding and present simulations to explore how much bias is produced by adjustments for gestational age when estimating direct effects. Under plausible conditions, frank reversal of exposure-outcome associations can occur. When the purpose is causal inference, there are few settings in which adjustment for gestational age can be justified.

Abstract: Objective: The objective of this study was to compare international trends in pre-eclampsia rates and in overall pregnancy hypertension rates (including gestational hypertension, pre-eclampsia and eclampsia). Design: Population data (from birth and/or hospital records) on all women giving birth were available from Australia (two states), Canada (Alberta), Denmark, Norway, Scotland, Sweden and the USA (Massachusetts) for a minimum of 6 years from 1997 to 2007. All countries used the 10th revision of the International Classification of Diseases, except Massachusetts which used the 9th revision. There were no major changes to the diagnostic criteria or methods of data collection in any country during the study period. Population characteristics as well as rates of pregnancy hypertension and pre-eclampsia were compared. Results: Absolute rates varied across the populations as follows: pregnancy hypertension (3.6% to 9.1%), pre-eclampsia (1.4% to 4.0%) and early-onset preeclampsia (0.3% to 0.7%). Pregnancy hypertension and/or pre-eclampsia rates declined over time in most populations. This was unexpected given that factors associated with pregnancy hypertension such as prepregnancy obesity and maternal age are generally increasing. However, there was also a downward shift in gestational age with fewer pregnancies reaching 40 weeks.

Abstract: Placental dysfunction leading to fetal growth restriction (FGR) is an important risk factor for neurodevelopmental delay. Recent observations clarify that FGR evolves prenatally from a preclinical phase of abnormal nutrient and endocrine milieu to a clinical phase that differs in characteristics in preterm and term pregnancies. Relating childhood neurodevelopment to these prenatal characteristics offers potential advantages in identifying mechanisms and timing of critical insults. Based on available studies, lagging head circumference, overall degree of FGR, gestational age, and umbilical artery (UA), aortic and cerebral Doppler parameters are the independent prenatal determinants of infant and childhood neurodevelopment. While head circumference is important independent of gestational age, overall growth delay has the greatest impact in early onset FGR. Gestational age has an overriding negative effect on neurodevelopment until 32-34 weeks' gestation. Accordingly, the importance of Doppler status is demonstrated from 27 weeks onward and is greatest when there is reversed end-diastolic velocity in the UA or aorta. While these findings predominate in early-onset FGR, cerebral vascular impedance changes become important in late onset FGR. Abnormal motor and neurological delay occur in preterm FGR, while cognitive effects and abnormalities that can be related to specific brain areas increase in frequency as gestation advances, suggesting different pathophysiology and evolving vulnerability of the fetal brain. Observational and management studies do not suggest that fetal deterioration has an independent impact on neurodevelopment in early-onset FGR. In late-onset FGR further research needs to establish benefits of perinatal intervention, as the pattern of vulnerability and effects of fetal deterioration appear to differ in the third trimester.

Abstract: In a cluster-randomized trial, Riitta Luoto and colleagues find that counseling on diet and activity can reduce the birthweight of babies born to women at risk of developing gestational diabetes mellitus (GDM), but fail to find an effect on GDM.

Abstract: Study objectives Preterm birth (PTB) is a major public health priority and the most common adverse pregnancy outcome. Several risk factors have been identified, but a gap in the understanding of the underlying etiology of PTB persists. Poor sleep quality is a correlate of adverse health outcomes. Therefore, we evaluated whether sleep quality during pregnancy was a clinically relevant risk factor for PTB. Design Observational. Measurements and results Participants included 166 pregnant women (mean age = 28.6 ± 5.5 years). Self-report questionnaires, including the Pittsburgh Sleep Quality Index (PSQI), were administered at 14-16, 24-26, and 30-32 weeks gestation. Logistic regression models were used to evaluate whether sleep quality was associated with preterm delivery. Poor sleep quality was a predictor of preterm birth, with the largest effects in early pregnancy (14-16 weeks) (OR: 1.25 95% CI [1.04-1.50], P = 0.02) and more modest effects in later pregnancy (30-32 weeks) (OR: 1.18 95% CI [0.98-1.42], P = 0.07). With every one-point increase on the PSQI, the odds of preterm birth increase 25% in early pregnancy and 18% in later pregnancy. Conclusions Poor sleep quality, in both early and late pregnancy, is associated with an increased risk of delivering preterm. Currently the specific pathway(s) through which disturbed sleep contributes to PTB are unknown. We suggest that poor sleep may contribute to increased risk for PTB both independently, as well as in conjunction with other established risk factors, such as stress.

