Search PubMed⌕ Search

Biomedical subjects

T B Henriksen

Publications and source records attributed to T B Henriksen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Epilepsy and pregnancy: effect of antiepileptic drugs and lifestyle on birthweight.

OBJECTIVE: To investigate the impact of epilepsy and antiepileptic drugs on length of gestation and anthropometric measures of the newborn. DESIGN: Cohort study based on questionnaires mailed to all pregnant women who attended for prenatal care at our department from August 1989 to January 1997. SETTING: Department of Obstetrics and Gynaecology at Aarhus University Hospital, Denmark. PARTICIPANTS: One hundred and ninety-three singleton pregnancies in women with epilepsy were compared with 24,094 singleton pregnancies in women without epilepsy. MAIN OUTCOME MEASURES: Preterm delivery, small for gestational age, mean gestational age, gestational age-adjusted birthweight, head circumference, and body length. RESULTS: Children of women with epilepsy who smoked had lower gestational age and were at increased risk of preterm delivery (OR 3.4; 95% CI 1.8-6.5), compared with children born by nonepileptic women who smoked. Birthweight adjusted for gestational age was reduced by 102 g (95% CI 40-164) in women with epilepsy, and the risk of delivering a child who was small for gestational age was increased (adjusted OR 1.9, 95% CI 1.3-2.7), compared with women without epilepsy. Newborn babies of women with epilepsy treated by drugs had a reduced adjusted birthweight (208 g, 95% CI 116-300), head circumference (0.4 cm, 95% CI 0.0-0.7), and body length (0.5 cm, 95% CI 0.1-1.0), compared with the newborn infants of women without epilepsy. CONCLUSIONS: Women with epilepsy who smoked were at increased risk of preterm delivery compared with healthy smokers. Children of women with drug treated epilepsy had lower birthweight, length, and head circumference than children of women without epilepsy.

Adolescent↗
PubMed2000

A prospective study of smoking during pregnancy and SIDS.

AIMS: To study the association between smoking during pregnancy and sudden infant death syndrome (SIDS) using prospectively collected data, making it possible to account for a number of potential confounders. DESIGN: Prospective follow up study (n = 24 986). RESULTS: The overall rate of SIDS was 0.80 per 1000 live births (n = 20). Children of smokers had more than three times the risk of SIDS compared with children of non-smokers (OR = 3.5; 95% CI 1.4-8.7), and the risk of SIDS increased with the number of cigarettes smoked per day (p < 0.05). Adjustment for parity, alcohol, and caffeine intake during pregnancy, maternal height and weight before pregnancy, years of school, occupational status, marital status, and number of antenatal care visits did not change the results. Adjustment for mother's age marginally reduced the risk of SIDS associated with smoking (OR = 3.0; 95% CI 1.2-7.3). CONCLUSIONS: Given the prospective nature of the study, the number of deaths is small; however, if our results reflect a true association between smoking during pregnancy and SIDS, approximately 30-40% of all cases of SIDS could be avoided if all pregnant women stopped smoking in a population with 30% pregnant smokers. Our study adds to earlier evidence for an association between smoking during pregnancy and SIDS. The strengths of the study are the possibility to adjust for a number of potential confounders and the fact that information about smoking habits during pregnancy was prospectively collected.

Adolescent↗
PubMed2000

Fetal growth and infantile colic.

AIM: To describe how fetal growth and gestational age affect infantile colic, while considering other potential risk factors. STUDY DESIGN: A population based follow up study of 2035 healthy singleton infants without any disability born to Danish mothers. Information was collected by self administered questionnaires at 16 and 30 weeks of gestation, at delivery, and 8 months post partum. Infantile colic is defined according to Wessel's criteria, but symptoms are restricted to crying for more than three hours a day, for more than three days a week, and for more than three weeks. RESULTS: The cumulated incidence of infantile colic was 10.9%. Low birth weight babies (< 2500 g) had more than twice the risk (odds ratio = 2.7, 95% confidence interval 1.2 to 6.1) of infantile colic when controlled for gestational age, maternal height, and smoking. CONCLUSION: Low birth weight may be associated with infantile colic, and further research will be aimed to focus on fetal growth and infantile colic.

Analysis of Variance↗
PubMed2000

Male-mediated spontaneous abortion among spouses of stainless steel welders.

