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Low birth weight in pregnancies following induced abortion: no evidence for an association.

Compared with women delivering a first pregnancy, those delivering a second pregnancy after aborting the first have similar rates of low (less than 2,500 g) birth weight newborns (relative risk (RR) G2A1/G1 = 0.86, 95% confidence interval (CI) = 0.49-1.51) and mean birth weight (delta = 16.3 g, p = 0.63). Abortion of the first pregnancy prevents the reduction in low birth weight and increase in mean birth weight in the second pregnancy which delivery of the first pregnancy normally bestows (RR G2P1/G2A1 = 0.48, 95% CI = 0.25-0.90; delta = 135.3 g, p less than 0.0001). Two prior induced abortions do not significantly increase risk for low birth weight (RR G3A2/G1 = 1.14, 95% CI = 0.37-3.56) or decrease mean birth weight (delta = 29.0 g), compared with women delivering their first pregnancy. The second of two deliveries has a reduced risk of low birth weight irrespective of whether both deliveries follow an aborted first pregnancy. Adjustment for confounding factors did not materially change these results. Low birth weight rates were higher after abortions performed in hospital compared with elsewhere (p = 0.03), but mean birth weight was not affected. Gestation at abortion, vacuum aspiration or dilatation and curettage, and abortion complications were unrelated to birth weight of subsequent pregnancies. Pregnancies conceived within six months of a prior abortion or delivery had lower birth weight than if the antecedent pregnancy ended more than six months previously.

Abortion, Induced↗

Obstacles to timely neonatal screening in North Thames.

OBJECTIVE: To assess the timeliness of neonatal (Guthrie card) screening in North Thames, and to identify the most effective ways of improving it. DESIGN: Analysis of information routinely collected in the course of neonatal screening; reanalysis of published data on blood phenylalanine concentration in phenylketonuria (PKU) over the first two weeks; simulation studies on the impact of different interventions. SUBJECTS: 100,690 infants born over one year and screened at Great Ormond Street Hospital NHS Trust. OUTCOME MEASURE: Interval between birth and reading PKU screen results. RESULTS: Although 75% of samples (district range 55-91%) were collected by day 7, only 81% had arrived in the laboratory seven days later (range 57-96%). The average interval between birth and reading results was 14.5 days, with only 9.7% read by day 10. Samples could be collected from day 4 without significant impact on false negative rates for PKU. If samples were collected from day 4 and posted promptly (second class), the average interval between birth and reading results could be reduced to 9.3 days. If first class mail were used and the laboratory operated on Saturdays, and used assays that could be read the same day rather than bacterial inhibition assays, the average would be 7.8 days, with 96% read by day 10. CONCLUSION: Timeliness of neonatal screening shows unacceptable variation between districts, and delays in dispatch of specimens to the laboratory. Same day, first class posting should be introduced, and samples could be collected between days 4 and 8.

Blood Specimen Collection↗

Estimation of variance components for lamb weights in three sheep populations.

Variance components were estimated for lamb weight at birth, 50 d, and 100 d of age. Data from the Canadian flock recording program for lambs born in 1977 to 1991 for Hampshires (n = 6,395) and Polled Dorsets (n = 29,204) and 1982 to 1991 for Romanovs (n = 3,432) were studied. Observed weights were pre-adjusted for the effects of age of dam, sex of lamb, birth-rearing type, month or quarter of year of birth, parity-lambing interval, and age of dam at first lambing, using estimates derived from a fixed effects model including contemporary groups plus these factors. Pre-adjusting for nuisance variables reduced the number of equations in the model for variance component estimation. A single-trait animal model with derivative-free restricted maximum-likelihood procedures was used. Random effects were additive direct and maternal genetic, litter (common environmental), and error. An alternate model excluded maternal genetic effects. Estimates of litter variance as a proportion of phenotypic variance were of moderate size (.12 to .43) and consistent across breeds and models. The mean correlation between direct and maternal genetic effects, across traits and breeds, weighted by the number of animals, was -.40 (SE = .15). The maternal genetic variance or direct-maternal genetic covariance component, or both, was different from zero (P < .05) for all traits in Hampshires and Polled Dorsets, suggesting that maternal effects were important for weight of lambs even at 100 d of age. Estimates of direct heritability ranged from .05 to .45, varying across traits, breeds, and models.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Adverse reproductive outcomes among pregnancies of aunts and (spouses of) uncles in Irish families with neural tube defects.

