McGregor I A, Wilson M E, Billewicz W Z
Trans R Soc Trop Med Hyg. 1983;77(2):232-44. doi: 10.1016/0035-9203(83)90081-0.
The incidence of placental malaria at parturition and its effects on the conceptus have been investigated in The Gambia, West Africa. Malarious placentae occurred in 1300 (20.2%) of 6427 singleton births, in 32 (18.6%) of 172 sets of twins and in none of six sets of triplets. Plasmodium falciparum infections predominated; P. malariae or P. ovale infections were found in only nine instances. In the large group of single births placental malaria occurred less frequently (12.0%) in residents of urban than of other, more rural, communities (27.1%). In the former group incidence showed no clear change with season; in the latter group it was highest in the trimester following the end of the rains and lowest in the second half of the dry season. In both residential groups it was more frequent in primiparae (urban 16.1%; other 46.9%) than in multiparae (urban 8.9%; other 20.3%). The sex of the child did not influence malaria incidence. Dense placental infections were more frequent in primiparae. Stillbirth rates of singleton infants were significantly higher for males than for females, but no clear and consistent relationship between stillbirth and placental malaria was detected. Mean singleton birthweights were depressed by about 170 g in the presence of malaria; the deficits were statistically significant only among first born infants and tended to diminish progressively with increasing maternal parity. No distinct gradient linking birthweight with ascending density of placental parasitaemia was observed. Singleton birthweights of 2.5 kg or less occurred more frequently in association with malarious than non-malarious placentae and the association was more marked among first born than later birth rank infants. Differences between the weights of malarious and non-malarious placentae were small and not significant. The findings of the study are discussed in relation to the widely prevalent view that pregnancy exacerbates maternal malaria by attenuating acquired immunity.
在西非的冈比亚，对分娩时胎盘疟疾的发病率及其对胎儿的影响进行了调查。在6427例单胎分娩中，有1300例（20.2%）出现患疟疾胎盘；在172例双胞胎中有32例（18.6%）出现；而在6例三胞胎中未出现。恶性疟原虫感染占主导；仅在9例中发现间日疟原虫或卵形疟原虫感染。在大量单胎分娩组中，城市居民的胎盘疟疾发生率（12.0%）低于其他更乡村社区的居民（27.1%）。在前一组中，发病率随季节无明显变化；在后一组中，在雨季结束后的三个月中最高，在旱季后半段最低。在两个居住组中，初产妇的发病率（城市16.1%；其他46.9%）均高于经产妇（城市8.9%；其他20.3%）。孩子的性别不影响疟疾发病率。初产妇中密集的胎盘感染更为常见。单胎男婴的死产率显著高于女婴，但未发现死产与胎盘疟疾之间存在明确且一致的关系。出现疟疾时，单胎平均出生体重降低约170克；仅在头胎婴儿中，这种差异具有统计学意义，且随着产妇胎次增加有逐渐减小的趋势。未观察到出生体重与胎盘寄生虫血症密度升高之间有明显梯度关系。出生体重在2.5千克及以下的单胎，与患疟疾胎盘相关的情况比与未患疟疾胎盘相关的情况更频繁，且这种关联在头胎婴儿中比在晚产婴儿中更明显。患疟疾胎盘与未患疟疾胎盘的重量差异很小且无统计学意义。结合普遍认为妊娠会通过削弱获得性免疫而加重母体疟疾这一观点，对该研究结果进行了讨论。