OBJECTIVES: Male-mediated spontaneous abortion has never been documented for humans. The welding of stainless steel is associated with the pulmonary absorption of hexavalent chromium, which has genotoxic effects on germ cells in rodents. Clinical and early subclinical spontaneous abortions were examined among spouses of stainless-steel welders. METHODS: A cohort of first-pregnancy planners was recruited from members of the union of metal workers and 3 other trade unions. The cohort was followed for 6 menstrual cycles from the cessation of contraceptive use. Altogether, 280 pregnancies were conceived, of which 35 were detected by human chorionic gonadotrophic hormone analysis and did not survive to a clinically recognized pregnancy. Information on exposure was collected prospectively in relation to the outcome and was available for all cycles resulting in a pregnancy. Information on pregnancy outcome was collected for all 245 clinically recognized pregnancies. RESULTS: Increased risk of spontaneous abortion was found for pregnancies with exposure to paternal stainless-steel welding (adjusted relative risk 3.5, 95% confidence interval 1.3-9.1). The results were consistent in analyses of both biochemically and clinically recognized abortions. There was no increased risk for spontaneous abortion in pregnancies with paternal exposure to the welding of metals other than stainless steel. CONCLUSIONS: Male welding of stainless steel was associated with an increased risk of spontaneous abortion in spouses. A mutagenic effect of hexavalent chromium has been found previously in both somatic and germ cells, and the findings could be due to mutations in the male genome.

Abortion, Spontaneous↗
PubMed1999

[Semen quality and fertility in a population-based follow-up study].

Little is known about the importance of semen quality in male infertility. We followed 430 first pregnancy planners with no previous reproductive experience recruited among more than 50,000 cohabiting trade-union members. The couples were consecutively enrolled into the study as they discontinued contraception and were followed up for six month menstrual cycles or until a pregnancy was verified. Each man provided a semen sample at enrollment. Women kept daily record of vaginal bleeding and sexual activity. The probability of conception increased with increasing sperm concentration up to 40 x 10(6)/ml, but any higher sperm density was not associated with additional likelihood of pregnancy. The proportion of sperm with normal morphology was strongly related to likelihood of pregnancy, independently of sperm concentration. In conclusion, sperm concentration and morphology are valuable biological markers of male fecundity. Reference values for semen quality based on biological knowledge can be established.

Biomarkers↗
PubMed1999

Menstrual cycle pattern and fertility: a prospective follow-up study of pregnancy and early embryonal loss in 295 couples who were planning their first pregnancy.

OBJECTIVE: To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss. DESIGN: Prospective follow-up study. SETTING: Healthy couples recruited throughout Denmark. PATIENT(S): Two hundred ninety-five couples who were planning their first pregnancy were followed up from the discontinuation of birth control until a pregnancy was recognized within six menstrual cycles. Early embryonal losses were detected by changes in urinary hCG levels. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The probability of pregnancy occurring within one menstrual cycle (fecundity). RESULT(S): In women who had a cycle length that differed by >10 days from the usual cycle length, fecundity was approximately 25% that of women who had no variation (odds ratio 0.25, 95% confidence interval 0.09-0.68). When the combined effect of cycle variation and cycle length was assessed, cycle variation was a persistent strong predictor of fecundity. CONCLUSION(S): The mechanisms of the present findings probably are female functional disturbances in ovulation, conception, implantation, or sustained pregnancy, linked with variable menstrual cycle length. Thus, identification of medical and environmental causes of abnormal menstrual cycle patterns may provide clues to the causes of infertility. Moreover, the menstrual cycle pattern also should be taken into consideration in the clinical decision-making process.

Abortion, Spontaneous↗
PubMed1999

Distress and reduced fertility: a follow-up study of first-pregnancy planners.

