The impact of maternal smoking on embryonic morphological development: the Rotterdam Periconception Cohort.

STUDY QUESTION: Is periconceptional maternal smoking associated with embryonic morphological development in ongoing pregnancies? SUMMARY ANSWER: Smoking during the periconceptional period is associated with a delayed embryonic morphological development which is not fully recuperated beyond the first trimester of pregnancy. WHAT IS KNOWN ALREADY: Smoking during pregnancy decreases prenatal growth, increasing the risk of preterm birth, small for gestational age (GA) and childhood obesity. STUDY DESIGN, SIZE, DURATION: Between 2010 and 2018, 689 women with ongoing singleton pregnancies were periconceptionally enrolled in a prospective cohort study with follow-up until 1 year after delivery. PARTICIPANTS/MATERIALS, SETTING, METHODS: Between 7 + 0 and 10 + 3 weeks, GA serial three-dimensional transvaginal ultrasound scans were performed. Embryonic morphological development as assessed by the Carnegie developmental stages was evaluated using Virtual Reality techniques. In the absence of fetal morphology classification methods beyond the embryonic period, fetal ultrasound measurements at around 20 weeks' GA, and birth weight were used to assess fetal growth. Linear mixed models were used to evaluate the association between smoking and the Carnegie stages. Regarding first-trimester morphological development, we additionally stratified our findings for mode of conception. Multiple linear regression models were used to study the association between smoking, fetal growth and birth weight. To investigate to which extent delayed embryonic morphological development mediated the effect of smoking, contemporary mediation analysis was used. Adjustments were made for potential confounders and other covariates. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 689 singleton ongoing pregnancies were included and 1210 Carnegie stages were determined. Maternal periconceptional smoking represented by the number of cigarettes/day was associated with a slight non-significant delay of the Carnegie stages (ßcigarettes/day = -0.058, 95% CI -0.122; 0.007, P = 0.080). Smoking of ≥10 cigarettes/day showed the strongest association (ß≥10 cigarettes/day = -0.352, 95% CI -0.648; -0.057, P = 0.019), as reflected by a 0.9-day delay in reaching the final Carnegie stage. Stratification for mode of conception showed a stronger negative association between the number of cigarettes/day in the IVF/ICSI group (ßcigarettes/day = -0.126, 95% CI -0.200; -0.051, P = 0.001) compared to naturally conceived pregnancies (ßcigarettes/day = 0.009, 95% CI -0.093; 0.111, P = 0.867). In the IVF/ICSI group, periconceptional smoking of ≥10 cigarettes/day was associated with in a 1.6 day delay in reaching the final Carnegie stage (ß≥10 cigarettes/day = -0.510, 95% CI -0.834; -0.186, P = 0.002). In the second trimester, periconceptional smoking was associated with a smaller femur length (ßcigarettes/day = -0.077, 95% CI -0.147; -0.008, P = 0.029) and a larger head circumference (ß1-9 cigarettes/day = 0.290, 95% CI 0.065; 0.514, P = 0.012). Smoking was associated with a lower birth weight, with a dose-response effect (ßcigarettes/day = -0.150, 95% CI -0.233; -0.068, P < 0.001). Furthermore, using the unadjusted model, 40-60% of the association between smoking and fetal ultrasound parameters and 6.3% of the association between smoking and birth weight can be explained by a delayed embryonic morphology. LIMITATIONS, REASONS FOR CAUTION: The study population was recruited from a tertiary referral center. Smoking habits were explored using self-reported questionnaires and checked for consistency by trained researchers. WIDER IMPLICATIONS OF THE FINDINGS: This study shows that the association of periconceptional maternal smoking and human morphological development can already be detected early in the first trimester of pregnancy using embryonic morphology as outcome. One of the key messages of this study is that the delay, or dysregulation, in embryonic morphology is associated with allometric growth reflected by smaller fetal measurements at 20 weeks gestation and lower weight at birth. The delay in embryonic morphology, measured in early pregnancy, cannot be recuperated during the pregnancy. The results of this study emphasize the importance of smoking intervention programs prior to conception. More research is warranted to assess the association between periconceptional smoking cessation and embryonic development. STUDY FUNDING/COMPETING INTEREST(S): The work was funded by the Department of Obstetrics and Gynaecology, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands. The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Publication rates in small German trials remained low five years after trial completion.

