Gases that contribute to the greenhouse effect include: 1  Water vapor. 2  Carbon dioxide (CO 2). 3  Methane. 4  Nitrous oxide. 5  Chlorofluorocarbons (CFCs).
You can start maternity leave any time from 11 weeks before the beginning of the week your baby's due. You can bring the date forward if you need to take time off work for pregnancy-related reasons within four weeks of the expected birth date. Your employer may make you start your leave from then.
If you are working, consider taking maternity leave as early as you can. This makes sense anyway because carrying twins is hard work, and most twins arrive earlier than single babies (NCCWCH 2011: 128) . More than half of twins arrive early, before 37 weeks (NCCWCH 2011: 120, Tamba 2012) .Talk to your midwife or doctor if you are feeling down about your pregnancy (NICE 2011) .f you are working, consider taking maternity leave as early as you can. This makes sense anyway because carrying twins is hard work, and most twins arrive earlier than single babies (NCCWCH 2011: 128) . More than half of twins arrive early, before 37 weeks (NCCWCH 2011: 120, Tamba 2012) .