OBJECTIVE: To assess the effect of psychological distress on time to first pregnancy. DESIGN: A follow-up study of time to pregnancy with prospective data on distress, with controlling for potential confounding variables. SETTING: Two university hospitals. PATIENT(S): Danish couples (n = 430) who were planning their first pregnancy and had no previous reproductive experience were followed for six menstrual cycles. Psychological distress was measured in each menstrual cycle by the General Health Questionnaire. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): A clinically recognized pregnancy or a biochemical pregnancy detected in urine samples from each period of vaginal bleeding. RESULT(S): For cycles with the highest distress score (General Health Questionnaire score >80th percentile), the probability of conception per cycle was 12.8%, compared with 16.5% in other cycles (adjusted odds ratio [OR] 0.6; 95% confidence interval [CI] 0.4-1.0). The effect of distress was found almost exclusively among women with long menstrual cycles (OR 0.1; 95% CI 0.01-0.4 and OR 0.9; 95% CI 0.5-1.4 for women with cycles of > or =35 and <35 days, respectively). An increased incidence of early embryonal loss was also found among highly distressed women with long cycles, but was based on a small number of observations. CONCLUSION(S): Psychological distress may be a risk factor for reduced fertility in women with long menstrual cycles.

Abortion, Spontaneous↗
PubMed1999

Duration of breastfeeding and developmental milestones during the latter half of infancy.

Several studies have suggested that breastfeeding has a long-term influence on brain development. However, interpretation of these findings is complicated by the presence of many potential confounding factors. Only a few studies have examined infants before 1 y of age, although very early assessment might reduce the role of environmental influence. We investigated the association between exclusive breastfeeding and three developmental milestones related to general and fine motor skills and early language development at the age of 8 mo. We followed 1656 healthy, singleton, term infants, with a birthweight of at least 2500 g, born between May 1991 and February 1992 in Aarhus, Denmark. Information was collected at 16 wk gestation, at delivery and when the infant was 8 mo old. Motor skills were evaluated by measurement of crawling and pincer grip. Early language development was defined as the ability to babble in polysyllables. The proportion of infants who mastered the specific milestones increased consistently with increasing duration of breastfeeding. The relative risk for the highest versus the lowest breastfeeding category was 1.3 (95% CI: 1.0-1.6) for crawling, 1.2 (95% CI: 1.1-1.3) for pincer grip and 1.5 (95% Cl: 1.3-1.8) for polysyllable babbling. Little change was found after adjustment for confounding. In conclusion, our data support the hypothesis that breastfeeding benefits neurodevelopment.

Breast Feeding↗
PubMed1999

Is glycosylated haemoglobin a marker of fertility? A follow-up study of first-pregnancy planners.

We performed a follow-up study of time to pregnancy in a population of first-time pregnancy planners without previous reproductive experience. The objective of this paper is to report and discuss a finding of a strong relationship between glycosylated haemoglobin (HbA1C) and fertility. A total of 165 Danish couples without previous reproductive experience was followed from termination of birth control until pregnancy for a maximum of six menstrual cycles. HbA1C and reproductive hormones were measured at entry. Questionnaire data were collected at entry and once in each cycle during follow-up. The odds ratio (OR) for pregnancy per cycle decreased with increasing concentration of HbA1C (OR per percent HbA1C 0.4, 95% CI 0.2-0.9 for all six cycles and 0.2, 95% CI 0.1-0.5 in the first three cycles). A high concentration of HbA1C was associated with a high concentration of testosterone and a low concentration of inhibin A. No association was found between HbA1C and psychosocial distress. The reduced fertility among women with high HbA1C may be due to an association with subclinical polycystic ovaries as indicated by the hormonal profile.

Adult↗
PubMed1999

Preterm birth and intra-uterine growth retardation among children of women with schizophrenia.

BACKGROUND: There is conflicting evidence about the frequency of adverse pregnancy outcomes among women with schizophrenia. AIMS: To investigate the risk of preterm birth, low birth weight and intra-uterine growth retardation among women with schizophrenia. METHOD: A total of 2212 births to 1537 women with schizophrenia in Denmark were compared with a random sample of all deliveries in Denmark in 1973-1993 (122,931 births to 72,742 women). RESULTS: The children of women with schizophrenia were at increased risk of preterm delivery (relative risk = 1.46, 95% CI = 1.19-1.79), low birth weight (relative risk = 1.57, 95% CI = 1.36-1.82) and small for gestational age (relative risk = 1.34, 95% CI = 1.17-1.53). CONCLUSIONS: Women with schizophrenia are at increased risk of adverse pregnancy outcome. This may be associated with an increased mortality and general morbidity and risk of schizophrenia in their children.

