Related substances (GC) (Sum of peaks with a relative retention less than that of benzyl alcohol) â¤ 0.02 %: Related substances (GC) (Sum of peaks with a relative retention greater than that of benzyl alcohol) â¤ 0.20 %: Related substances (GC) (disregard limit) â¤ 0.0001 %: Benzene (GC) â¤ 0.0002 %: Chlorobenzene (GC) â¤ 0.01 %: Toluene (GC)
If you're carrying more than one baby, chances are good you'll deliver early. Twins are usually born around 36 weeks -- four weeks early. Triplets arrive at about 33 weeks, and quads often make their debut at 31 weeks.
In Central Africa there are 18â30 twin sets (or 36â60 twins) per 1,000 live births. In Latin America, South Asia, and Southeast Asia, the lowest rates are found; only 6â9 twin sets per 1,000 live births. North America and Europe have intermediate rates of 9â16 twin sets per 1,000 live births. Multiple pregnancies are much less likely to carry to full term than single births, with twin pregnancies lasting only 37 weeks (3 weeks less than full term) on average.