Environmental pollutants: Reduced chance of pregnancy?
Perfluorinated compounds do not affect the chances of becoming pregnant, according to a sub-study from the Norwegian Mother and Child Cohort Study (MoBa). Previous research had indicated a correlation between PFC levels in the blood and the time taken for women to conceive.
A group of 910 women from MoBa who were pregnant in 2003 and 2004 were included in the sub-study. Of these, 416 were selected because it had taken more than 12 months to become pregnant, despite not using birth control and actively trying to conceive. The researchers studied both first-time mothers and women who had given birth more than once.
- Among those with the highest PFC levels, there was a doubled risk of having trouble conceiving
- Among first-time mothers there was no correlation between PFC levels and a reduced chance of getting pregnant
- Among mothers who had had more than one child, PFC levels were somewhat higher among those who took a long time to conceive.
PFC levels normally decrease during pregnancy and breastfeeding because the compounds are excreted in breast milk. As PFC levels can increase over time between the pregnancies, increased levels could be a consequence of the long interval between pregnancies, and not necessarily be a cause.
A Danish study from the period 1996-2002 concluded with a link between high PFC levels and reduced chances of conception. One important difference is that the levels measured were significantly higher in this period; the level has generally declined in recent years. The Danish study did not differentiate between first-time pregnancies and subsequent pregnancies. The study from MoBa therefore appears to provide a clearer picture and suggests that PFCs do not reduce the chances of becoming pregnant.
The study was a collaboration between the Norwegian Institute of Public Health and the National Institutes of Environmental Health in the United States.
Facts about PFCs
- PFC compounds are found in a number of impregnated consumer products, textiles, carpets and food packaging.
- Fish and shellfish are the main food sources of these compounds.
- Breast milk is the main source for breast-feeding children.
- The interior environment can contribute to intake of PFC.
- Use has declined substantially over the past decade, but PFCs are detected in the blood from mothers and newborn children and in breast milk
- The compounds are broken down very slowly and can harm living organisms and are therefore seen as pollutants
Whitworth, Kristina W.; Haug, Line S.; Baird, Donna D.; Becher, Georg; Hoppin, Jane A.; Skjaerven, Rolv; Thomsen, Cathrine; Eggesbo, Merete; Travlos, Gregory; Wilson, Ralph; Longnecker, Matthew P. Epidemiology 2012; 23: 257–263. Perfluorinated Compounds and Subfecundity in Pregnant Women.