Adult↗
PubMed1999

Smoking during pregnancy and hospitalization of the child.

OBJECTIVES: To study the association between smoking during pregnancy and hospitalization of the child before 8 months of age. DESIGN: A follow-up study of 1974 children born in 1991 and 1992. RESULTS: Overall, 158 (8%) of the children were hospitalized during the first 8 months of life. Compared with children whose mothers did not smoke during pregnancy, children with mothers who smoked 1 to 14 cigarettes per day had no increased risk of being hospitalized (relative risk: 1.1; 95% confidence interval: 0.8-1.5), whereas children whose mothers smoked 15 or more cigarettes per day had twice as high a risk of being hospitalized (relative risk: 2.0; 95% confidence interval: 1.2-3.3). When only hospitalizations before 2 months of age were analyzed, smoking during pregnancy was associated an increased risk similar to that described above. Hospitalization of the child was independent of the smoking habits of the father, and an increased risk of hospitalization associated with smoking was found not only among children with symptoms from the respiratory system but also among children with symptoms from the gastrointestinal system and the skin. The association between smoking during pregancy and hospitalization of the child persisted after adjustment for postpartum smoking habits and a number of socio-demographic and lifestyle factors. CONCLUSIONS: Smoking 15 or more cigarettes per day during pregnancy influenced the health of the children, and several points indicated that the effect of in utero exposure was independent of postpartum smoking habits. If all pregnant women smoking 15 or more cigarettes per day stopped smoking, approximately 5% of all admissions to hospitals before 8 months of age could be avoided. smoking during pregnancy, hospitalization of children.

Female↗
PubMed1998

Adult and prenatal exposures to tobacco smoke as risk indicators of fertility among 430 Danish couples.

During 1992-1995, 430 Danish couples were recruited after a nationwide mailing of a letter to 52,255 trade union members who were 20-35 years old, lived with a partner, and had no children. The couples were enrolled into the study when they discontinued birth control, and they were followed for six menstrual cycles or until a clinically recognized pregnancy. At enrollment and each month throughout the follow-up, both partners completed a questionnaire that asked them about their smoking, alcohol consumption, and intake of caffeinated beverages. The effect of current smoking and smoking exposure in utero was evaluated by using a logistic regression model with pregnancy outcome of each cycle in a Cox discrete model calculating the fecundability odds ratio. After adjustment for female body mass index and alcohol intake, diseases in female reproductive organs, semen quality, and duration of menstrual cycle, the fecundability odds ratio for smoking women exposed in utero was 0.53 (95% confidence interval (CI) 0.31-0.91) compared with unexposed nonsmokers. Fecundability odds ratio for nonsmoking women exposed in utero was 0.70 (95% CI 0.48-1.03) and that for female smokers not exposed in utero was 0.67 (95% CI 0.42-1.06). Exposure in utero was also associated with a decreased fecundability odds ratio in males (0.68, 95% CI 0.48-0.97), whereas present smoking did not reduce fecundability significantly. It seems advisable to encourage smoking cessation prior to the attempt to conceive as well as during pregnancy.

Adolescent↗
PubMed1998

Relation between semen quality and fertility: a population-based study of 430 first-pregnancy planners.

BACKGROUND: Semen analysis is part of the routine assessment of infertile couples. WHO defines a sperm concentration above 20x10(6) per mL seminal fluid as normal. We studied the association between semen quality and the probability of conception in a single menstrual cycle in Danish couples with no previous reproductive experience. METHODS: In 1992-94, we invited 52,255 trades-union members aged 20-35 years, who lived with a partner and had no children to take part in the study; 430 couples agreed. The couples discontinued use of contraception, and were followed up for six menstrual cycles or until a pregnancy was verified within this period. Each man was asked to provide a semen sample at enrolment (which was analysed without freezing). Women kept a daily record of vaginal bleeding and sexual activity. The association between semen quality and likelihood of pregnancy was assessed by logistic regression, adjusted for sexual activity and female factors associated with low fertility. RESULTS: There were 256 (59.5%) pregnancies among the 430 couples: 165 (65.0%) among those with a sperm concentration of 40x10(6)/mL or more and 84 (51.2%) among those with lower sperm concentrations. The probability of conception increased with increasing sperm concentration up to 40x10(6)/mL, but any higher sperm density was not associated with additional likelihood of pregnancy. The proportion of sperm with normal morphology was strongly related to likelihood of pregnancy independently of sperm concentration. Semen volume and motility were of limited value in pregnancy prediction. INTERPRETATION: Our study suggests that the current WHO guidelines for normal semen quality should be used with caution. Some men with sperm counts above the lower limit of the normal range defined by WHO may in fact be subfertile.

