Malaria chemosuppression in pregnancy. V. Placenta malarial changes among three different prophylaxis groups

Trop Geogr Med. 1993;45(6):274-9.

Abstract

The effect of malaria chemoprophylaxis during pregnancy on placenta malarial changes (PMCs) was investigated in 170 tissue sections. Women of 63 sections received daily proguanil (PROG), 61 once weekly chloroquine (CQ) and 46 the two drug combination (CQ+PROG). All were residents of a malaria hyperendemic area in Muheza District, Tanzania. Supervised prophylaxis started early in pregnancy till delivery. Parasitaemias and clinical episodes were detected early and radically treated. Overall, PMCs were mostly infrequent and light viz: fibrinous deposits (98%), fibrinoid necrosis (60%), leucocytic infiltrations (59%), macrophage containing pigment (16%), and malaria parasites (8%). The type, prevalence, and severity of the PMCs in the three prophylaxis groups were comparable. This was despite the fact that PROG and CQ+PROG were prophylactically more efficacious than CQ and despite the expectation that the prevalence and severity of the PMCs would be high in the CQ group. Prompt diagnosis and effective treatment of parasitaemias in this group contributed to the low prevalence and less severity. It is concluded that effective malaria chemoprophylaxis or prompt diagnosis and effective treatment of malaria parasitaemias have significant impact on the prevalence of PMCs. Due to various operational constraints in most developing countries, chemoprophylaxis remains the only feasible broad option for malaria control in pregnancy.

PIP: The study area was Muheza District, north-eastern Tanzania, where some study participants delivering at Muheza District Hospital were matched with non-participants delivering at the same hospital (controls). Comparison of pathologies in the 3 prophylaxis groups was based on the results of 170 randomly selected placenta tissue sections (63 daily proguanil (PROG), 61 once weekly chloroquine (CQ), and 46 CQ+PROG) from women who received prophylaxis for more than 10 consecutive weeks before delivery. The histological features in decreasing order of frequency were: fibrinous deposits (98%), excessive fibrinoid with a possible damage to the villi (villus atrophy) (60%), leucocytic infiltrations (59%), macrophage containing pigment (16%), and lastly malaria-infected red blood cells (8%). Most placenta malarial changes (PCMs) were not associated with major destruction of placenta structures, and parasites did not adhere on the syncytiotrophoblast. Villi atrophy was found in only a few sections with fibrinous deposits. Overall, there were no significant differences in the frequencies of various components of placenta histology by parity and the maternal malaria prophylaxis regimen during pregnancy (p 0.05). In all groups, pathologies were mostly light. The frequency of classes in the 3 prophylaxis groups did not differ significantly (p 0.05). Overall, 133 (78%) of all placentae had no evidence of active or passed infection, while 24 (14%) had signs of past malaria infection and 13 (8%) had signs of active infection. The results of microscopic examination for malaria parasites in the placenta using the placental blood smear were compared with those obtained from the histological examination of the placenta tissue. Only 154 paired histology-blood smear examinations were possible. Examination of placental blood smears revealed twice as many placentae with malaria parasites as those detected by the histological examination of the placenta tissue (p 0.01). The 2 examinations gave the same results in 115 pairs (7 positive and 118 negatives) and differed in 29 pairs (23 smear positive but tissue negative, while 6 were tissue positive but smear negative).

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chloroquine / therapeutic use*
  • Drug Therapy, Combination
  • Female
  • Humans
  • Malaria / parasitology
  • Malaria / pathology
  • Malaria / prevention & control*
  • Placenta Diseases / epidemiology
  • Placenta Diseases / parasitology
  • Placenta Diseases / pathology*
  • Pregnancy
  • Pregnancy Complications, Parasitic / parasitology
  • Pregnancy Complications, Parasitic / pathology
  • Pregnancy Complications, Parasitic / prevention & control*
  • Proguanil / therapeutic use*
  • Tanzania / epidemiology

Substances

  • Chloroquine
  • Proguanil