Abstract: Objective:To identify the impact of timing of prenatal stress exposure on offspring risk for shortened gestational age, preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA), using a population-based sample.Methods:Swedish longitudinal population registries were linked to

Abstract: Background—Prior studies showing an inverse relationship between low birth weight in offspring and maternal risks of cardiovascular diseases (CVD) are limited by lack of information on gestational age and/or insufficient adjustment for confounders. Methods and Results—In a nationwide Swedish study, we included information on 923 686 women and their first singleton births between 1983 and 2005. Cox proportional hazards models were used to study associations between gestational length, fetal growth, and maternal incident hospitalization or death from CVD (coronary heart disease, cerebrovascular events, and heart failure). Multivariable adjusted models accounted for birth year, income, education, country of birth, smoking, diabetes mellitus, hypertension, and preeclampsia. The risk of maternal CVD increased with decreasing gestational age whereas the risk increase related to fetal growth appeared to be restricted to very small-for-gestational-age (SGA) infants. Compared with mothers of non-SGA infants born a...

Abstract: Background: Infliximab (IFX) and adalimumab (ADA) are attractive treatment options in patients with inflammatory bowel disease (IBD) also during pregnancy but there is still limited data on the benefit/risk profile of IFX and ADA during pregnancy. Methods: This observational study assessed pregnancy outcomes in 212 women with IBD under antitumor necrosis factor alpha (TNF) treatment at our IBD unit. Pregnancy outcomes in 42 pregnancies with direct exposure to anti-TNF treatment (35 IFX, 7 ADA) were compared with that in 23 pregnancies prior to IBD diagnosis, 78 pregnancies before start of IFX, 53 pregnancies with indirect exposure to IFX, and 56 matched pregnancies in healthy women. Results: Thirty-two of the 42 pregnancies ended in live births with a median gestational age of 38 weeks (interquartile range [IQR] 37–39). There were seven premature deliveries, six children had low birth weight, and there was one stillbirth. One boy weighed 1640 g delivered at week 33, died at age of 13 days because of necrotizing enterocolitis. A total of eight abortions (one patient wish) occurred in seven women. Trisomy 18 was diagnosed in one fetus of a mother with CD at age 37 under ADA treatment (40 mg weekly) and pregnancy was terminated. Pregnancy outcomes after direct exposure to anti-TNF treatment were not different from those in pregnancies before anti-TNF treatment or with indirect exposure to anti-TNF treatment but outcomes were worse than in pregnancies before IBD diagnosis. Conclusions: Direct exposure to anti-TNF treatment during pregnancy was not related to a higher incidence of adverse pregnancy outcomes than IBD overall. (Inflamm Bowel Dis 2011;)

Abstract: Background: Air pollution exposure during pregnancy might have trimester-specific effects on fetal growth. Objective: We prospectively evaluated the associations of maternal air pollution exposure with fetal growth characteristics and adverse birth outcomes in 7,772 subjects in the Netherlands. Methods: Particulate matter with an aerodynamic diameter < 10 μm (PM 10) and nitrogen dioxide (NO 2) levels were estimated using dispersion modeling at the home address. Fetal head circumference, length, and weight were estimated in each trimester by ultrasound. Information on birth outcomes was obtained from medical records. Results: In cross-sectional analyses, NO 2 levels were inversely associated with fetal femur length in the second and third trimester, and PM 10 and NO 2 levels both were associated with smaller fetal head circumference in the third trimester [-0.18 mm, 95% confidence interval (CI): -0.24, -0.12 mm; and -0.12 mm, 95% CI: -0.17, -0.06 mm per 1-μg/m 3 increase in PM 10 and NO 2, respectively]. Average PM 10 and NO 2 levels during pregnancy were not associated with head circumference and length at birth or neonatally, but were inversely associated with birth weight (-3.6 g, 95% CI: -6.7, -0.4 g; and -3.4 g, 95% CI: -6.2, -0.6 g, respectively). Longitudinal analyses showed similar patterns for head circumference and weight, but no associations with length. The third and fourth quartiles of PM 10 exposure were associated with preterm birth [odds ratio (OR) = 1.40, 95% CI: 1.03, 1.89; and OR = 1.32; 95% CI: 0.96, 1.79, relative to the first quartile]. The third quartile of PM10 exposure, but not the fourth, was associated with small size for gestational age at birth (SGA) (OR = 1.38; 95% CI: 1.00, 1.90). No consistent associations were observed for NO 2 levels and adverse birth outcomes. Conclusions: Results suggest that maternal air pollution exposure is inversely associated with fetal growth during the second and third trimester and with weight at birth. PM10 exposure was positively associated with preterm birth and SGA.

