Population-based Pregnancy Cohort Study Research Articles

Abnormally Invasive Placenta—Prevalence, Risk Factors and Antenatal Suspicion: Results From a Large Population-based Pregnancy Cohort Study in the Nordic Countries

(BJOG. 2016;123:1348–1355) An abnormally invasive placenta (AIP), caused by abnormal invasion of the chorionic villi into the myometrium, presents a significant risk of hemorrhage, peripartum hysterectomy, and other complications. It has been reported to occur in 2 to 90 per 10,000 births. Risk factors include placenta previa, prior cesarean section (CS) especially in combination with placenta previa, and increasing maternal age and parity. Fewer complications have been observed when a planned operative delivery is undertaken in patients with AIP. Therefore, antenatal suspicion of AIP is important in the management of these patients. This study aimed to assess prevalence, risk factors, risk groups and antenatal suspicion of AIP as part of the Nordic Obstetric Surveillance Study.

History of depression and risk of hyperemesis gravidarum: a population-based cohort study

Hyperemesis gravidarum (HG) is a pregnancy condition characterised by debilitating nausea and vomiting. HG has been associated with depression during pregnancy but the direction of the association remains unclear. The aim of this study was to assess whether previous depression is associated with HG. This is a population-based pregnancy cohort study using data from The Norwegian Mother and Child Cohort Study. The study reviewed 731 pregnancies with HG and 81,055 pregnancies without. Logistic regression analyses were performed to examine the association between a lifetime history of depression and hyperemesis gravidarum. Odds ratios were adjusted for symptoms of current depression, maternal age, parity, body mass index, smoking, sex of the child, education and pelvic girdle pain. A lifetime history of depression was associated with higher odds for hyperemesis gravidarum (aOR = 1.49, 95% CI (1.23; 1.79)). Two thirds of women with hyperemesis gravidarum had neither a history of depression nor symptoms of current depression, and 1.2% of women with a history of depression developed HG. A lifetime history of depression increased the risk of HG. However, given the fact that only 1.2% of women with a history of depression developed HG and that the majority of women with HG had no symptoms of depression, depression does not seem to be a main driver in the aetiology of HG.

Prenatal exposure to antidepressants and language competence at age three: results from a large population-based pregnancy cohort in Norway.

To examine the association between maternal use of selective serotonin reuptake inhibitors (SSRI) in pregnancy and language competence in their children at age three taking into account maternal symptoms of anxiety and depression. Population-based prospective pregnancy cohort study. The Norwegian Mother and Child Cohort Study; recruited pregnant women from 1999 through 2008. 45,266 women with 51,748 singleton pregnancies. The association between short- or long-term use of SSRI during pregnancy and language competence in the child was investigated using multinomial logistic regression with three outcome categories: long, complicated sentences, fairly complete sentences and language delay. Children's language competence at age three measured by maternal report on a validated language grammar scale. Women reported use of SSRI in 386 (0.7%) pregnancies. Of these, 161 (42%) reported long-term use. Compared with children whose mothers took no SSRI, using the best language category as the reference, adjusted relative risk ratios (RRR) of having fairly complete sentences were 1.21 (95% CI 0.85-1.72) and 2.28 (1.54-3.38) for short- and long-term SSRI use, respectively. The adjusted RRRs of language delay were 0.86 (0.42-1.76) and 2.30 (1.21-4.37). Symptoms of anxiety and depression in pregnancy were independently related to language delay, adjusted RRR 1.25 (1.03-1.50) and 1.83 (1.40-2.40) for short- and long-term symptoms, respectively. Prolonged use of SSRI during pregnancy was associated with lower language competence in children by age three independently of depression. Having symptoms of depression throughout pregnancy had an independent effect.

The associations between maternal pre-pregnancy body mass index or gestational weight change during pregnancy and body mass index of the child at 3 years of age

To estimate the associations between maternal pre-pregnancy body mass index (BMI) or gestational weight change (GWC) during pregnancy and offspring BMI at 3 years of age, while taking several pre-and postnatal factors into account. The Norwegian Mother and Child Cohort Study is a population-based pregnancy cohort study of women recruited from all geographical areas of Norway. The study includes 31 169 women enrolled between 2000 and 2009 through a postal invitation sent to women at 17-18 weeks of gestation. Data collected from 5898 of the fathers were included. MAIN OUTCOME MESURES: Offspring BMI at 3 years was the main outcome measured in this study. Mean maternal pre-pregnancy BMI was 24.0 kg m(-2) (s.d. 4.1), mean GWC in the first 30 weeks of gestation was 9.0 kg (s.d. 4.1) and mean offspring BMI at 3 years of age was 16.1 kg m(-2) (s.d. 1.5). Both maternal pre-pregnancy BMI and GWC were positively associated with mean offspring BMI at 3 years of age. Pre-pregnancy BMI and GWC also interacted, and the strength of the interaction between these two factors was strongly associated with the increase in offspring BMI among mothers who gained the most weight during pregnancy and had the highest pre-pregnancy BMI. Our findings show that results could be biased by not including pre-pregnant paternal BMI. This large population-based study showed that both maternal pre-pregnancy BMI and GWC were positively associated with mean offspring BMI at 3 years of age.

