Twins or multiple pregnancies are fairly common now – due to the average increase in maternal age and various assisted reproductive therapies (such as IVF). The chance of conceiving twins increases for women over the age of 35 and ovulation-inducing drugs, fertility treatment and in-vitro fertilization increase the odds of having twins and multiples.
Twins are of two basic types – identical and fraternal. Identical twins are formed when one fertilised egg (ovum) splits and develops two babies with exactly the same genetic information. Fraternal twins, where two eggs (ova) are fertilised by two sperm and hence, produce two genetically unique children. Hence, identical twins will always be of the same gender, while fraternal twins may be the same or different gender.
Multiple pregnancy results in elevated levels of HCG – the early pregnancy hormone. This often results in increased nausea and morning (or all-day) sickness.
All the early signs of pregnancy become exaggerated in multiple pregnancies – Breasts tenderness, frequency of urination, constipation, feeling very hungry all the time and excessive tiredness.
In the second trimester, some mothers may experience difficulty in breathing, increased heartburn or acidity, swelling (edema) of the hands and legs, abdominal enlargement and excessive fetal movements. Anemia (decreased hemoglobin) is also common with twin and multiple pregnancies, which leads to excessive fatigue. Other problems such as increased blood pressure (pre-eclampsia) may develop during the second trimester.