You need to put both children in the pair onto a single record. I will paste below the lines to do this in Stata. I do not use SPSS. Perhaps you can figure out the Stata lines or find someone to translate them.

I use the BR file rather than the KR file, just because there is no need to restrict to births in the past five years. The procedure involves scratch files (intermediate work files that don't need to be saved). You will have to change the paths.

set more off
cd e:\DHS\DHS_data\scratch

use "C:\Users\26216\ICF\Analysis - Shared Resources\Data\DHSdata\IDBR63FL.DTA"

* Construct a data file that has the b variables for both children of a twin birth on one record

* Must allow for the possibility that a mother may have more than one set of twins

numlabel,add
tab b0
keep if b0==1 | b0==2

keep v0* b*
drop b9-b16
rename b* b*_
egen sequence=seq(),by(v001 v002 v003)

reshape wide b*_, i(v001 v002 v003) j(sequence)
tab1 b0*
* 11 women had two pairs of twins; must move them down

save ID63_twins1234.dta, replace
keep v* b*3 b*4
rename b*3 b*1
rename b*4 b*2
save ID63_twins34.dta, replace

use ID63_twins1234.dta, replace
keep v* b*1 b*2
append using ID63_twins34.dta

sort v002 v002 v003 bord_1
save ID63_twins12.dta, replace