Adverse pregnancy outcomes may be more frequent among sibs of individuals with neural tube defects (NTDs), and transmission of risk in families with an NTD may be more frequent among maternal relatives. In a study designed to evaluate matrilineal risk for NTDs, we compared adverse pregnancy outcomes among maternal and paternal first cousin pregnancies. Pregnancy histories were obtained by interview with 288 uncles and aunts (parents of the first cousin pregnancies) in 48 Irish NTD families. We analyzed pregnancy outcomes (preterm deliveries, stillbirths, and miscarriages) among 1,033 singleton first cousin pregnancies and compared risk among maternal versus paternal relatives. Maternal first cousin pregnancies were more likely to end adversely when compared to paternal first cousin pregnancies (17.4% vs. 11.7%, P = 0.01). In a logistic regression analysis of pregnancies unaffected by birth defects, maternal line remained independently associated with adverse outcomes (odds ratio (OR) = 1.55, 95% confidence interval (CI) 1.06, 2.27) after controlling for NTD type, maternal age, maternal smoking during pregnancy, first cousin pregnancy's year of birth. The excess risk with maternal line related mainly to spina bifida occulta families (OR = 42.4; CI 2.64, 681; P = 0.008); risk in open spina bifida families was 1.24 (CI 0.82, 1.87; P = 0.3). These results support the hypothesis of excess risk for adverse pregnancy outcomes among maternal relatives in NTD families. Further work is needed, epidemiological as well as clinical and molecular, not only to confirm these findings, but also to define the underlying biological mechanisms linking adverse reproductive outcomes, excess maternal risk and occurrence of NTDs.

Adult↗

Do higher status and more autonomous women have longer birth intervals? Results from Cebu, Philippines.

We look at whether women's status and autonomy affect birth-to-conception intervals using data from the Cebu Longitudinal Health and Nutrition Survey (CLHNS) in the Philippines. We followed 1123 married, fecund women, aged 25-49, for up to 5 years. In a 1994-1995 survey, women were asked about the timing of their last birth. In 1998-2000, women were asked about any pregnancies since the 1994-1995 survey. Using these two surveys, we calculated birth to conception intervals. Women were censored if they reached their 50th birthday during follow-up. We measure autonomy based on whether the wife has the final say in 10 household decisions as measured in the 1994-1995 survey. Using Cox proportional hazards models we find that women with more decision-making autonomy have significantly longer birth-to-conception intervals in unadjusted models. After adjustment for age, wealth, education, other socio-economic variables, and women's status, decision-making autonomy remained a significant predictor in all models. This effect remains even after adjusting for contraceptive use, implying that autonomy influences birth-to-conception intervals through other mechanisms above and beyond increased contraceptive use. Additionally, few of the women's status variables were significantly associated with time to next conception. Women who had their first birth later in life were more likely to conceive during the observation period suggesting that they may be having shorter birth intervals in order to "catch up" with their peers. Maternal and child health-care efforts can help women achieve their desired spacing goals by supporting women's autonomy-in addition to ensuring they have accurate information and a range of contraceptive options.

Adult↗

Retinopathy of prematurity-induced blindness: birth weight-specific survival and the new epidemic.

A recent population-based study in the Canadian province of British Columbia showed that, since the mid-1960s, there has been a significant increase in the incidence of retinopathy of prematurity-induced blindness in infants weighing 750 to 999 g at birth. To determine the impact of changing birth weight-specific survival on this new epidemic, all infants born in the province in the period 1952 through 1986 and known to the British Columbia Health Surveillance Registry as having retinopathy of prematurity-induced blindness were identified. In addition, the birth registration records for the 1,299 740 infants born in British Columbia in the same period and the death records of the 22,940 British Columbia-born infants who died in the province before the end of their first year of life were linked using a combination of probabilistic and manual record linkage techniques. These linked records and the records from the Health Surveillance Registry were used to calculate birth weight-specific incidence rates of retinopathy of prematurity-induced blindness in liveborn infants and first-year-of-life survivors. The rates, in 5-year intervals, showed that, in both liveborn infants and first-year survivors, the highest birth weight-specific rates occurred during the first epidemic of retinopathy of prematurity, which ended in British Columbia in 1954. Since the mid-to late-1960s, the incidence of retinopathy of prematurity-induced blindness in liveborn infants weighing less than 1000 g increased steadily whereas in infants weighting 1000 to 1499 g, incidence decreased slightly since the original epidemic ended. However, the experience of first-year-of-life survivors is substantially different.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗

Neurologic status and intracranial hemorrhage in very-low-birth-weight preterm infants. Outcome at 1 year and 5 years.

Twenty-six very-low-birth-weight preterm infants with and without intracranial hemorrhage (ICH) were followed up prospectively from birth to school age to determine the relationship between ICH and subsequent neurologic and cognitive outcomes. All children had sequential cranial ultrasound examinations at birth and neurologic assessments at 3-month intervals during the first year, at 1 year of age, and at 5 to 6 years; psychometric assessments were done at 5 to 6 years. Seventeen children had no ICH, 3 had grade 1 ICH, 1 had grade 3 ICH, and 5 had grade 4 ICH. The 1-year Amiel-Tison neurologic assessment in 25 infants demonstrated that 14 were normal, 3 were suspect, and 8 were abnormal. By 5 to 6 years of age, 5 of 8 children neurologically abnormal at 1 year remained abnormal, 2 of 3 children neurologically suspect at 1 year remained suspect; while 9 of 15 children neurologically normal at 1 year remained normal, the remaining 6 had become suspect. The predominant neurologic abnormality at 5 to 6 years was subtle neurologic dysfunctioning. The Wechsler Preschool and Primary Scale of Intelligence at 5 to 6 years revealed a mean group IQ score of 92.1. The Beery Visual Motor Integration Test results demonstrated that 18 of 26 children had mild to severe visual motor perceptual difficulties. Severe ICH (grades 3 and 4) correlated with abnormal neurologic performances at 1 and 5 to 6 years. Mild ICH (grade 1) and no ICH did not correlate with any one of the 1-year neurologic classifications. The 1-year status correlated with the 5- to 6-year neurologic outcome best for children who were either neurologically suspect or abnormal at age 1 year. The 1-year neurologic score did not correlate with 5- to 6-year IQ and Beery Visual Motor Integration Test scores.

Cerebral Hemorrhage↗

Signs of first-degree heart block occur in one-third of fetuses of pregnant women with anti-SSA/Ro 52-kd antibodies.

OBJECTIVE: To prospectively investigate the development of fetal heart block in anti-SSA/Ro 52-kd-positive women, and to evaluate the usefulness of serial Doppler echocardiography in detecting early signs of congenital heart block. METHODS: Twenty-four women with anti-SSA/Ro 52-kd antibodies and consequently increased risk for fetal heart block were followed up weekly, between 18 and 24 weeks of gestation, with two Doppler echocardiographic methods designed to estimate the time delay between hemodynamic events caused by atrial and ventricular depolarizations. Two hundred eighty-four women with normal pregnancies served as controls. Anti-Ro 52-kd, anti-Ro 60-kd, and anti-La antibodies were investigated by immunoblotting and enzyme-linked immunosorbent assay using recombinant proteins. RESULTS: In anti-Ro 52-kd-positive women, fetal atrioventricular (AV) time intervals were longer and heart rates were slightly lower compared with those in controls. Eight of 24 fetuses had signs of first-degree block. One of these fetuses had progression to complete block, and another showed recovery from second-degree block to first-degree block with betamethasone treatment. In the remaining 6 fetuses, spontaneous normalization occurred before or shortly after birth. Fetuses with normal AV time intervals at 18-24 weeks had normal electrocardiographic results at birth. CONCLUSION: Anti-Ro 52-kd-positive pregnant women frequently carry fetuses with Doppler echocardiographic signs of first-degree AV block. These blocks revert spontaneously in the majority of fetuses, but progression to a more severe degree of block may occur in some. Serial Doppler echocardiographic measurement of AV time intervals is suggested as a useful method for surveillance of these high-risk pregnancies.

