Complexity-simplicity, creativity, intelligence, and other correlates.

To evaluate the intrauterine growth potential of infants that die from sudden infant death syndrome (SIDS), the authors compared SIDS infants with their surviving siblings. The SIDS sibships themselves were also compared with sibships where all infants survived. Data from the population-based Medical Birth Registry of Norway, with 1.3 million births during 1967-1988, were used. From the birth cohorts, 1,984 SIDS cases were identified. All births were linked into sibships. The mean birth weight and gestational age were calculated across sibships of different sizes for first to fourth birth order. In a further analysis, birth weights were standardized to adjust for gestational age. Mothers of SIDS infants give birth to smaller babies in general. SIDS infants weighed, on average, 85 g less at birth than their siblings and 164 g less compared with babies in nonaffected sibships. When birth weights were standardized for gestational age, most of the weight difference between SIDS infants and siblings was due to a shorter gestational age of SIDS infants, while the difference between surviving siblings of SIDS infants and births from nonaffected sibships remained. All births in sibships with a SIDS infant were intrauterine growth retarded. This may reflect factors that contribute to SIDS risk (such as maternal smoking). The factors that contribute to shorter gestational age and further slowing of growth in the SIDS infants may specifically influence the SIDS infant and not its siblings.

Birth Order↗

PubMed1995

First trimester feeding in a rural Sri Lankan population.

One hundred Sinhalese mothers with infants at three months age in a rural population in Central Sri Lanka were interviewed by questionnaire on the feeding of their infants from birth to 3 months of life. 96% of babies were being breast fed at 3 months age. However, 32% have already been started on formula. Of this 32, eight mothers were from poor families receiving state subsidies. 20 of the 32 were giving expensive formulas made by multinational companies, (including four of the eight mothers receiving state subsidies and feeding formula) in spite of the availability of cheap comparable state subsidized formulas. In rural Sri Lanka only about a quarter have access to drinking water but 96% were giving water or other weak nutritional solutions at 3 months of age. 72% were using bottles for feeding. 77% were being given sugar and, 13% salt through non-milk solutions while 11% were getting sugar through their formula. Maternal employment, increasing maternal age, less than sixteen hours of maternal contact time per day with child, delay in initiation of breast feeding after birth were all significantly associated with a higher risk of formula feeding. A lower birth order and early initiation of breast feeding after birth were associated with a higher risk of babies being fed on non-milk solutions. In the light of these findings it is suggested that the time is now opportune for the National Nutritional Programme to shift its present emphasis from the promotion of breast feeding in these (and similar) areas to the promotion of exclusive breast feeding in the early infant's diet, while discouraging formulas, non-milk solutions, weaning foods, salt, sugar and the use of the bottle as a feeding utensil.

Birth Order↗

PubMed1995

Birth order, delivery route, and concordance in the transmission of human immunodeficiency virus type 1 from mothers to twins. International Registry of HIV-Exposed Twins.

BACKGROUND: We evaluated data from prospectively identified twins to understand better the mechanisms and covariates of mother-to-infant transmission of human immunodeficiency virus (HIV). METHODS: Using data obtained from an international collaboration and multivariate quasilikelihood modeling, we assessed concordance, birth order, route of delivery, and other factors for HIV infection in 115 prospectively studied twin pairs born to HIV-infected women. Actuarial methods were used to evaluate overall survival and survival free of acquired immunodeficiency syndrome for HIV-infected twins. RESULTS: Infection with HIV occurred in 35% of vaginally delivered firstborn (A) twins, 16% of cesarean-delivered A twins, 15% of vaginally delivered second-born (B) twins, and 8% of cesarean-delivered B twins. In a multivariate model, the adjusted odds ratios for HIV infection were 11.8 (confidence interval: 3.1 to 45.3) for concordance of infection with the co-twin, 2.8 (confidence interval: 1.6 to 5.0) for A versus B twins, and 2.7 (confidence interval: 1.1 to 6.6) for vaginally delivered versus cesarean-delivered twins. Among A twins, 52% (lower confidence limit: 6%) of the transmission risk was related to vaginal delivery. Comparing vaginally delivered A twins (infants most exposed to vaginal mucus and blood) to cesarean-delivered B twins (infants least exposed), 76% (lower confidence limit: 48%) of the transmission risk was related to vaginal exposure. Infected B twins had slightly reduced Quetelet indexes and more rapid development of illnesses related to acquired immunodeficiency syndrome. CONCLUSIONS: These results indicate that HIV infection of B twins occurs predominantly in utero, whereas infection of A twins (and, by implication, singletons) occurs predominantly intrapartum. We propose that intrapartum transmission is responsible for the majority of pediatric HIV infections and that reducing exposure to HIV in the birth canal may reduce transmission of the virus from mother to infant.

Birth Order↗