Abstract: OBJECTIVE: To evaluate the effects of intrauterine growth restriction (IUGR) with absent or reversed end-diastolic blood flow in the umbilical artery and very preterm birth on cognitive outcome at 5 to 8 years of age. METHODS: We studied 34 children with IUGR born at a median of 26.9 gestational weeks (GWs) (range: 24-29 GWs) (PT-IUGR), 34 matched preterm appropriate-for-gestational age (PT-AGA) children, and 34 term AGA children (T-AGA) by using the Wechsler Preschool and Primary Scale of Intelligence, Wechsler Intelligence Scale for Children, Strengths and Difficulties Questionnaire, and Brown's attention-deficit disorder (ADD) scales. RESULTS: The PT-IUGR group had mean (SD) scores on the verbal IQ (VIQ) and full-scale IQ (FSIQ) of 83.8 (17.3) and 78.9 (16.6), respectively, compared with the PT-AGA group, which had scores of 96.0 (14.5) and 90.1 (14.2) (P = .003 and P < .007), and the T-AGA group, which had scores of 101.3 (12) and 102.9 (13.2) (P < .001 and P < 001), respectively. The VIQ difference remained significant after adjustment for parental level of education, gestational age at birth, and neonatal morbidity. Performance IQ (PIQ) did not differ between the PT-IUGR and PT-AGA groups; their mean PIQs were lower than that of the T-AGA group (P < .001). Boys in the PT-IUGR group scored lower than girls in VIQ and FSIQ (P = .005 and .007, respectively). Behavior and ADD scores did not differ between the preterm groups. CONCLUSIONS: Children born very preterm after IUGR have an increased risk for cognitive impairment at early school age compared with children delivered very preterm for other reasons. Differences in cognitive outcome were restricted to boys who may have been especially vulnerable to the influence of IUGR and very preterm birth. Pediatrics 2011; 127: e874-e882 (Less)

Abstract: Chlamydia trachomatis infection is the most prevalent bacterial sexually transmitted infection and may influence pregnancy outcome. This study was conducted to assess the effect of chlamydial infection during pregnancy on premature delivery and birthweight. Pregnant women attending a participating midwifery practice or antenatal clinic between February 2003 and January 2005 were eligible for the study. From 4,055 women self-administered questionnaires and urine samples, tested by PCR, were analysed for C. trachomatis infection. Pregnancy outcomes were obtained from midwives and hospital registries. Gestational ages and birthweights were analysed for 3,913 newborns. The C. trachomatis prevalence was 3.9%, but varied by age and socio-economic background. Chlamydial infection was, after adjustment for potential confounders, associated with preterm delivery before 32 weeks (OR 4.35 [95% CI 1.3, 15.2]) and 35 weeks gestation (OR 2.66 [95% CI 1.1, 6.5]), but not with low birthweight. Of all deliveries before 32 weeks and 35 weeks gestation 14.9% [95% CI 4.5, 39.5] and 7.4% [95% CI 2.5, 20.1] was attributable to C. trachomatis infection. Chlamydia trachomatis infection contributes significantly to early premature delivery and should be considered a public health problem, especially in young women and others at increased risk of C. trachomatis infection.