OBJECTIVE: To investigate publication rates in small trials and to explore which factors are associated with publication rates in small trials, including sample size, the type and number of primary and secondary outcomes. STUDY DESIGN AND SETTING: We studied a subgroup of 'small' trials from a pre-existing dataset (IntoValue), containing German trials completed between 2009 and 2017. Small trials were defined as phase II-III, III and IV trials with 150 or fewer participants. We performed an updated publication search and collected additional data from online trial records. RESULTS: Out of 499 trials, 325 (65%) trials published their results in a journal article or dissertation. Median time-to-publication was 3.41 years (95% CI: 3.04-4.10). Planned sample size was not associated with publication rates, but the difference between planned and achieved sample size was (per 10% unsuccessfully recruited participants, HR = 0.95, 95% CI: 0.91-1.00). Phase III vs. II-III trials, studied intervention (device vs. other) and clearly vs. unclearly defined primary outcomes predicted a higher likelihood of earlier publication. CONCLUSION: About 35% of small trials in Germany remain unpublished, even after an extensive follow-up period of over 9 years. Publication rates are low and were associated with sample size, trial phase and type of intervention.

Stimulation of thyroglobulin synthesis in thyroid polysomes by soluble factors from reticulocyte lysate.

The addition of rabbit reticulocyte lysate supernate to membrane-bound calf thyroid polysomes resulted in stimulation of [3H]leucine incorporation into acid-precipitable material; 91% of these total radioactive peptides was precipitated by thyroglobulin antibodies. The ability of reticulocyte lysate supernate to stimulate thyroglobulin syntheis was pH and temperature sensitive. The addition of 25 microM aurintricarboxylic acid resulted in an 85% inhibition of [3H]leucine incorporation.

Thyroid hormone regulates carnitine palmitoyltransferase Ialpha gene expression through elements in the promoter and first intron.

Carnitine palmitoyltransferase I (CPT-I) catalyzes the transfer of long chain fatty acyl groups from CoA to carnitine for translocation across the mitochondrial inner membrane. CPT-Ialpha is a key regulatory enzyme in the oxidation of fatty acids in the liver. CPT-Ialpha is expressed in all tissues except skeletal muscle and adipose tissue, which express CPT-Ibeta. Expression of CPT-Ialpha mRNA and enzyme activity are elevated in the liver in hyperthyroidism, fasting, and diabetes. CPT-Ialpha mRNA abundance is increased 40-fold in the liver of hyperthyroid compared with hypothyroid rats. Here, we examine the mechanisms by which thyroid hormone (T3) stimulates CPT-Ialpha gene expression. Four potential T3 response elements (TRE), which contain direct repeats separated by four nucleotides, are located 3000-4000 base pairs 5' to the start site of transcription in the CPT-Ialpha gene. However, only one of these elements functions as a TRE. This TRE binds the T3 receptor as well as other nuclear proteins. Surprisingly, the first intron of the CPT-Ialpha gene is required for the T3 induction of CPT-Ialpha expression, but this region of the gene does not contain a TRE. In addition, we show that CPT-Ialpha is induced by T3 in cell lines of hepatic origin but not in nonhepatic cell lines.

Differential regulation of carnitine palmitoyltransferase-I gene isoforms (CPT-I alpha and CPT-I beta) in the rat heart.

Carnitine palmitoyltransferase-I (CPT-I) is a major control point for fatty acid oxidation. Two kinetically different isoforms, CPT-I alpha and CPT-I beta, have been identified. Cardiac ventricular myocytes are the only cells known to express both CPT-I isoforms. In this study, we characterized the differential regulation of CPT-I alpha and CPT-I beta expression in the heart. Expression of the CPT-I alpha gene was very high in the fetal heart and declined following birth. CPT-I beta was also highly expressed in fetal myocytes and remained so throughout development. CPT-I alpha mRNA abundance was increased in both the liver and heart of diabetic or fasted rats, but CPT-I beta mRNA levels were not altered in these states. A high fat diet elevated expression of the CPT-I alpha gene in the liver but not in the heart. The fat content of the diet did not affect the expression of CPT-I beta. Cultures of neonatal rat cardiac myocytes were transfected with luciferase reporter genes driven by CPT-I alpha or CPT-I beta promoters. Two regions of the CPT-I alpha promoter, including an upstream region (-1300/-960) and a region in the proximal promoter (-193/-52) contributed equally to basal expression in cardiac myocytes. Basal transcription of CPT-I alpha was dependent on Sp1 sites and a CCAAT box in the proximal promoter. Our data indicate that the CPT-I beta gene is expressed in a tissue specific manner, but that it is not subject to the same developmental or hormonal controls imposed on CPT-I alpha. In addition some aspects of CPT-I alpha expression are confined to the liver. The data presented here thus suggest that two types of differential regulation of CPT-I genes exist: (a) differential control of CPT-I alpha and CPT-I beta gene expression in the heart and (b) differential regulation of CPT-I alpha expression in the heart and liver.