Adult↗

Does breastfeeding protect against allergic rhinitis during childhood? A meta-analysis of prospective studies.

UNLABELLED: The effect of breastfeeding on the development of allergic rhinitis and other atopic conditions has been assessed in many studies but remains controversial. To elucidate this issue, a systematic review was conducted of prospective studies that evaluated the association between exclusive breastfeeding during the first 3 mo after birth and allergic rhinitis. The 1966-2000 MEDLINE databases were searched and the reference lists of relevant articles were reviewed according to predetermined inclusion criteria. The methodological aspects of each study, duration and exclusivity of breastfeeding, outcome measures, control for potential confounding variables and other factors were assessed, and estimates of the association between breastfeeding and allergic rhinitis were abstracted independently by the investigators using a standardized approach. Six prospective studies met the inclusion criteria. The summary odds ratio for the protective effect of breastfeeding was 0.74 (95% confidence interval 0.54-1.01). The effect estimate in studies of children with a family history of atopy was 0.87 (95% confidence interval 0.48-1.58). CONCLUSION: Exclusive breastfeeding during the first 3 mo after birth protects against allergic rhinitis in children, both with and without a family history of atopy. The protective association, although of borderline statistical significance, was substantial. Larger prospective studies with strict methodology and longer periods of follow-up are needed.

Age Distribution↗

Reproductive factors and extreme levels of maternal serum alpha-fetoprotein: a population-based study.

BACKGROUND: Levels of maternal alpha-fetoprotein (AFP) are increased during multiple gestations and preeclampsia but little is known regarding AFP levels in relation to other reproductive factors. Consequently, the objective of this work was to describe the possible relationship between AFP levels during pregnancy and maternal age at birth, maternal age at first birth, parity, time since previous birth and gender of the offspring. METHODS: Based on national registries we obtained the reproductive history on a population-based cohort of 44 227 women who had serum AFP levels determined in gestational weeks 14-21 and whose present and previous pregnancies resulted in live-born singletons. RESULTS: Many previous births and an interval of less than 2 years since last birth were significantly associated with extremely low levels of AFP in the mother. However, age at first birth and age at present pregnancy did not influence the AFP level. Women who gave birth to a girl had AFP levels that were 5%[95% confidence interval (CI) 4-6%] lower than those of women who had a boy. Adjustment for birthweight did not significantly affect the estimate. CONCLUSIONS: Low serum AFP levels in pregnancy are significantly correlated with high parity and with a short interval between births. The significantly lower levels of AFP in women who gave birth to girls could indicate a possible gender-specific regulatory mechanism.

Adolescent↗

Positive correlation between parity and incidence of thyroid cancer: new evidence based on complete Norwegian birth cohorts.

We have examined the effect of parity on the incidence of thyroid cancer within a hazard model framework, using individual data on all (1.1 million) Norwegian women born 1935-1969. This unique data source was established by linking information from the Cancer Registry with maternity histories derived from the Central Population Register of Norway. The relative effects on the total incidence of thyroid cancer, net of age, place of residence and birth cohort, are 1.00 for the childless (arbitrarily chosen baseline group), 1.13 for parity 1, 1.30 for parity 2, 1.39 for parity 3 and 1.46 for parity 4+. The latter 3 figures are significantly higher than 1.00. The effects are larger for follicular carcinoma, and for this type of thyroid cancer there are also indications of a recent-pregnancy effect. Among women with 2 or more children, those who became pregnant less than 45 months previously have a higher cancer incidence than others at the same parity. Moreover, we have found that parity has virtually the same effect at all ages, in all birth cohorts and in both parts of the country. Age at first birth as well as the length of the interbirth interval appear to be unrelated to the thyroid-cancer risk. Our findings are consistent with previous case-control studies from other countries.

Adolescent↗

Death of a husband or marital divorce related to risk of breast cancer in middle-aged women. A nested case-control study among Norwegian women born 1935-1954.

