Wednesday, 8 September 2010
Home Pregnancy Tests during the Two Week Wait
I know that many people warn against home pregnancy tests (HPTs) during the two week wait, but as my stash above indicates, I am not one of them. The last peer-reviewed head-to-head comparison of HPTs was by Cole and colleagues in 2005, so I picked the top brands from that study and then used the the manufacturers' own data on early sensitivity. I don't know the extent to which these results are directly comparable, as they were tested in different laboratories on different women. From these data, the First Response Early Result test came out looking the best, although all are equal by Day 0.
What about false positives? Cole and colleagues (2005) found no false positives in their lab test tests. Clearblue Digital reports a 0.49% rate of false positives on Day 0. First Response state that women over 41 years old could expect a 4% false positive rate on Day 0 due to high levels of pituitary hCG.
So here is my plan:
Thursday (3dp3dt): Daily tests until I get a negative result to ensure that the trigger is out of my system, then:
Sunday (6dp3dt): Daily tests until Friday 17th (11dp3dt).
Monday 20th (14dp3dt): Blood test.
First Response Early Result true positives
First Response Early Result false positives
Clearblue analogue colour change tip
Cole, LA et al., 2005. Sensitivity of Over-the-Counter Pregnancy Tests: Comparison of Utility and Marketing Messages. Journal of the American Pharmacists Association.
Echner, SF and Timpe, EM. 2003. Urinary-Based Ovulation and Pregnancy: Point-of-Care Testing. The Annals of Pharmacotherapy.
Cole, LA. 2004. Accuracy of home pregnancy tests at the time of missed menses. American Journal of Obstetrics and Gynecology.
Butler, SA. 2001. Detection of Early Pregnancy Forms of Human Chorionic Gonadotropin by Home Pregnancy Test Devices. Clinical Chemistry.