Table 5. Gestation period in relation to dose and the parental mouse treatment.

Drug	Dose (mg/kg)	Dam Sample size (n)	aGestation period afterFirst mating (Days ± SD)		bGestation period afterRepeat mating (Days ± SD)
			Father-only	Both-parents	Father-only	cBoth-parents
None	None	10	26.0±1.4	26.0±1.4	26.0±1.4	26.0±1.4
EMS	480	10	22.4±2.3	24.4±4.2	20.0†	24.0±4.4
ZDV	10	10	20.7±2.9	23.1±2.8	17.5±0.7	20.5±4.9
	100	10	22.0±4.2	17.0†	20.5±0.7	18.0†
	250	10	22.0†	25.0±3.6	20.0†	20.5±2.1
NVP	5	10	21.5±3.5	18.8±1.0	24.5±2.1	-
	50	10	22.0±0.0	19.8±4.4	21.4±4.5	20.5±3.0
	150	10	-	18.9±1.9	22.5±2.1	20.5±3.5

Four males per dose mated five females each to give a total of twenty dams per dose. Ten of these dams were untreated (“father-only” treated groups) while the other ten had received the same dose as the males (“both-parents” treated groups) for 56 days before mating. Harem mating was done by co-housing one male and five females for 10 days without checking for vaginal plugs. ZDV = Zidovudine; NVP = Nevirapine; EMS = Ethylmethylsulfonate (one-time dose); SD = Standard Deviation.

^aAverage gestation period obtained for dams mated to males on therapy at the time of mating.

^bAverage gestation period obtained for dams mated to males previously treated but have not received ARVs for another spermatogenic cycle (56 days) to check if effects could resolve. Thus only the females were still on therapy at the repeat mating.

^cBoth parents had been on therapy but at repeat mating, only the dams were currently on therapy as the males had been withdrawn for one full spermatogenic cycle.

^†Single birth recorded, thus SD could not be calculated.

Using ANOVA, significantly shorter gestation periods was observed only for the NVP “both-parents” treated groups at first mating and for the ZVP “father-only” treated groups at repeat mating when the treatment groups were compared to the untreated control.