A topic of general interest is whether important life changes may play a role in the onset of cancer. The hypothesis of this study was that death of a husband or marital divorce, is associated with an increased risk of breast cancer. The study included 4491 incident breast cancer cases and 44,910 controls, matched on age, in a population-based nested case-control study, among Norwegian women born between 1935 and 1954. The risk of breast cancer among widowed compared to married women showed an odds ratio (OR) of 1.13 [95% confidence interval (CI) 0.94-1.36], after adjusting for age at first birth and parity. For divorced women the analogous OR was 0.83 (95% CI 0.75-0.92), after adjusting for age at first birth, parity and place of residence. Thus, the results did not show any clear evidence that death of a husband or marital divorce was associated with an increased risk of breast cancer.

Adult↗

Catch-up growth in Malawian babies, a longitudinal study of normal and low birthweight babies born in a malarious endemic area.

INTRODUCTION: Infant growth has not been studied in developing countries in relation to maternal factors related to malaria in pregnancy and maternal illiteracy. OBJECTIVE: To describe growth patterns in infants with low and normal birthweight and determine maternal risk factors for infant undernutrition. METHODS: Babies born in a rural district of southern Malawi were recruited. An infant cohort was selected on the basis of low or normal birthweight. Weight and length were recorded at birth and at 4-weekly intervals until at 52 weeks after birth. Maternal characteristics at first antenatal attendance and delivery were obtained. Odds ratios in univariate analysis were adjusted for birthweight. Factors included in the multivariate regression included maternal illiteracy, season of birth, maternal iron deficiency and number of infant illness episodes. RESULTS: Low birthweight infants were shorter and lighter throughout infancy than either normal birthweight or international reference values. At 12 months, placental or peripheral malaria at delivery (adjusted odds 1.8; 1.0, 3.1), number of infant illness episodes (AOR = 2.1; 1.2, 3.6) and maternal illiteracy (AOR = 2.7; 1.5, 4.9) were independently associated with low weight for age. Maternal short stature (AOR = 1.8; 1.1. 3.2), male sex (AOR = 2.4; 1.4, 4.1), number of infant illness episodes (AOR = 2.6; 1.5, 4.4), and birth in the rainy season (2.1; 1.2, 3.7) were independently associated with stunting. Placental or peripheral malaria at delivery (AOR = 2.2; 1.1, 4.4) and number of illness episodes (AOR = 2.2; 1.1, 4.5) were independently associated with thinness. CONCLUSION: Malaria during pregnancy and maternal illiteracy are important maternal characteristics associated with infant undernutrition. Innovative health/literacy strategies are required to address malaria control in pregnancy in order to reduce the magnitude of its effects on infant undernutrition.

Body Height↗

Effect of immediate neonatal zidovudine on prevention of vertical transmission of human immunodeficiency virus type 1.

OBJECTIVE: To describe the effects of various short zidovudine (ZDV) prophylactic regimens on vertical transmission of human immunodeficiency virus type 1 (HIV-I) infection, especially the effect of immediate neonatal ZDV prophylaxis. MATERIALS AND METHODS: The study included children of HIV-1-infected mothers who were born at a teaching hospital in Bangkok. The ZDV prophylaxis regimens varied by time periods that included: (1) no ZDV (1991-1996); (2) antenatal oral ZDV, 250 mg given twice a day starting at 34 to 36 weeks gestation and continued until labor (1995-1998); (3) antenatal oral ZDV plus immediate neonatal oral ZDV, 6 mg/0.6 mL/dose started within the first 2 hours after birth and continued at 6-hour intervals for 4 to 6 weeks (1997-1998); and (4) intrapartum intravenous ZDV given in addition to regimen 3 (1998-1999). Neonatal ZDV was administered within 2 hours after birth in 95% of the neonates. RESULTS: In a cohort of 136 children born at least 9 months before the analysis date, the HIV-1 vertical infection rates were: (1) no ZDV, 11 of 48 (22.9%, 95% confidence interval [CI] = 12.0-37.3); (2) late antenatal ZDV, 10 of 47 (21.3%, 95% CI = 10.7-35.7); (3) late antenatal ZDV plus immediate neonatal ZDV, 0 of 28 (0%, 95% CI = 0-12.3); (4) late antenatal, intrapartum intravenous ZDV, plus immediate neonatal ZDV, 0 of 13 (0%, 95% CI = 0-24.7). An estimated 0% (95% CI = 0-8.6) of the infants who received immediate neonatal ZDV with or without intrapartum ZDV were infected, as compared with 22.1% (95% CI = 14.2-31.8 ) of those who received no ZDV or only late antenatal ZDV (P < 0.001). CONCLUSIONS: The results of this study suggests high protective effect of immediate administration of neonatal ZDV. Perinatal components of antiretroviral prophylaxis provided the best results for protecting against vertical HIV-1 transmission.

