Fertility and female dietary exposure to persistent organochlorine compounds - The fishermen’s wives

Animal studies have shown that exposure for PCBs, can effects the menstrual cycle and cause reduced fertility in females. In humans, fertility can be measured by examining the waiting time to pregnancy, ie the time between the time when a couple stop using contraception and the time when the woman becomes pregnant. This can be measured only if the pregnancy was planned. Once pregnancy has been established, it is possible to examine fetal survival by looking at miscarriage risk. In Sweden consumption of fatty fish (such as salmon and herring) from the Baltic Sea is one of the major sources of exposure to PCB. It has previously been shown that Swedish fishermen and their families eats more fish than the general population. In order to study the possible health effects of exposure to PCBs through consumption of fatty fish from the Baltic Sea, groups of fishermen from the Swedish east coast have been identified. By matching with different registers groups of wives and ex- wives of the fishermen (fishermen's wives), and groups of sisters and half-sisters (fish sisters) have been identified. As a reference population (non-exposed), corresponding groups have been identified among fishermen on the Swedish west coast. Questionnaires were sent to the wives of fishermen and fish sisters to gather information about their first planned pregnancy. Besides waiting time to pregnancy questions were also asked about pregnancy outcomes in order to calculate the risk of miscarriage. The response rate in both groups was just under 60% (1090 West and 505 East Coast fishermen's wives, and 1103 West and 709 East Coast fish sisters). In 121 East Coast fisher wives and 165 East Coast fisher sisters blood samples were analyzed to determine the concentration of the CB 153. This concentration was then used as a measure of exposure to PCBs. Purpose: To investigate whether exposure to persistent organochlorine compounds through the consumption of fatty fish from the Baltic Sea leads to a decreased fertility, measured as time to pregnancy, to investigate whether the same exposure implies an increased miscarriage risk, and to assess the relation between blood levels of PCB and the reproductive outcomes time to pregnancy and miscarriages. For each woman’s five first pregnancies, information was collected on the use of contraceptives prior the pregnancy, time to pregnancy for those pregnancies that where planned, pregnancy outcome, and whether the pregnancy was a result of any medical treatment or a birth control failure. Working situation (working/not working, full/part time, shift work and night work) and heavy lifting was asked about for the woman, whereas smoking habits and coffee consumption was assessed for both the woman and her partner. The women were asked if they at any point in their life unsuccessfully had tried to conceive for a consecutive period of at least 12 months, and how many children they had. Furthermore, they were asked if they had grown up in either a fisherman’s family or in a fishing village. Their current fish consumption was assessed as “never”, “1-4 meals/month”, “5-14 meals/month” and “at least 15 meals/month” for lunch and dinner separately