The HIV prevalence among pregnant women in the Amsterdam region (1988-1991).

The objective of the study was to monitor the HIV prevalence in the years 1988-1991 among pregnant women in the Amsterdam region, visitors to an abortion clinic and 3 outpatient infertility clinics. All women attending these clinics were asked to participate in the study on a voluntary basis and were tested with informed consent. The women were questioned about risk-bearing behaviour of themselves and their sexual partner(s). In the period 1988-1991, of the 23,827 eligible pregnant women, 22,165 women participated (93.0%). Twenty-seven women were found to be positive for HIV antibodies (0.12%, 95% CI: 0.08%-0.17%), of whom twenty belonged to a known HIV risk group or had a partner who belonged to one of these groups and 7 women had no known HIV risk. Seventeen of the 27 women had a foreign nationality. The annual HIV prevalence among pregnant women was: 1988: 0.28%; 1989: 0.10%; 1990: 0.10%; 1991: 0.11%. In the years 1990 and 1991, of the 1,128 eligible women visiting the abortion clinic 953 (84.5%) were tested. Eleven women were HIV-seropositive (1.15%, 95% CI: 0.6%-2.0%), of whom 9 were from an AIDS endemic region, 1 woman had a partner from this region and 1 woman had no known HIV risk. Four African women had HIV-2 antibodies. At the 3 outpatient infertility clinics 1 woman was found to be HIV-positive (0.13%; 95% CI: 0.02-0.9). She had no other risk than a partner from an AIDS endemic area. In the Amsterdam region there was a steady and low HIV prevalence (0.1%) among pregnant women through the years 1988-1991. The prevalence in the abortion clinic was ten times higher. The program was able to detect possible high risk groups within the population. Migration and travelling can play an important role in the spread of HIV in the general heterosexual population.

[HIV prevalence in pregnant women in and around Amsterdam in 1989]. / HIV-prevalentie bij zwangeren in en rond Amsterdam in 1989.

The HIV prevalence among pregnant women in 3 hospitals in Amsterdam was found to be 0.28% in 1988. As the population of these 3 hospitals is not representative of all pregnant women in Amsterdam, this study--which is done on a voluntary basis--in 1989 was slowly extended to all hospitals, clinics and practices of midwives. Of 5,176 pregnant women who were eligible in 1989, 4,812 (93.0%) participated in the study. Non-Dutch women were overrepresented among the refusers. Antibodies to HIV were found in 5/4, 812 women (0.10%, 95% confidence interval 0.01-0.19) and all 5 infected women reported an AIDS risk factor either for themselves or for their present or previous partner(s). Three of the infected women were only tested during the third trimester; the 2 others were tested in the first trimester of their pregnancy and underwent an abortion. The prevalence in 1989 was lower than that found in 1988 and this may have been influenced by an increased effort to counsel seropositive women--and especially intravenous drug users--on the risk of pregnancy.

[The prevalence of HIV in pregnant women at 3 outpatient clinics in Amsterdam]. / HIV-prevalentie bij zwangeren in drie poliklinieken in Amsterdam.

Pregnant women who were seen in 3 hospitals in Amsterdam were tested for antibodies to HIV, after informed consent. Out of 2,308 eligible pregnant women, 2,094 (90.7%) participated by name and 21 (0.9%) anonymously; 193 (8.4%) refused to participate. Among refusers there were significantly more women with a non-Dutch nationality or born in other countries. Of 2,115 pregnant women, 6 were found to be HIV-infected (0.28%, 95% confidence interval (0.05-0.51). Among women who at their first prenatal visit reported no AIDS-risk factor either for themselves or their partner(s), the HIV prevalence was 1/1,893 (0.05%) and among women with such risk factor the prevalence was 5/180 (2.78%). Three of the seropositive pregnant women knew before they were tested that they were HIV-infected. Of the 6 HIV-infected women one had a spontaneous abortion and the 4 women who were tested within the period when therapeutic abortion was still possible, decided to continue their pregnancy.

Basal lamina thickening in the placentae of smoking mothers.

The thickness of the basal lamina in the placentae of 20 matched pairs of smoking and non-smoking mothers was measured using an electron microscopic method of quantification. A significant increase of the thickness of the trophoblastic basal lamina was found in the smokers' placentae: 181 nm (s.d. +/- 38.2 nm) in non-smokers versus 286 nm (s.d. +/- 69.9 nm) in smokers (P less than 0.005). A significant increase of the thickness of the capillary basal lamina was also found: 75 nm (s.d. +/- 12.1 nm) in non-smokers versus 111 nm (s.d. +/- 16.0 nm) in smokers (P less than 0.005). The number of duplications around the capillary basal lamina was found to be increased in the placentae of smoking women.

Smoking in pregnancy: the influence on percentile birth weight, mean birth weight, placental weight, menstrual age, perinatal mortality and maternal diastolic blood pressure.

Smoking habits of 597 pregnant women were investigated; 48.6% of the women smoked during pregnancy. Percentile birth weight proved to be decreased compared with the Amsterdam birth weight charts. This decrease could be attributed largely to smoking in pregnancy. Mean birth weight was significantly lower in smokers than in nonsmokers (230 g; p less than 0.01). Placental weight and menstrual age were not affected by smoking during pregnancy. A statistically significant higher incidence of hypertension in pregnancy in the nonsmokers group compared with the smokers group (p less than 0.05) was established.

Structural changes in the placenta of smoking mothers: a quantitative study.

Placentae of matched pairs of smoking and non-smoking mothers have been investigated by quantitative light microscopic techniques. A smaller diameter of the villous capillaries, a decrease in vasculosyncytial membranes and basement membrane thickening were observed in the placenta of smoking mothers. Quantitative morphometric methods showed a significant decrease in volume density of the fetal vessels in the terminal villi of the smoker's placenta. The exchange area of the smoker's placenta was shown to be decreased. The pathophysiological mechanisms leading to these changes and the possible role of toxic agents (i.e., cadmium) are discussed.

Influence of cadmium on placental structure.

Placentas of smoking and nonsmoking mothers have been investigated with light microscopical techniques. The cadmium content of the same placentas had been determined in a previous study by means of atomic absorption spectrophotometry (AAS). The cadmium content of the placentas from smokers was found to be elevated, compared to that of nonsmokers. The volume density of the vascular bed in the terminal villi of the placentas of smokers was found to be decreased. Preliminary results of experiments in course with rats exposed to 0.2 mg CdCl2/kg body wt/day (by subcutaneous injection) seem to indicate that in the placenta of rats, the volume density of the blood vessels in the placental stroma is likewise reduced in the exposed animals.