"Producto" comes from "product of pregnancy."

You can also say "singleton birth," but this is about the delivery process so it would be more appropriate to use "delivery." The translation would be:

"its use is limited to cephalic-presentation, (full-)term singleton deliveries"

OR:

"its use is limited to (full-)term singleton deliveries with cephalic-presentation" Example:

Blackwell Synergy - Birth, Volume 33 Issue 3 Page 203-209 ...
Three categories represent primary cesareans for **full-term singleton deliveries with cephalic presentation (referred to as "standard" deliveries)**, ...
www.blackwell-synergy.com/doi/abs/10.1111/j.1523-536X.2006....


4,680 references for "singleton deliveries". and 207 refs for "term singleton deliveries":

The incidence of small-for-gestational-age infants was 3% for neonates **in the 60 term singleton deliveries** and 7% in the entire cohort of 80 singleton ...
pt.wkhealth.com/pt/re/ajog/fulltext.00000447-200006000-00052.htm

This survey covered **19288 term singleton deliveries**, which according to the MBRN database represented 70.7% of all term singleton deliveries in Norway ...
linkinghub.elsevier.com/retrieve/pii/S0002937806006077

Serum C-reactive Protein and Chlamydia trachomatis Antibodies in ...
Methods: This was a nested case–control study of **104 spontaneous preterm singleton deliveries (cases) and 402 term singleton deliveries**, as controls, ...
www.greenjournal.org/cgi/content/full/106/1/73

Is a paediatrician needed at all Caesarean sections?
at 1 min of term singleton deliveries by the mode of delivery. Results: **The number of singleton term deliveries was 64 739**. When the data were analysed ...
www.blackwell-synergy.com/doi/abs/10.1046/j.1440-1754.1998....

Also, 45 refs for "full-term singleton deliveries":

The mean midluteal progesterone level for pregnancy cycles resulting in** full term singleton deliveries** was 25.85 ng/mL. The lowest level in this group was ...
staging.inciid.org/fertinews/progthresh.htm

Obstetrical & Gynecological Survey - Fulltext: Volume 62(3) March ...
They risk-adjusted cesarean rates by looking only at **full term, singleton deliveries**. They risk-adjusted neonatal outcomes for race/ethnicity, maternal age, ...
www.obgynsurvey.com/pt/re/obgynsurv/fulltext.00006254-20070...


Also, 20,200 references for "singleton births":

Data were derived from linked US birth/infant death files for 1995 and 1996, comprising **7465858 singleton births and 193266 twin births**. ...
aje.oxfordjournals.org/cgi/content/abstract/153/8/771)

Out of a total of 4731 singleton births 440 were preterm, .... The total number of singleton births was 4731, thus giving a singleton preterm birth rate of ...
www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1790851