Ethnic and environmental factors affecting fetal growth in Papua New Guinea

Abstract

We studied 738 live singleton births in Papua New Guinea to examine the contribution of ethnic origin and environmental factors to birth weight and gestation. Maternal history, examination and post-partum anthropometry, infant anthropometry and clinical gestational assessment were performed, and placental blood slides and histology were examined. Mothers from Highlands provinces who delivered on the coast had larger babies (mean birthweight 3.34 SD 0.48 kg) than either indigenous coastal mothers (mean 3.10 SD 0.51 kg) or those migrating to Port Moresby from other coastal regions (mean 3.14 SD 0.51 kg). This was due to a combination of longer gestation and better intrauterine growth (assessed by birthweight standard deviation scores). Gestation was slightly longer in Highlands mothers delivering on the coast compared with those delivering in the Highlands, but birthweight standard deviation scores were unchanged. Malarial infection of the placenta was almost never found. Stepwise regression analysis showed that parity, maternal height, Highlands origin and maternal body mass index (weight/height2) were all significant predictors of birthweight standard deviation score, while maternal body mass index and Highlands origin were predictors of gestational length. We conclude that Highland mothers have a tendency to deliver heavier babies, and do not demonstrate the fetal growth-retarding effects of altitude seen in other races. Although the incidence of low birthweight was only 7.1% in our study, we found that indices of maternal nutrition were predictors of birth weight.

Anaemia- and malaria-attributable low birthweight in two populations in Papua New Guinea

“…Pregnant women in Madang have high spleen rates (50%) at first antenatal visit (Brabin, Brabin, Sapau and Alpers 1988), and monthly malaria incidence during pregnancy averages 20% in primigravidae and 15% in multigravidae (Brabin et al 1990b). This contrasts sharply with Goroka, where malaria in pregnancy is exceptional and splenomegaly unusual (Primhak and MacGregor 1991). The high prevalence of splenomegaly during pregnancy in Madang is associated with an increased risk of malaria-related anaemia, as many women have spleens which are several centimetres Ann Hum Biol Downloaded from informahealthcare.com by Michigan University on 11/03/14…”

“…In the Highlands an earlier report for the previous decade showed a comparable birthweight distribution to this Goroka sample (Greenfield 1983). An earlier study suggested that migration was not thought to be an important factor influencing birthweight distribution in coastal and highland populations (Primhak and MacGregor 1991).…”

“…Surveys from rural coastal Madang have estimated that about 70% of women attend for antenatal care (Brabin et al 1990a), and in Goroka the figure is nearer 50% (Primhak and MacGregor 1991).…”

Longitudinal weight growth patterns in the highland fringes of West Sepik Province, Papua New Guinea: a comparison of three groups

“…Where sample size is very low (<5-10), even significant differences are likely to be vulnerable to uncontrolled variables such as parity and maternal factors (cf. Allen 1989, Primhak andMacGregor 1991), and should be viewed very cautiously. Elsewhere it may be helpful to keep in consideration the absolute values of the results and not to attend solely to statistical significance.…”

“…Haas, Moreno-Black, Frongillo, Pabon, Pareja, Ybarnegaray and Hurtado 1982). Highland/lowland differences within PNG's more modest altitude range have also been reported, but here it is lowlanders who generally have the lower birthweights: the complex of causes identified includes ethnic origin and maternal nutritional status (Aitken 1987, Primhak andMacGregor 1991). The East Mianmin birthweights are within the expected range for a highlands population, albeit the lower part of it (cf.…”