This document summarizes a presentation on searching for semen phenotypes that are predictive of impaired male fecundity. The study analyzed data from 501 couples in the Longitudinal Investigation of Fertility and the Environment study. It found that several semen morphology measures, including abnormal tail shape and head shape, were weakly associated with longer time to pregnancy of over 6 months after adjusting for factors like age, smoking, and previous pregnancies. However, semen phenotypes provided only modest predictive value beyond traditional risk factors. Larger studies are needed to better understand variations in male fecundity.

1. Searching for semen phenotypes in
impaired male fecundity
Chirag J Patel
Raji Sundaram, Germaine Buck Louis
Epi Congress, Miami
06/22/16
chirag@hms.harvard.edu
@chiragjp
www.chiragjpgroup.org

2. Sperm count, morphology, and motility have been
hypothesized to be predictive of fecundity…
However, prognostic utility of semen phenotypes under
debate and elusive.
Lack prospective cohorts to examine association
between sperm phenotype and male fecundity.

3. Semen phenotypes are important for fertility…
but clinical use have been debated.
NEJM, 2001
Semen and the curse of cutoffs.
Niederberger, J Urol 2011
Fertil Steril, 2013

4. What sperm phenotypes have utility of prediction of
impaired couple fecundity (> 6 cycles to pregnancy)?

5. Longitudinal Investigation of Fertility and the
Environment (LIFE): a prospective study of couples
desiring to become pregnant
• Reproductive age (18-40 for females; >18 for males)
• N=501 couples (Michigan and Texas) in 2005-2007
• Data collected in couples’ home
• urine, blood, semen (at baseline and at month 1)
• pregnancy and fertility monitors (ClearBlue)
• monitors and journals used to define menstrual cycle
Buck Louis et al, 2013
Buck Louis et al, 2014

6. EHP, 2012
Fertility and Sterility, 2014
“male and female persistent pollutants and reduced fecundibility…”
“male phthalates and 20% reduction in fecundity…”

7. Fertility and Sterility, 2014

8. 35 semen phenotypes:
5 general, 8 motility, 6 head measures, 12
morphology, 2 chromatin stability
Buck Louis, 2014
general
count
volume
concentration
straw distance
hypo-osmotic swollen
motility
average path
straight & curvilinear velocity
amplitude head displacement
beat cross frequency
% motility
% straight
% linear movement
% normal (2 criteria)
% amorphous
round
pyriform
bichephalic
tapered
megalo/micro head
neck/midpiece abnorm.
coiled/other tail abnorm.
immature sperm
cytoplasmic droplet
morphology head
length
width
perimeter
% elongation factor
area
% acrosome
chromatin
% fragmentation
high fragmentation sustain.

9. 35 semen + 5 risk factors have modest ρ
motility/morphology
head/morphology
chromatin/morphology
head
34 PCs (out of 40)~ 99% of variation
Effective number of variables: 38 (vs. 40)
WHO normal and strict criteria

10. Impaired fecundity and “traditional” risk factors
Time-to-pregnancy (TTP) > 6 cycles (N=402)
TTP ≤ 6
mean (SE)
TTP > 6
mean (SE)
p-value
Age (year) 31.2 (0.3) 33.3 (0.5) 0.0005
BMI (kg/m2) 29.8 (0.3) 29.2 (0.6) 0.6
Lipids (ng/g) 726.8 (12) 713.5 (22) 0.6
Cotinine (mg/dL) 40.9 (6.7) 79.9 (17.3) 0.04
Previous
pregnancies (#)
1.3 (0.04) 1.6 (0.13) 0.07
N=302 N=100

11. LIFE Study
35 semen and 5 non-semen
Prospective TTP
Time-to-pregnancy IQR: 1-6
N=302 and 100
TTP > 6? = Pi + age
Pi
n=40
age-adjusted
logistic regression
False discovery rate < 10%:
Px … Pz
TTP > 6? = age + father + BMI +
cotinine + Px + … + Pz
TTP > 6? = age + father + BMI +
cotinine
versus

12. OR in time-to-pregnancy > 6 cycles:
5 morphological phenotypes
Age-adjusted
FDR < 10%
head
f(volume, count, concentration, motility)
f(head, neck, tail)

13. ROC Curve for TTP > 6, AUC=0.730 [green]/0.673 [red]
False positive rate
Truepositiverate
0.0 0.2 0.4 0.6 0.8 1.0
0.00.20.40.60.81.0 Sperm phenotypes offer modest predictive boost
over “traditional” factors (age, smoking, fathered)
p < 0.05
Nagelkerke R2:
0.2 vs 0.1
OR P
Age* 1.66 (1.29, 2.15) 0.0001
Fathered? 0.45 (0.26, 0.75) 0.002
BMI* 0.87 (0.67, 1.11) 0.25
Cotinine* 1.27 (1.01, 1.60) 0.04
% Normal* 1.23 (0.73, 2.12) 0.44
% Coiled Tail* 1.52 (1.09, 2.14) 0.02
% Pyriform* 1.46 (1.08, 2.01) 0.01
% Amorphous* 1.57 (1.07, 2.35) 0.03
* per 1 SD

14. Conclusions:
Semen phenotypes modest prognostics for TTP > 6
cycles
Weak to moderate associations between sperm phenotypes
and time to pregnancy greater than 6 cycles.
Little predictive value beyond common risk factors of age,
smoking, and history.
Cannot rule out measurement errors and residual confounding.
Larger sample sizes and more measures to describe variance in fecundity.

15. Chirag J Patel
chirag@hms.harvard.edu
@chiragjp
www.chiragjpgroup.org
NIH Common Fund
Big Data to Knowledge
Acknowledgements
RagGroup
Chirag Lakhani
Adam Brown
Danielle Rasooly
Arjun Manrai
Erik Corona
Nam Pho
Germaine Buck Louis
Rajeshwari Sundaram