This article is originally written by Prof. Dr. Rajan Bhonsle. This is  
one of the most common questions posed by couples expecting their first 
 child. Their lack of knowledge regarding the correct method, timing and
  frequency cause varied misconceptions and at times, a total withdrawal
  from sex. This often backfires, as the woman, owing to her 
psychological  state and emotional needs, fails to understand the 
behavioral changes  in her partner. Here's what to expect.
 Emotions on high 
During pregnancy, a woman's mental make-up undergoes a dramatic change. 
 She becomes emotional and sometimes oversensitive. The way her needs  
are acknowledged (or dismissed) affects her mental state and thereby the
 fetus as well. If she feels that her husband is not adequately  
responsive, she may get irritable, and suffer from insomnia,loss of  
appetite or over-stimulated hunger.
Most men are unaware that  their behavior often causes these emotional 
upheavals. Many take the  easy way out and take their wife to the 
doctor, without realizing that  she simply needs her husband to 
understand her moods, feelings and  anxieties.
 Discrepancy in sex drives 
The changes taking place in the mother-to-be are part of her biological 
 make-up. Hormonal and chemical changes prepare her for conception,  
pregnancy and childbearing. The awareness that she is pregnant creates  
new aspirations and sexual relations go down the priority ladder. There 
 is, however, no such biological change in the man. He needs to make  
himself aware of the physical and emotional demands of fatherhood, but  
continues to feel the urge for intercourse. In such a situation, it is  
essential that he does not force this one-sided need on his pregnant  
wife.
 For intercourse 
Though a woman may not have strong sexual urges, she does need warm and 
 gentle physical contact and caressing. In the process, if she is  
aroused and willing, they can have intercourse too. However...
- Avoid the missionary (man-superior) 
position. Woman on top position is  advisable, or they both could be in a
 sitting position, so that there is  no pressure on her abdomen and that
 movement is gentle.
 
- The  'spoon position' is also 
recommended. The position is when the couple  lie on their sides, their 
legs bent upwards, both facing in the same  direction, with the man 
behind the woman. It is called the 'spoon'  position because it is like 
two spoons, one nestling inside the other.  This is a very 'gentle' 
position as neither partner is putting any  weight on the other, and it 
is particularly good for making love to a  pregnant woman.
 
 Watch out for 
- If, during missionary position, the man is on the top, his weight  
bears down on the woman, and without his realization, the movements can 
 become rough. This, in turn, can disturb the fetus.
 
- Intercourse should be avoided from the sixth to the twelfth week of 
 the pregnancy, as it can cause miscarriage. Sexual abstinence is  
recommended during the last two months of pregnancy as well. At this  
time, if one indulges in sexual intercourse, there is risk of the  
essential amniotic fluid leaking out, causing complications.
 
- During the fourth to seventh month of pregnancy, intercourse is allowed unless you are otherwise advised for medical reasons.
 
- Sexual acts such as oral and anal sex should be avoided.
 
 Word of caution 
During pregnancy, a woman does not retain her shapely figure. It is  
possible that the man may be sexually drawn to other women. In fact, men
  are often tempted to indulge in extra-marital affairs during this 
time.  A woman's needs during pregnancy undergo a major transition. It's
  certainly not right, if the husband, instead of understanding this  
change, enters a relationship outside marriage.
This can be dealt  with if the man is equally involved with the 
pregnancy. In fact, the  couple can create deeper bonds during this 
period. Being present during  sonograph sessions, choosing the baby's 
name, his/her new clothes, etc  can help men grow in their new role.