Pregnancy

About: Pregnancy is a research topic. Over the lifetime, 163969 publications have been published within this topic receiving 4013502 citations. The topic is also known as: pregnancy & gestation.

Differences in teenage pregnancy rates among five developed countries: the roles of sexual activity and contraceptive use.

Abstract: CONTEXT: Adolescent pregnancy, birth, abortion and sexually transmitted disease (STD) rates are much higher in the United States than in most other developed countries. METHODS: Government statistics or nationally representative survey data were supplemented with data collected by private organizations or for regional or local populations to conduct studies of adolescent births, abortions, sexual activity and contraceptive use in Canada, the United States, Sweden, France and Great Britain. RESULTS: Adolescent childbearing is more common in the United States (22% of women reported having had a child before age 20) than in Great Britain (15%), Canada (11%), France (6%) and Sweden (4%); differences are even greater for births to younger teenagers. A lower proportion of teenage pregnancies are resolved through abortion in the United States than in the other countries; however, because of their high pregnancy rate, U.S. teenagers have the highest abortion rate. The age of sexual debut varies little across countries, yet American teenagers are the most likely to have multiple partners. A greater proportion of U.S. women reported no contraceptive use at either first or recent intercourse (25% and 20%, respectively) than reported nonuse in France (11% and 12%, respectively), Great Britain (21% and 4%, respectively) and Sweden (22% and 7%, respectively). CONCLUSIONS: Data on contraceptive use are more important than data on sexual activity in explaining variation in levels of adolescent pregnancy and childbearing among the five developed countries; however, the higher level of multiple sexual partnership among American teenagers may help explain their higher STD rates.

Maternal Smoking During Pregnancy and Psychiatric Adjustment in Late Adolescence

Abstract: Background This study assessed the extent to which exposure to maternal smoking during pregnancy was associated with increased risks of psychiatric symptoms in late adolescence (adolescents aged 16-18 years) when due allowance was made for confounding or selection factors associated with maternal smoking during pregnancy. Methods Data were gathered during an 18-year longitudinal study of a birth cohort of 1265 children born in New Zealand. The measures collected included (1) maternal smoking during pregnancy; (2) assessments of psychiatric problems (conduct disorder, major depression, and anxiety and substance use disorders) at age 16 to 18 years; and (3) measures of potentially confounding social, family, and parental factors. Results Children exposed to maternal smoking during pregnancy had higher psychiatric symptom rates for conduct disorder, alcohol abuse, substance abuse, and depression. Those children whose mothers smoked at least 1 pack of cigarettes per day during their pregnancy had symptom rates that were between 1.4 and 2.5 (median, 2.0) times higher than the children of nonsmokers. Smoking during pregnancy was also associated with a series of adverse or disadvantageous factors that included (1) socioeconomic disadvantage, (2) impaired child-rearing behaviors, and (3) parental and family problems. After adjustment for these confounding and selection factors, smoking during pregnancy was significantly associated with an increased rate of conduct disorder symptoms in late adolescence ( P Conclusions This study suggests that maternal smoking during pregnancy may contribute to childrens' risk of later externalizing problems. There is a need to further explore the moderating effect of the sex of the child and to clarify the underlying pathophysiological features of this relationship.

Is There a Causal Relationship between Iron Deficiency or Iron-Deficiency Anemia and Weight at Birth, Length of Gestation and Perinatal Mortality?

Abstract: An extensive literature review was conducted to identify whether iron deficiency, iron-deficiency anemia and anemia from any cause are causally related to low birth weight, preterm birth or perinatal mortality. Strong evidence exists for an association between maternal hemoglobin concentration and birth weight as well as between maternal hemoglobin concentration and preterm birth. It was not possible to determine how much of this association is attributable to iron-deficiency anemia in particular. Minimal values for both low birth weight and preterm birth occurred at maternal hemoglobin concentrations below the current cut-off value for anemia during pregnancy (110 g/L) in a number of studies, particularly those in which maternal hemoglobin values were not controlled for the duration of gestation. Supplementation of anemic or nonanemic pregnant women with iron, folic acid or both does not appear to increase either birth weight or the duration of gestation. However, these studies must be interpreted cautiously because most are subject to a bias toward false-negative findings. Thus, although there may be other reasons to offer women supplemental iron during pregnancy, the currently available evidence from studies with designs appropriate to establish a causal relationship is insufficient to support or reject this practice for the specific purposes of raising birth weight or lowering the rate of preterm birth.