Abstract: Objective To examine the association between gestational weight gain and maternal body mass index (BMI) among Vietnamese women and the risk of delivering an infant too small or too large for gestational age. Methods A prospective health-facility-based study of 2989 pregnant Vietnamese women was conducted in the city of Nha Trang in 2007–2008. Cubic logistic regression was used to investigate the association of interest. Infants were classified into weight-forgestational-age categories according to weight centiles for the Asian population. Gestational age was based on the date of last menstrual period and adjusted by the results of first-trimester ultrasound. Findings BMI was low (< 18.5), normal (18.5–22.9) and high (≥ 23.0) in 26.1%, 65.4% and 8.5% of the women, respectively. In each of these BMI categories, the percentage of women who delivered infants too small for gestational age was 18.1, 10.0 and 9.4, respectively, and the mean gestational weight gain was 12.5 kg (standard deviation, SD: ± 3.6), 12.2 kg (SD: ± 3.8) and 11.5 kg (SD: ± 4.7), respectively. Among women with low BMI, the risk of delivering an infant too small for gestational age ranged from approximately 40% if the gestational weight gain was < 5 kg to 20% if it was 5–10 kg. Conclusion Having a low BMI, commonly found in Viet Nam, puts women at risk of delivering an infant too small for gestational age, especially when total maternal gestational weight gain is < 10 kg.

Abstract: OBJECTIVES: This report presents 2007 period infant mortality statistics from the linked birth/infant death data set (linked file) by a variety of maternal and infant characteristics. The linked file differs from the mortality file, which is based entirely on death certificate data. METHODS: Descriptive tabulations of data are presented and interpreted. RESULTS: The U.S. infant mortality rate was 6.75 infant deaths per 1,000 live births in 2007, not significantly different than the rate of 6.68 in 2006. Infant mortality rates ranged from 4.57 per 1,000 live births for mothers of Central and South American origin to 13.31 for non-Hispanic black mothers. Infant mortality rates were higher for those infants who were born in multiple deliveries; for those whose mothers were born in the 50 states or the District of Columbia; and for mothers who were unmarried. Infant mortality was also higher for male infants and infants born preterm or at low birthweight. The neonatal mortality rate was essentially unchanged from 2006 (4.46) to 2007 (4.42). The postneonatal mortality rate increased 5 percent from 2.22 in 2006 to 2.33 in 2007, similar to the rate in 2005 (2.32). Infants born at the lowest gestational ages and birthweights have a large impact on overall U.S. infant mortality. For example, more than one-half of all infant deaths in the United States in 2007 (54 percent) occurred to the 2 percent of infants born very preterm (less than 32 weeks of gestation). Still, infant mortality rates for late preterm infants (34-36 weeks of gestation) were 3.6 times, and those for early term (37-38 weeks) infants were 1.5 times, those for infants born at 39-41 weeks of gestation, the gestational age with the lowest infant mortality rate. The three leading causes of infant death--congenital malformations, low birthweight, and sudden infant death syndrome--accounted for 45 percent of all infant deaths. The percentage of infant deaths that were "preterm-related" was 36.0 percent in 2007. The preterm-related infant mortality rate for non-Hispanic black mothers was 3.4 times higher, and the rate for Puerto Rican mothers was 71 percent higher than for non-Hispanic white mothers. Language: en

Abstract: Objective Preeclampsia (PE) has been classified into early- and late-onset disease. These two phenotypic variants of PE have been proposed to have a different pathophysiology. However, the gestational age cut-off to define ‘early’ versus ‘late’ PE has varied among studies. The objective of this investigation was to determine the prevalence of lesions consistent with maternal underperfusion of the placenta in patients with PE as a function of gestational age.

Abstract: OBJECTIVE: To determine whether mild and severe growth restriction at birth among preterm infants is associated with neonatal mortality and cerebral palsy and cognitive performance at 5 years of age and school performance at 8 years of age. METHODS: All 2846 live births between 24 and 32 weeks9 gestation from 9 regions in France in 1997 were included in a prospective observational study (the EPIPAGE [Etude Epidemiologique sur les Petits Ages Gestationnels] study) and followed until 8 years of age. Infants were classified as “small-for-gestational-age” (SGA) if their birth weight for gestational age was at the RESULTS: Among the children born between 24 and 28 weeks9 gestation, the mortality rate increased from 30% in the AGA group to 42% in the M-SGA group and to 62% in the SGA group (P CONCLUSIONS: In preterm children, growth restriction was associated with mortality, cognitive and behavioral outcomes, as well as school difficulties.