Maternal pre‐pregnant body mass index, maternal weight change and offspring birthweight

To estimate the association between maternal pre-pregnant body mass index (BMI) and maternal weight change during pregnancy and offspring birthweight using the BMI classification developed by World Health Organization (WHO) and adopted by the Institute of Medicine (IOM) in 2009. The Norwegian Mother and Child Cohort Study (MoBa) is a population-based pregnancy cohort study conducted by The Norwegian Institute of Public Health. Women were recruited from all geographic areas of Norway. The study includes 58,383 pregnant women. Women were enrolled in 2000-2007 by a postal invitation offered to women in Norway at 17-18 weeks of gestation. Linear regression analyses are based on exposure data from two questionnaires during pregnancy and on birthweight data. Birthweight. Mean pre-pregnancy BMI was 24kg/m(2) (SD 4.3), mean maternal weight change in the first 30 weeks of gestation was 9.3kg (SD 4.4), mean birthweight was 3675g (SD 487) and mean age 30.3 years. Of the women, 65.2% had a normal pre-pregnancy weight, 2.9% were underweight, 22.3% overweight, and 9.5% obese (Classes 1-3). Linear regression analyses adjusted for potential confounders showed that offspring birthweight increased with increasing maternal pre-pregnant BMI, and with increasing maternal weight gain during pregnancy in all six categories of pre-pregnancy BMI. Women with the highest level of education had the highest offspring birthweight. Offspring birthweight increased with both increasing maternal pre-pregnant BMI and maternal weight gain during pregnancy in all six categories of maternal pre-pregnancy BMI.

Effect of dietary factors in pregnancy on risk of pregnancy complications: results from the Norwegian Mother and Child Cohort Study

There has been a thrilling development , as well as profound changes, in our understanding of the effect of fetal nutrition on the development and health of the child. The Norwegian Mother and Child Cohort Study (MoBa) is an ongoing nationwide population-based pregnancy cohort study that between 1999 and 2008 recruited 90,723 women with 106,981 pregnancies and 108,487 children. The objective of MoBa is to test specific etiologic hypotheses by estimating the association between exposures and diseases with a special focus on disorders that may originate in early life. An important aspect in this regard is maternal diet and nutritional status during pregnancy. Nutritional factors have long been considered to be important determinants of maternal and fetal health, and dietary information is currently being collected in a number of pregnancy cohorts in Europe and the United States. Thus far, pregnancy complications studied in MoBa are preterm birth, preeclampsia, and fetal growth; and the aim of this article is to report results of recently published studies of dietary factors in relation to these outcomes. Numerous studies are planned using MoBa data, and the aim is to add to the knowledge of the interplay between dietary factors, nonnutrients, and toxic dietary substances and epigenetic modulation on fetal development and health later in life.

Risk Factors for Full- and Partial-Syndrome Early Adolescent Eating Disorders: A Population-Based Pregnancy Cohort Study

ObjectiveTo identify prospective predictors of eating disorders in a population-based sample of 14-year-old boys and girls, using previously collected antenatal, biomedical, familial, demographic, and psychosocial data. MethodParticipants (N = 1,597) were drawn from the Western Australian Pregnancy Cohort (Raine) Study. Data were collected during pregnancy, at birth, and when children were aged 1, 2, 5, 8, 10, and 14 years. An adapted version of the Eating Disorder Examination Questionnaire was used to assess eating disorder symptoms at age 14 years. Logistic regression was used to identify prospective predictors of eating disorder caseness, relative to general control and psychiatric control groups. ResultsAt age 14 years, 6% of the sample met full or partial criteria for a DSM-IV eating disorder. Being female and being perceived as overweight by one's parent were the strongest predictors of eating disorder caseness in the final multivariate models, relative to both control groups. Maternal body mass index, social problems, low social-related self-efficacy, and neurocognitive difficulties were also predictive of eating disorder caseness relative to the general control group only. ConclusionsThe results suggest that parent's perceptions of their child's weight are more powerful than objective child body weight in predicting the development of eating disorders. Parent-perceived child overweight was also a specific risk factor for eating disorders, whereas elevated maternal weight and childhood psychosocial difficulties seem to be associated with increased risk for psychiatric disturbance more generally. These results have implications for the prevention of eating disorders, particularly in light of recent increases in the prevalence of childhood obesity.