Adolescent↗

[Social inequalities and other determinants of height in children: a multi-level analysis].

A cross-sectional household survey of height among children under five years of age (n = 2,632) was conducted in the city of Porto Alegre, Rio Grande do Sul State, Brazil. Multi-level linear regression was applied to investigate the effect of socioeconomic and demographic factors, physical and social environment, and health conditions on children s height, measured by the height-for-age z-scores of the National Center for Health Statistics standards. Area of residence (census tract) was classified as good versus poor in terms of housing and sanitation standards. On average, children s height was -0.18 z-score. Average height increased with maternal and paternal schooling, parents work skills, per capita family income, improved housing, maternal age, birth intervals, and birth weight. Height decreased with hospitalization in the first two years of life, number of under-five children in the household, and preterm birth. In the poor residential areas, the effect of maternal schooling was twice as great as in the better-off areas. The effect of parental work skills was only evident in the more deprived areas. Area of residence modified the effects of socioeconomic conditions on children s growth. Housing and sanitation programs are potentially beneficial to offset the negative effect of social disadvantage on children's growth.

Body Height↗

Age-dependent changes in the size of the upper lip in Bulgarians.

Age-dependent changes in the width and height of the upper lip were studied in 2,300 healthy Bulgarians aged from 3 days to 102 years, for the purposes of cheiloplasty in surgery and of visual art. It has been established that at the moment of birth, the upper lip is one of the most developed organs of the human body in both sexes and that it grows in size up to the age of 80 years, completing its intensive growth during the pre-school age while in the years of puberty it does not show the growth jump characteristic of the organism as a whole. In the males, the lip remains larger during the whole period of postnatal ontogenesis except for the early childhood; the difference in the height is most expressed (3.08 mm) in the 9th decade, and in the width (5.24 mm) even later. The conclusion has been drawn that cheiloplasty can be performed at any age including the first days after birth, the dimensions obtained at the age intervals under study serving as standards.

Adolescent↗

First-trimester growth and the risk of low birth weight.

BACKGROUND: Previous studies have demonstrated a correlation between first-trimester size and birth weight. It is not known, however, whether low birth weight is related to first-trimester growth. We sought to determine whether the risk of low birth weight and birth weight that was low for gestational age is related to the size of the embryo or the fetus in the first trimester. METHODS: From a data base of ultrasound records of more than 30,000 pregnancies, we identified women who had no important medical problems, a normal menstrual history, and a first-trimester ultrasound scan in which the crown-rump length of the embryo or fetus had been measured. We examined the relation between the outcome of 4229 pregnancies and the difference between the measured and the expected crown-rump length in the first trimester, expressed as equivalent days of growth. RESULTS: A first-trimester crown-rump length that was two to six days smaller than expected was associated with an increased risk (as compared with a normal or slightly larger than expected crown-rump length) of a birth weight below 2500 g (relative risk, 1.8; 95 percent confidence interval, 1.3 to 2.4), a birth weight below 2500 g at term (relative risk, 2.3; 95 percent confidence interval, 1.4 to 3.8), a birth weight below the fifth percentile for gestational age (relative risk, 3.0; 95 percent confidence interval, 2.0 to 4.4), and delivery between 24 and 32 weeks of gestation (relative risk, 2.1; 95 percent confidence interval, 1.1 to 4.0), but not with delivery between 33 and 36 weeks (relative risk, 1.0; 95 percent confidence interval, 0.7 to 1.5). CONCLUSIONS: Suboptimal first-trimester growth may be associated with low birth weight, low birth-weight percentile, and premature delivery.

Birth Weight↗