Abstract: In a cluster-randomized trial, Riitta Luoto and colleagues find that counseling on diet and activity can reduce the birthweight of babies born to women at risk of developing gestational diabetes mellitus (GDM), but fail to find an effect on GDM.

Abstract: Anti-Ro/SSA antibodies are associated with neonatal lupus (congenital heart block (CHB), neonatal transient skin rash, hematological and hepatic abnormalities), but do not negatively affects other gestational outcomes, and the general outcome of these pregnancies is now good, when followed by experienced multidisciplinary teams. The prevalence of CHB, defined as an atrioventricular block diagnosed in utero, at birth, or within the neonatal period (0–27 days after birth), in the offspring of an anti-Ro/SSA-positive women is 1–2%, of neonatal lupus rash around 10–20%, while laboratory abnormalities in asymptomatic babies can be detected in up to 27% of cases. The risk of recurrence of CHB is ten times higher. Most of the mothers are asymptomatic at delivery and are identified only by the birth of an affected child. Half of these asymptomatic women develop symptoms of a rheumatic disease, most commonly arthralgias and xerophtalmia, but few develop lupus nephritis. A standard therapy for CHB is still matter of investigation, although fluorinated corticosteroids have been reported to be effective for associated cardiomyopathy. Serial echocardiograms and obstetric sonograms, performed at least every 1–2 weeks starting from the 16th week of gestational age, are recommended in anti-Ro/SSA-positive pregnant women to detect early fetal abnormalities that might be a target of preventive therapy.

Abstract: Concerns exist about the adequacy of vitamin D in pregnant and lactating women. This review assesses the evidence that maternal vitamin D status influences maternal, fetal, and breast-fed infant bone health; maternal adverse outcomes (preeclampsia, gestational diabetes, obstructed labor, and infectious disease); fetal adverse outcomes (growth, gestational age, and developmental programming); and infant adverse outcomes. The evidence for all of these outcomes is contradictory (except for maternal infectious disease) and lacking causality; thus, it is inconclusive. The 2011 Dietary Reference Intakes for vitamin D and their implications for assessing vitamin D status are discussed. An estimated 5% to 29% of American pregnant women may have inadequate vitamin D status, with the higher prevalence in African Americans. Little is known about the prevalence of inadequacy in American lactating women. Research needs are also identified, especially the need for rigorous and well-designed randomized clinical trials to determine the role of vitamin D in nonbone health outcomes in pregnancy and lactation.

Abstract: Antenatal maternal stress is thought to negatively affect fetal development, birth outcomes, and infant’s development. Glucocorticoids are suggested to be a common link between prenatal stressors and infant’s health. However, data on these mechanisms are rare and sometimes conflicting. The objective of this study was to examine the effects of maternal distress during pregnancy on fetal development and birth weight in humans prospectively. This study focuses on cortisol as one mediating the mechanism of the association between maternal distress and birth outcomes. Pregnancy-related and general distress was measured in 81 women with uncomplicated, singleton pregnancies. The rise of salivary cortisol on awakening (CAR) was assessed in weeks 13–18 and 35–37 postmenstrual age of pregnancy. Mothers completed a structured interview, the perceived stress scale, a widely used psychological instrument that provided a global measure of perceived stress, as well as the Prenatal Distress Questionnaire, a self-report questionnaire designed to assess worries and anxiety in pregnancy. Pre-, peri-, and postnatal medical risk factors as well as birth characteristics were extracted from medical records routinely kept by the attending obstetricians. Hierarchical multiple regressions indicate that maternal cortisol levels explained 19.8% of the variance in birth weight and 9% of the variance in body length at birth, even after controlling for gestational age, parity, pre-pregnancy BMI, smoking, and infant’s sex. Newborns of mothers with higher cortisol levels in pregnancy had lower birth weights and were shorter at birth. An ANCOVA for repeated measures indicated that, after controlling for covariates, pregnancy-related as well as general distress in pregnancy did not influence cortisol levels after awakening (area under the curve). No significant associations between perceived stress and anthrometric measures at birth were found. In conclusion, maternal cortisol levels in pregnancy influence intrauterine growth and may be a better predictor for birth outcome than perceived stress.