Adult↗
PubMed1998

Does moderate alcohol consumption affect fertility? Follow up study among couples planning first pregnancy.

OBJECTIVE: To examine the effect of alcohol consumption on the probability of conception. DESIGN: A follow up study over six menstrual cycles or until a clinically recognised pregnancy occurred after discontinuation of contraception. SUBJECTS: 430 Danish couples aged 20-35 years trying to conceive for the first time. MAIN OUTCOME MEASURES: Clinically recognised pregnancy. Fecundability odds ratio: odds of conception among exposed couples divided by odds among those not exposed. RESULTS: In the six cycles of follow up 64% (179) of women with a weekly alcohol intake of less than five drinks and 55% (75) of women with a higher intake conceived. After adjustment for cycle number, smoking in either partner or smoking exposure in utero, centre of enrolment, diseases in female reproductive organs, woman's body mass index, sperm concentration, and duration of menstrual cycle, the odds ratio decreased with increasing alcohol intake from 0.61 (95% confidence interval 0.40 to 0.93) among women consuming 1-5 drinks a week to 0.34 (0.22 to 0.52) among women consuming more than 10 drinks a week (P=0.03 for trend) compared with women with no alcohol intake. Among men no dose-response association was found after control for confounders including women's alcohol intake. CONCLUSION: A woman's alcohol intake is associated with decreased fecundability even among women with a weekly alcohol intake corresponding to five or fewer drinks. This finding needs further corroboration, but it seems reasonable to encourage women to avoid intake of alcohol when they are trying to become pregnant.

Adult↗
PubMed1998

[Smoking during pregnancy and preterm delivery].

The purpose of the study was to evaluate the association between smoking during pregnancy and preterm birth. The overall rate of preterm delivery was 4.3%. Smokers had a 40% higher risk of preterm birth compared to non-smokers. A dose response relationship was found between smoking and risk of preterm birth. Adjustment for women's height, pre-pregnant weight, age of the mother, marital status, education, occupational status, and alcohol intake did not change the results. Among women with an intake of less than 400 mg of caffeine per day no difference in the risk of preterm birth between smokers and non-smokers was found. However, among women with an intake of more than 400 mg of caffeine per day, the risk of preterm birth was increased almost threefold among smokers compared to non-smokers. Furthermore, among women with a high intake of caffeine a dose response relationship was found between smoking and risk of preterm delivery.

Adolescent↗
PubMed1998

A prospective intervention study of stopping smoking in pregnancy in a routine antenatal care setting.

OBJECTIVES: To evaluate the effect of specific education of midwives on stopping smoking in pregnant women and to determine the effect of this programme on pregnancy outcome. DESIGN: A prospective intervention study. SETTING: Department of Gynaecology and Obstetrics, Aarhus University Hospital, Denmark. POPULATION AND METHODS: A group of midwives (9 out of 54) was taught the effects of smoking during pregnancy and instructed in various methods of educating women to stop smoking. All pregnant women who attended antenatal care from October 1994 to September 1995 were either in the intervention group (n = 527) or the control group (n = 2629). Pregnant women attending the specifically educated midwives were considered to be the intervention group. They were given individual advice about stopping smoking at the first antenatal visit at about 16 weeks of gestation and a leaflet on smoking and pregnancy. RESULTS: At the first antenatal visit at about 16 weeks of gestation, 22% of the pregnant women smoked. Between the first visit and the routine visit at 30 weeks of gestation 51 (2%) stopped smoking and 56 (2%) started smoking. No differences were found between the intervention group and the control group in the rate of stopping smoking, validated by cotinine measurements. Mean birthweight, mean gestational age and the proportion of preterm birth in the two groups were similar. CONCLUSION: Education of midwives and integration of advice about smoking cessation at a low cost in routine antenatal care failed to affect smoking habits among pregnant women.

Adolescent↗