Fertility in four regions spanning large contrasts in serum levels of widespread persistent organochlorines: a cross-sectional study

Table 1 Target populations and data collection in an international study of fertility.

	Warsaw^a	Kharkiv^a	Greenland^a	Sweden^b	Total
Eligible female target population, n	690	2478	665	1439	5272
Interviewed, n	472	640	598	559	2269
Participation rate, %	68	26	90	39	43
Contraceptive failures, %	19	48	6	21	26
Provided valid TTP^c, n	376	307	520	519	1722
Stated TTP, n	369	301	455	513	1638
Calculated TTP, n	7	4	57	0	68
TTP in cycles ^d , n	0	2	8	6	16
Questionnaire, men^e, n	472	576	637	195	1880
Eligible men addressed for the semen study	690	640	256	2783	4369
Collected semen samples^f	198	208	201	191	798
Participation rate, %	29	33	79	7	18
Sperm motility, manual counting	190	208	200	188	786
Sperm motility, computer assisted	165	0	198	179	542
Sperm morphology	197	206	200	184	787

a) Consecutive pregnant woman and their spouses.
b) Retrospective studies of past pregnancies.
c) TTP were considered not valid if the woman was using birth control when becoming pregnant (47 Inuits, 47 Warsaw women, and 297 Kharkiv women), did not provide information on whether she was using birth control (n = 26), was multipara and had not menstruated since her previous pregnancy (n = 16), or had not provided information on whether she had menstruated since her previous pregnancy (n = 5).
d) Possibly censored measure.
e) The total number of individuals with questionnaire information on males. Data were obtained by interviewing the spouse if no male interview was performed.
f) All collected semen samples were analysed for sperm concentration and volume.

ISSN: 1476-069X